1. What is your ecological footprint? (That is, if everyone lived like you, how many earths would it take to support the world population?)
3.94 Earths
2. As the world population grows, how will this impact the amount of resources (food, electricity, water, etc.) each person can consume and still remain within the sustainability of our planet? That is, what lifestyle changes will we need to make in order to ensure there is enough food and energy to sustain everyone?
There will be a large decrease in food and natural resources, and a rise in energy use. As for lifestyle changes, I think a large population as a whole don't really care because of their own unawareness or disbeliefs (such as people who say global warming is bs), but people are capable to make changes to ensure that less and less resources are being wasted.
3. What is the IPCC? What does it do?
The IPCC is the intergovernmental panel on climate change. It is an organization to get awareness on the climate shifts and potential consequences.
4. Which climates require the most energy and the least energy on average to live in? (Give an example of a country for each)
Cold climates require the most energy (such as Russia) and tropical, relatively dry including savannahs (example: Brazil)
5. What is the Climate Action Network? What does it do?
The Climate Action Network (CAN) is an networkof 500 Non-Governmental Organizations promoting governments and individuals to take actions in limiting the human-induced climate changes to a safe level.
6. How do energy efficient appliances, line-drying your clothes, and using compact fluorescent light bulbs each help to reduce carbon emissions?
Energy efficient appliances, line-drying clothes, and using compact fluorescent light bulbs collectively impact carbon emission output even though at a glance people don't think much about them. More work is done (kW-hrs) if we did not have energy efficient appliances or used the dryer all the time or using regular light bulbs; not only does it raise carbon emissions, but raises your electricity bills too!
7. Why are compact urban living and rural living more energy efficient than sprawling suburbs?
The thing about compact urban living is that it has lots of local and commercial buildings (walking distance). Rural living take very few trips if they need to go to the store or something and rely on themselves for resources. In suburban areas more energy is used per person because public/commercial transportation is varied and also housing is a factor.
8. What are carbon offsets?
Carbon offsets are offsets that help people calculate their carbon footprints and are used to try and make vehicles, houses or individual use carbon neutral.
9. Why does eating meat require more energy than eating plants?
There is much more room and energy involved in growing, feeding and allocating room to animals (meat) rather than grow and cultivating plants.
10. How do food miles and food processing and packaging play a role in a person’s ecological footprint? How do personal and community gardens help alleviate this?
The value of transporting and refrigerating requires energy, food that comes in paper uses trees. It's more advantageous for the environment if people buy food and groceries at local markets. Also, research shows that community or personal gardens make an impact on the value of food produced per year.
11. What is a “food footprint?” What is a “housing footprint?”
Food footprint is how large the food you eat energy-intensive wise, from raising and space to grow.
12. What construction and design features contribute to green buildings?
Passive solar heating, water efficient fixtures, recycled materials, and other green building materials
13. Finish the following statement: Energy is required to deliver and treat fresh water. We can reduce our water footprint by using water saving features and adopting water conservation habits.
14. Describe two benefits of “green” cleaning products.
No harmful chemicals
Won't contaminate water, fish, or wildlife (chemicals that leak into rivers, oceans, lakes)
15. What is planned obsolescence? How can we counter it?
Planned obsolescence is deliberate manufacturing of products that wear out quickly. To avoid this, we should try to repair as much as possible and only buy only products that are designed to last.
16. What are the five environmental and economic benefits of recycling?
Reduced landfill space
Fewer demands for raw materials
Less air and water pollution
Lower waste-disposal bills
Cheaper goods
17. Click the “Reduce your footprint” link at the end of the survey and write a one-paragraph plan for how you intend to reduce your footprint. Your plan should include a list of behaviors you are committed to changing. Ideally, I would like you to select at least one behavior from each of the seven categories on the “Reduce your footprint” page that you are going to work on.
To reduce my footprint, I suppose I can do more carpooling, but there's always a problem in trying to find a person to carpool with since schedules don't necessarily match. I don't own a home yet, so I don't think I could do anything about housing footprints except to turn off any electronics I'm not using or water-saving habits, which I already do. However I think I would have to work on my food footprint the most, such as eating less meat, but meat is so good!
Thursday, May 6, 2010
Saturday, May 1, 2010
Why you can read this - and the chimps can't
Though genes are over 90% similar between chimpanzees and humans, the way the gene expression occurs still differs. "In brain cells, the number of genes and the proteins they expressed differed at least five times more between humans and chimps than among the other species in the study." Those differences can make up what how the brain works from genes on and off taking place in the human brain and chimpanzee brain such as reading.
Humans, Chimps Not as Closely Relasted as Thought?
Studies showed that the DNA is a few more percent different than expected (from about 98.5% to 95%). The causes that relate to this shift is possible occurrences of mutations - substitution, insertion, and deletion in the nucleotides. By studying the human and chimpanzee differences, researchers hope to find insights on illnesses that affect humans regularly and not chimpanzees.
Friday, April 30, 2010
Humans: Riddle of the Bones
1. What is "Lucy" and how did it get its name?
Lucy is a fossil of the A. afarensis species and shows some of the earliest human ancestors. It got its name from the song "Lucy in the Sky with Diamonds" which was a song that was playing.
2. Which hominid species does this activity focus on?
A. afarensis
3. Why do scientists believe these species all belong to the same family?
Found various fossils and were known as the First Family. They were the remains of 13 individuals and had characteristics that showed they were similar from one another species.
4. How old is each set of fossils shown in this activity?
Both the First Family fossil set and Lucy are 3.2 million years old, the Hadar Skull is 3.0 million years old & the Laetoli Footprints are 3.6 million years old.
5. Based on the description of each set of bones and the footprints, did this species live in trees or on land? Explain and defend your answer by referencing the evidence in your explanation.
I believe land, because Lucy's leg bones showed it being angular inwards as in humans
6. How did males and females of this species differ?
Males have larger muscle scars and females have a wider pelvic inlet.
7. How did the brains of this species compare to modern humans? What evidence supports this?
Small-sized brains about the size of chimps
Lucy is a fossil of the A. afarensis species and shows some of the earliest human ancestors. It got its name from the song "Lucy in the Sky with Diamonds" which was a song that was playing.
2. Which hominid species does this activity focus on?
A. afarensis
3. Why do scientists believe these species all belong to the same family?
Found various fossils and were known as the First Family. They were the remains of 13 individuals and had characteristics that showed they were similar from one another species.
4. How old is each set of fossils shown in this activity?
Both the First Family fossil set and Lucy are 3.2 million years old, the Hadar Skull is 3.0 million years old & the Laetoli Footprints are 3.6 million years old.
5. Based on the description of each set of bones and the footprints, did this species live in trees or on land? Explain and defend your answer by referencing the evidence in your explanation.
I believe land, because Lucy's leg bones showed it being angular inwards as in humans
6. How did males and females of this species differ?
Males have larger muscle scars and females have a wider pelvic inlet.
7. How did the brains of this species compare to modern humans? What evidence supports this?
Small-sized brains about the size of chimps
Humans: Babies By Design
There are always pros and cons especially for creating babies by design. It would be quite fortunate if all babies were genetically modified so that they wouldn't have an inevitable death because of a disease, but parents on their own should be aware of any genetic diseases that might affect them in creating a baby. However, I would most likely support the should not create babies by design, because our genetic code creates our own individualism and that's something I find as aesthetic.
Humans: Origins of Humankind
Species that lead to humans:
Orrorin tugensis
Australopithecus anamensis
Kenyanthropus platyops
Homo habilis
Homo erectus
Homo sapiens
Orrorin tugensis
Australopithecus anamensis
Kenyanthropus platyops
Homo habilis
Homo erectus
Homo sapiens
Survival: Microbe Clock
A) Describe in detail how Streptococcus pneumoniae has developed antibiotic resistance over the past century.
Streptococcus pneumonia has developed resistance over time against antibiotics and over drugs. Those bacteria that remain rapidly evolve and replicate leaving those that are susceptible to die out, and leaving the ones which are resistant to survive.
B) Start the clock. The one minute of division here represents 186 days of actual division. How many times did the cells divide in this time? How many total cells resulted at the end of this time? How many mutations occcurred in the population during this time?
Replicated 13,391 million times; population of 313, 753 million; 1,326 mutations
Streptococcus pneumonia has developed resistance over time against antibiotics and over drugs. Those bacteria that remain rapidly evolve and replicate leaving those that are susceptible to die out, and leaving the ones which are resistant to survive.
B) Start the clock. The one minute of division here represents 186 days of actual division. How many times did the cells divide in this time? How many total cells resulted at the end of this time? How many mutations occcurred in the population during this time?
Replicated 13,391 million times; population of 313, 753 million; 1,326 mutations
Change: Deep Time
1. Atmosphere forms: Precambrian Eon; Hadean 4,500 mya
2. Earth's core forms: Precambrian Eon; Hadean 4,400 mya
3. First living organisms evolve(prokaryotic cells): Precambrian Eon; Hadean 3,850 mya
4.First eukaryotic cells evolve: Precambrian Eon; Archaean 2,700 mya
5. First multicellular organisms evolve(algae): Precambrian Eon; Proterozoic 1,200 mya
6. Ozone layer forms: Precambrian Eon; Proterozoic 600 mya
7. First Chordates evolve: Paleozoic Era; Cambrian 535 mya
A chordate are any of the numerous animals belonging to the the family Chordata having at some stage of development a dorsal nerve cord.
8. First land plants evolve: Paleozoic Era; Ordovician 480 mya
9. First land animals (bugs) evolve: Paleozoic Era; Carboniferons 420 mya
10. First land vertebrates evolve: Paleozoic Era; Devonian 375 mya
A vertebrate is an animal having a backbone or spinal column.
11. First flowering plants evolved: Paleozoic Era; Devonian 360 mya
12. First reptiles evolve: Paleozoic Era; Permian 275 mya
13. Pangaea forms: Paleozoic Era; Permian 280 mya
The Pangaea is a theory that states that all present continents were once together and collectively known as a "supercontinent" called Pangaea.
14. First mammals evolve: Mesozoic Era; Triassic 220 mya
15. First birds evolv: Mesozoic Era; Jurassic 150 mya
16. First primates evolve: Cenozoic Era; Paleocene 60mya
17. Continents reach their present-day formation: Cenozoic Era; Eocene 40mya
18. First apes evolve from the primate lineage: Cenozoic Era; Oligocene 25 mya
19. Hominids evolve from the ape lineage: Cenozoic Era; Pliocene 5.2 mya
A hominid is any member of the biological primate family Hominidae.
20. First early humans evolve from the hominid lineage: Cenozoic Era; Pleistocene 0.16 mya
21. Modern humans evolve from the human lineage: Cenozoic Era; Pleistocene 0.1 mya
2. Earth's core forms: Precambrian Eon; Hadean 4,400 mya
3. First living organisms evolve(prokaryotic cells): Precambrian Eon; Hadean 3,850 mya
4.First eukaryotic cells evolve: Precambrian Eon; Archaean 2,700 mya
5. First multicellular organisms evolve(algae): Precambrian Eon; Proterozoic 1,200 mya
6. Ozone layer forms: Precambrian Eon; Proterozoic 600 mya
7. First Chordates evolve: Paleozoic Era; Cambrian 535 mya
A chordate are any of the numerous animals belonging to the the family Chordata having at some stage of development a dorsal nerve cord.
8. First land plants evolve: Paleozoic Era; Ordovician 480 mya
9. First land animals (bugs) evolve: Paleozoic Era; Carboniferons 420 mya
10. First land vertebrates evolve: Paleozoic Era; Devonian 375 mya
A vertebrate is an animal having a backbone or spinal column.
11. First flowering plants evolved: Paleozoic Era; Devonian 360 mya
12. First reptiles evolve: Paleozoic Era; Permian 275 mya
13. Pangaea forms: Paleozoic Era; Permian 280 mya
The Pangaea is a theory that states that all present continents were once together and collectively known as a "supercontinent" called Pangaea.
14. First mammals evolve: Mesozoic Era; Triassic 220 mya
15. First birds evolv: Mesozoic Era; Jurassic 150 mya
16. First primates evolve: Cenozoic Era; Paleocene 60mya
17. Continents reach their present-day formation: Cenozoic Era; Eocene 40mya
18. First apes evolve from the primate lineage: Cenozoic Era; Oligocene 25 mya
19. Hominids evolve from the ape lineage: Cenozoic Era; Pliocene 5.2 mya
A hominid is any member of the biological primate family Hominidae.
20. First early humans evolve from the hominid lineage: Cenozoic Era; Pleistocene 0.16 mya
21. Modern humans evolve from the human lineage: Cenozoic Era; Pleistocene 0.1 mya
Darwin: An Origin of Species activity
Overview: Hurricane hits the mainland and forces many pollenpeepers offshore islands and struggle to survive. The birds that are well adapted will survive will pass their genes, while those that aren't will wither out.
5mya: Hurricane hits and blows off the pollenpeepers to 3 other offshore lands - Windsor Island, Norcross Island, and Warwick Archipelago.
4mya: Population grows on all 4 lands.
3mya: In mainland, a beak suited better for the environment grows. Food abundance rises and predators (lizards) come ashore on the Norcross.
2mya: Mainland habitat becomes more lush, providing more food for the environment. On Windsor Island, some move back mainland. On the Warwick Archipelago, population diversifies
1mya: Mainland - mainland and Windsor birds interbreed. Warwick Archipelago - lowland forest population begins feeding on nectar. Immigrants come to the Windsor Island and Norcross.
Present: Windor Island - short blunt beaks become obsolete. Norcross - some specialize in seedeaters.
5mya: Hurricane hits and blows off the pollenpeepers to 3 other offshore lands - Windsor Island, Norcross Island, and Warwick Archipelago.
4mya: Population grows on all 4 lands.
3mya: In mainland, a beak suited better for the environment grows. Food abundance rises and predators (lizards) come ashore on the Norcross.
2mya: Mainland habitat becomes more lush, providing more food for the environment. On Windsor Island, some move back mainland. On the Warwick Archipelago, population diversifies
1mya: Mainland - mainland and Windsor birds interbreed. Warwick Archipelago - lowland forest population begins feeding on nectar. Immigrants come to the Windsor Island and Norcross.
Present: Windor Island - short blunt beaks become obsolete. Norcross - some specialize in seedeaters.
Sunday, April 4, 2010
1. Which regulatory mechanisms occur at the DNA-level, which occur at the protein-level?
DNA level - transcription, chromosome remodeling, acetylation/methylation, activators/repressors, siRNA
protein level - feedback inhibition; allosteric/competitive inhibition
2. How do acetylation, methylation, repressors, activators, and siRNA control gene expression? What role do inducers play?
Acetylation loosens the DNA, allowing transcription factors to bind
Methylation is the opposite of acetylation, it crams the DNA close together to that it denies access
Repressor binds to regulatory sites blocking attachment of transcription factors
Activators binds to the regulatory sites
Inducers are crucial since they have the ability to control repressors and activators
3. What is an enhancer and how does it help control how much of a particular protein is made?
An enhancer is a short region of DNA that can bind to activators - are far from the promoter site. Enhancers increase the transcription process, therefore increasing amount of protein to be made.
4. How do allosteric inhibition and competitive inhibition differ in the ways they accomplish feedback inhibition?
Allosteric inhibition binds, changing the shape of the enzyme, while competitive inhibition gets in the way by blocking the entrance to an enzyme
5. What are the three phases of the cell cycle? What occurs at each phase?
G1, S, and G2 phase. G1 and G2 is similar in that they are the phase were the cell is given time to grow to its stable size, and in the S phase, DNA synthesis occurs
6. What are the four phases of mitosis? What occurs at each phase?
Prophase - DNA condenses and mitotic spindles start to develop
Metaphase - Linear alignment of chromatids at the center of the cell
Anaphase - Mitotic spindles pull the sister chromatids apart so that they are on each side of the cell
Telophase/Cytokinesis - Nuclear envelop reforms and the cell is divided by the cell membranes separating
7. What are cell cycle checkpoints? Why are they important?
Cell cycle checkpoints are areas where the enzymes examine whether or not the cell cycle is progressing properly to prevent mutations or problems that can occur.
8.What is apoptosis? What role does it play in the cell cycle?
Apoptosis is when a cell "suicides" or kills itself, it helps in the cell cycle so that it prevents further cell division in mutated cells
9. What is the difference between chromatin and chromosomes?
Chromosomes are condensed versions of chromatin.
10. What is the role of the centromere? (What would happen without it?)
Centromere holds the sister chromatids together, without it anaphase would most likely not correctly separate to each side of the cell (the whole chromosome might go to one side).
11. What is the difference between a chromatid and a chromosome?
Two strands of chromatid forms a chromosome
12. What events must happen in order for two sister chromatids to separate from one another and move to opposite sides of the cell? (What happens at the centromere? What happens to the centromere? What is the role of the mitotic spindle?)
The kinetochore microtubules connect to the sister chromatids and line up during metaphase. During Anaphase, the sister chromatids are pulled apart, and the centromere that hold them together are actually proteins that deactivate allowing, the separation of them. The mitotic spindles are shortened and are turned into centrioles and conserved for future mitosis processes
13. What would happen if two sister chromatids moved to the same side of the cell?
Of the pair of cell through mitosis, one will have an abundance of chromosomes, while the other cell will be lacking.
14. What happens to the mitotic spindle after mitosis?
Forms into the cytoskeleton and returns back into shape of microtubules and centrioles
15. What are gametes? Where are they made in the body? How are they made?
Sex cells; eggs in females made in the ovaries, or sperm in the male made in the testes; made by meiosis
16. What are the eight phases of meiosis? What occurs during each phase? How does meiosis differ from mitosis?
Prophase I - DNA condenses and microtubles start to assembles.
Metaphase I - Homologous chromosomes alignment at center of cell; crossing over occurs
Anaphase I - Separation of homologous chromosomes
Telophase/Cytokinesis I - Cell is divided, both daughter cell gets 23 pairs of chromatids each; results in two haploids
Prophase II - Microtubules prepare for Metaphase II
Metaphase II - 23 chromatid pairs line up at the center
Anaphase II - Centromere divide and split the the 46 chromosomes; sister chromatids by mitosis
Telophase/Cytokinesis II - Divides both cells into halves, making four haploids (gametes)
17. How do crossing over and random assortment “mix up” genes so that children are genetically different from their parents?
Crossing over occurs on any part of the chromosome and since there are so much DNA in the chromosome, there are a number of possibilities where crossing over can occur. Random assortment further helps but most of the genetic variation is due to crossing over.
18. Why are insertion and deletion mutations usually more harmful than substitution mutations?
Insertion and deletion mutations is more harmful because substitution is more likely to an equivalent condon since there are 20 codons for 64 different combinations.
19. How does nondisjunction affect the genes present in an organism? Specifically, why does it cause deformities?
Nondisjunction affects cells undergoing division and result in an extra or missing one chromosome.
20. What “super powers” must a cell acquire to become cancerous? How does it acquire these powers?
Active oncogenes and inactive tumor suppressor genes; by mutation which can alter these gene's control of activation and deactivation.
21. Compare and contrast oncogenes and tumor suppressor genes. What are they? How are they similar? How are they different?
Oncogenes and tumor suppressor genes both play a role in controlling cell division. Oncogenes tells cells to keep dividing while tumor suppressor genes halt or slow the process of cell division. Oncogenes help cancer, tumor suppressors help against cancer.
22. Why is cancer primarily a disease of old age?
In old age, the wear in the body's immune system and all the regulatory functions can allow a cancerous to take advantage by "cheating the system."
23. How do mutations cause genetic variation? Is this good or bad for the organism?
Mutations can create new alleles which is expressed as a new genotype. Normally it is bad, since it can cause a defect in the organism, but if it's good, it's considered evolution
24. How do genetic diseases caused by point mutations differ from those caused by chromosomal mutations like nondisjunction?
Chromosomal mutations affect a large number of DNA vs point mutations which cause a frame change in the DNA sequence
25. What causes spontaneous mutations? What causes induced mutations?
Spontaneous mutations are caused by point mutations or nondisjunction incurred during mitosis. Induced mutations are caused by mutagens.
26. How accurate is DNA replication? (That is, how often do point mutations occur?)
Errors from point mutations occur in about every 1 in 100,000 nucleotides; when an enzyme tries to fix the problem, the error rate drops to about 1 in 10 billion nucleotides in humans.
27. What type of mutation is shown here? AGTGCCGTAAC
___________________________________TCACGGCCAGTG
Point mutations (both frameshift - a nucleotide was added - and substitution)
DNA level - transcription, chromosome remodeling, acetylation/methylation, activators/repressors, siRNA
protein level - feedback inhibition; allosteric/competitive inhibition
2. How do acetylation, methylation, repressors, activators, and siRNA control gene expression? What role do inducers play?
Acetylation loosens the DNA, allowing transcription factors to bind
Methylation is the opposite of acetylation, it crams the DNA close together to that it denies access
Repressor binds to regulatory sites blocking attachment of transcription factors
Activators binds to the regulatory sites
Inducers are crucial since they have the ability to control repressors and activators
3. What is an enhancer and how does it help control how much of a particular protein is made?
An enhancer is a short region of DNA that can bind to activators - are far from the promoter site. Enhancers increase the transcription process, therefore increasing amount of protein to be made.
4. How do allosteric inhibition and competitive inhibition differ in the ways they accomplish feedback inhibition?
Allosteric inhibition binds, changing the shape of the enzyme, while competitive inhibition gets in the way by blocking the entrance to an enzyme
5. What are the three phases of the cell cycle? What occurs at each phase?
G1, S, and G2 phase. G1 and G2 is similar in that they are the phase were the cell is given time to grow to its stable size, and in the S phase, DNA synthesis occurs
6. What are the four phases of mitosis? What occurs at each phase?
Prophase - DNA condenses and mitotic spindles start to develop
Metaphase - Linear alignment of chromatids at the center of the cell
Anaphase - Mitotic spindles pull the sister chromatids apart so that they are on each side of the cell
Telophase/Cytokinesis - Nuclear envelop reforms and the cell is divided by the cell membranes separating
7. What are cell cycle checkpoints? Why are they important?
Cell cycle checkpoints are areas where the enzymes examine whether or not the cell cycle is progressing properly to prevent mutations or problems that can occur.
8.What is apoptosis? What role does it play in the cell cycle?
Apoptosis is when a cell "suicides" or kills itself, it helps in the cell cycle so that it prevents further cell division in mutated cells
9. What is the difference between chromatin and chromosomes?
Chromosomes are condensed versions of chromatin.
10. What is the role of the centromere? (What would happen without it?)
Centromere holds the sister chromatids together, without it anaphase would most likely not correctly separate to each side of the cell (the whole chromosome might go to one side).
11. What is the difference between a chromatid and a chromosome?
Two strands of chromatid forms a chromosome
12. What events must happen in order for two sister chromatids to separate from one another and move to opposite sides of the cell? (What happens at the centromere? What happens to the centromere? What is the role of the mitotic spindle?)
The kinetochore microtubules connect to the sister chromatids and line up during metaphase. During Anaphase, the sister chromatids are pulled apart, and the centromere that hold them together are actually proteins that deactivate allowing, the separation of them. The mitotic spindles are shortened and are turned into centrioles and conserved for future mitosis processes
13. What would happen if two sister chromatids moved to the same side of the cell?
Of the pair of cell through mitosis, one will have an abundance of chromosomes, while the other cell will be lacking.
14. What happens to the mitotic spindle after mitosis?
Forms into the cytoskeleton and returns back into shape of microtubules and centrioles
15. What are gametes? Where are they made in the body? How are they made?
Sex cells; eggs in females made in the ovaries, or sperm in the male made in the testes; made by meiosis
16. What are the eight phases of meiosis? What occurs during each phase? How does meiosis differ from mitosis?
Prophase I - DNA condenses and microtubles start to assembles.
Metaphase I - Homologous chromosomes alignment at center of cell; crossing over occurs
Anaphase I - Separation of homologous chromosomes
Telophase/Cytokinesis I - Cell is divided, both daughter cell gets 23 pairs of chromatids each; results in two haploids
Prophase II - Microtubules prepare for Metaphase II
Metaphase II - 23 chromatid pairs line up at the center
Anaphase II - Centromere divide and split the the 46 chromosomes; sister chromatids by mitosis
Telophase/Cytokinesis II - Divides both cells into halves, making four haploids (gametes)
17. How do crossing over and random assortment “mix up” genes so that children are genetically different from their parents?
Crossing over occurs on any part of the chromosome and since there are so much DNA in the chromosome, there are a number of possibilities where crossing over can occur. Random assortment further helps but most of the genetic variation is due to crossing over.
18. Why are insertion and deletion mutations usually more harmful than substitution mutations?
Insertion and deletion mutations is more harmful because substitution is more likely to an equivalent condon since there are 20 codons for 64 different combinations.
19. How does nondisjunction affect the genes present in an organism? Specifically, why does it cause deformities?
Nondisjunction affects cells undergoing division and result in an extra or missing one chromosome.
20. What “super powers” must a cell acquire to become cancerous? How does it acquire these powers?
Active oncogenes and inactive tumor suppressor genes; by mutation which can alter these gene's control of activation and deactivation.
21. Compare and contrast oncogenes and tumor suppressor genes. What are they? How are they similar? How are they different?
Oncogenes and tumor suppressor genes both play a role in controlling cell division. Oncogenes tells cells to keep dividing while tumor suppressor genes halt or slow the process of cell division. Oncogenes help cancer, tumor suppressors help against cancer.
22. Why is cancer primarily a disease of old age?
In old age, the wear in the body's immune system and all the regulatory functions can allow a cancerous to take advantage by "cheating the system."
23. How do mutations cause genetic variation? Is this good or bad for the organism?
Mutations can create new alleles which is expressed as a new genotype. Normally it is bad, since it can cause a defect in the organism, but if it's good, it's considered evolution
24. How do genetic diseases caused by point mutations differ from those caused by chromosomal mutations like nondisjunction?
Chromosomal mutations affect a large number of DNA vs point mutations which cause a frame change in the DNA sequence
25. What causes spontaneous mutations? What causes induced mutations?
Spontaneous mutations are caused by point mutations or nondisjunction incurred during mitosis. Induced mutations are caused by mutagens.
26. How accurate is DNA replication? (That is, how often do point mutations occur?)
Errors from point mutations occur in about every 1 in 100,000 nucleotides; when an enzyme tries to fix the problem, the error rate drops to about 1 in 10 billion nucleotides in humans.
27. What type of mutation is shown here? AGTGCCGTAAC
___________________________________TCACGGCCAGTG
Point mutations (both frameshift - a nucleotide was added - and substitution)
Saturday, April 3, 2010
Tour of the Basics
http://learn.genetics.utah.edu/content/begin/tour/
What Is DNA?
DNA (deoxyribose nucleic acid) is double helix structured composed of two strands of A, T, G, and Cs that combine with each other in the complimentary strand, by specific pairs - A with T and G with C - and each collectively, are used in a gene.
What is a Gene?
Genes are made up of DNA and are specific in building proteins. If there is an error or mutation within the gene, it will cause a disorder and may be disadvantageous. Since genes contain instructions for building proteins, there are in fact many sorts of a proteins, which result in functions for all sorts of things.
What is a Chromosome?
A chromosome is a packaged fit of DNA into a cell. Depending on the organism, each cell holds a different number of chromosomes, for humans, a cell holds 46 chromosomes. By looking at chromosomes, you can observe something such as the sex of a human for example; you can see the difference between female chromosome (XX) and male chromosome (XY).
What is a Protein?
Each protein has a specific role such as receptor proteins, sending signals across the nerve cells into the brain, or structural to make the cell stay in it's shape. There are many types of proteins other than these two that play specific roles in the body. To make proteins, it uses genes as it's "blueprint" by making mRNA then travels with later is moved into the ribosomes to produce more.
What is Heredity?
Heredity is the set of traits that defined by our genes. It is both contributed by environmental factors (chemical exposure) and the chromosomes inherited from our parents, both father and mother. Because of random assortment, each child will never have the exact combination of chromosomes.
What is a Trait?
A trait is a unique feature that separates one person from another noticeably. There are three types, physical behavioral, or predisposition on medical condition. Each can be genetically or environmentally influenced. The genes or alleles passed on by both parents (one from each) determine what trait someone will have.
What Is DNA?
DNA (deoxyribose nucleic acid) is double helix structured composed of two strands of A, T, G, and Cs that combine with each other in the complimentary strand, by specific pairs - A with T and G with C - and each collectively, are used in a gene.
What is a Gene?
Genes are made up of DNA and are specific in building proteins. If there is an error or mutation within the gene, it will cause a disorder and may be disadvantageous. Since genes contain instructions for building proteins, there are in fact many sorts of a proteins, which result in functions for all sorts of things.
What is a Chromosome?
A chromosome is a packaged fit of DNA into a cell. Depending on the organism, each cell holds a different number of chromosomes, for humans, a cell holds 46 chromosomes. By looking at chromosomes, you can observe something such as the sex of a human for example; you can see the difference between female chromosome (XX) and male chromosome (XY).
What is a Protein?
Each protein has a specific role such as receptor proteins, sending signals across the nerve cells into the brain, or structural to make the cell stay in it's shape. There are many types of proteins other than these two that play specific roles in the body. To make proteins, it uses genes as it's "blueprint" by making mRNA then travels with later is moved into the ribosomes to produce more.
What is Heredity?
Heredity is the set of traits that defined by our genes. It is both contributed by environmental factors (chemical exposure) and the chromosomes inherited from our parents, both father and mother. Because of random assortment, each child will never have the exact combination of chromosomes.
What is a Trait?
A trait is a unique feature that separates one person from another noticeably. There are three types, physical behavioral, or predisposition on medical condition. Each can be genetically or environmentally influenced. The genes or alleles passed on by both parents (one from each) determine what trait someone will have.
Friday, March 19, 2010
DNA Replication and Protein Synthesis
1. Why is DNA synthesis said to be “semiconservative”?
Tthe DNA that splits serves as a template for DNA synthesis, the template from the "old" DNA is combined with a new strand of DNA, resulting in two DNA strands composed of both a new and an old strand, therefore, semi-conservative.
2. What role do DNA polymerase, DNA primase (a type of RNA polymerase), helicase, topoisomerase, RNase H, and ligase play in DNA replication?
DNA polymerase: forms the complimentary strand in 5' to 3' (reads 3' to 5' )
DNA primase: create the formation of nucleotides (for RNA primer)
Helicase: breaks bonds between DNA strands
Topoisomerase: unwinds DNA strand
RNase H: removes the RNA primers
Ligase: "glues" the Okazaki fragments together
3. What is the difference between how the leading strand and lagging strand are copied during DNA replication? Why do they have to be synthesized differently in this fashion?
The synthesis of the leading strand is continuous while the lagging strand is done in Okazaki fragments since DNA polymerase can only read from the 5' to 3' direction; DNA synthese takes much more time in the lagging strand than the leading strand.
4. What would happen if insufficient RNase H were produced by a cell? What if insufficient ligase were produced by a cell?
Insufficient RNase H would leave the RNA primers still in tact and insufficient ligase would leave gaps between the fragments. As a result, the DNA would likely be defective.
5. What are four key differences between DNA polymerase and RNA polymerase? (“they are difference molecules” doesn’t count as one!)
-DNA requires a primer for synthesis, RNA does not
-RNA polymerase occurs only on one strand of DNA; each strand is a separate set of genes
-RNA polymerase acts as DNA polymerase, helicase, AND topoisomerase (performs three functions in one!) while DNA polymerase does only one function
-RNA nucleotide base pairing vs. DNA nucleotide base pairing during transcription (uracil vs. thymine)
6. Compare and contrast codons and anticodons.
Codons are 3-sequence nucleotide in mRNA, anticodons are tRNA that bind complimentary to the 3-sequence nucleotide in mRNA; anticodons are also dependent factors while codons are independent factors. Anticodons also carry a specific amino acid.
7. What is alternative splicing? Why is it necessary in eukaryotes?
Alternative splicing is the removal of introns, leaving exons to attack to themselves; when exons reform, they can be combined in different sequences which can create various proteins from the same gene which is necessary in eukaryotes.
8. During translation, what amino acid sequence would the following mRNA segment be converted into: AUGGACAUUGAACCG?
Met-Asp-Ile-Glu-Pro
9. How come there are only 20 amino acids when there are 64 different codons?
Many codons have the same amino acid code
10. How come prokaryotes can both transcribe and translate a gene at the same time, but eukaryotes cannot?
In eukaryotes, transcription occurs in the nucleus while translation occurs in the cytoplasm; prokayotes have no nucleus therefore they do both at the same time.
Tthe DNA that splits serves as a template for DNA synthesis, the template from the "old" DNA is combined with a new strand of DNA, resulting in two DNA strands composed of both a new and an old strand, therefore, semi-conservative.
2. What role do DNA polymerase, DNA primase (a type of RNA polymerase), helicase, topoisomerase, RNase H, and ligase play in DNA replication?
DNA polymerase: forms the complimentary strand in 5' to 3' (reads 3' to 5' )
DNA primase: create the formation of nucleotides (for RNA primer)
Helicase: breaks bonds between DNA strands
Topoisomerase: unwinds DNA strand
RNase H: removes the RNA primers
Ligase: "glues" the Okazaki fragments together
3. What is the difference between how the leading strand and lagging strand are copied during DNA replication? Why do they have to be synthesized differently in this fashion?
The synthesis of the leading strand is continuous while the lagging strand is done in Okazaki fragments since DNA polymerase can only read from the 5' to 3' direction; DNA synthese takes much more time in the lagging strand than the leading strand.
4. What would happen if insufficient RNase H were produced by a cell? What if insufficient ligase were produced by a cell?
Insufficient RNase H would leave the RNA primers still in tact and insufficient ligase would leave gaps between the fragments. As a result, the DNA would likely be defective.
5. What are four key differences between DNA polymerase and RNA polymerase? (“they are difference molecules” doesn’t count as one!)
-DNA requires a primer for synthesis, RNA does not
-RNA polymerase occurs only on one strand of DNA; each strand is a separate set of genes
-RNA polymerase acts as DNA polymerase, helicase, AND topoisomerase (performs three functions in one!) while DNA polymerase does only one function
-RNA nucleotide base pairing vs. DNA nucleotide base pairing during transcription (uracil vs. thymine)
6. Compare and contrast codons and anticodons.
Codons are 3-sequence nucleotide in mRNA, anticodons are tRNA that bind complimentary to the 3-sequence nucleotide in mRNA; anticodons are also dependent factors while codons are independent factors. Anticodons also carry a specific amino acid.
7. What is alternative splicing? Why is it necessary in eukaryotes?
Alternative splicing is the removal of introns, leaving exons to attack to themselves; when exons reform, they can be combined in different sequences which can create various proteins from the same gene which is necessary in eukaryotes.
8. During translation, what amino acid sequence would the following mRNA segment be converted into: AUGGACAUUGAACCG?
Met-Asp-Ile-Glu-Pro
9. How come there are only 20 amino acids when there are 64 different codons?
Many codons have the same amino acid code
10. How come prokaryotes can both transcribe and translate a gene at the same time, but eukaryotes cannot?
In eukaryotes, transcription occurs in the nucleus while translation occurs in the cytoplasm; prokayotes have no nucleus therefore they do both at the same time.
Saturday, March 13, 2010
Insulin Review Article Questions
1. In what journal did this article appear? When?
Science, Vol. 208; 4 April 1980
2. What is the primary purpose of this paper?
Publications of findings in the nucleotide structure of preproinsulin mRNA
3. What is the structural difference between insulin and proinsulin?
ProInsulin is a precursor to insulin. Insulin has the variable C chain, while proinsulin does not.
4. What is complementary DNA (cDNA)?
A sequence of DNA nucleotides that chemically match the other strand of the double stranded structure.
5. What is meant by the "polyA tail" or "polyadenylation" of a gene?
It is the polypeptide attached to the end of chain A.
6. What is meant by the statement that "insulin A and B chains are highly conserved"?
The chains are protected from evolution (unchanging).
7. Which chain is most highly conserved?
A chain
8. What do the researchers believe is the purpose of the C chain?
To help form the 3-D shape of the proinsulin molecule
9. Why does it make sense that the C chain is more variable (less highly conserved) than the A chain and B chain?
The C chain just binds them together and doesn’t have such specific functions as chains A and B; also, the variability will not make the chain function differently.
10. What do the researchers believe is the purpose of the pre-peptide (D chain)?
To signal the transfer of the preproinsulin protein into the ER.
11. How does the human preproinsulin gene differ from rat preproinsulin (rat I and rat II)?
Different codons in the coding area.
12. What is the first codon in the coding region of the gene (at the start of the pre-peptide) and what is the first amino acid in the polypeptide?
AUG; methionine (Met)
Science, Vol. 208; 4 April 1980
2. What is the primary purpose of this paper?
Publications of findings in the nucleotide structure of preproinsulin mRNA
3. What is the structural difference between insulin and proinsulin?
ProInsulin is a precursor to insulin. Insulin has the variable C chain, while proinsulin does not.
4. What is complementary DNA (cDNA)?
A sequence of DNA nucleotides that chemically match the other strand of the double stranded structure.
5. What is meant by the "polyA tail" or "polyadenylation" of a gene?
It is the polypeptide attached to the end of chain A.
6. What is meant by the statement that "insulin A and B chains are highly conserved"?
The chains are protected from evolution (unchanging).
7. Which chain is most highly conserved?
A chain
8. What do the researchers believe is the purpose of the C chain?
To help form the 3-D shape of the proinsulin molecule
9. Why does it make sense that the C chain is more variable (less highly conserved) than the A chain and B chain?
The C chain just binds them together and doesn’t have such specific functions as chains A and B; also, the variability will not make the chain function differently.
10. What do the researchers believe is the purpose of the pre-peptide (D chain)?
To signal the transfer of the preproinsulin protein into the ER.
11. How does the human preproinsulin gene differ from rat preproinsulin (rat I and rat II)?
Different codons in the coding area.
12. What is the first codon in the coding region of the gene (at the start of the pre-peptide) and what is the first amino acid in the polypeptide?
AUG; methionine (Met)
Tuesday, February 9, 2010
Cellular Respiration & Photosynthesis
1. What happens to radiant energy that reaches earth from the sun?
It is either absorbed into the Earth's surface or reflects from the Earth's atmosphere or surface, going into space.
2. Name four greenhouse gasses in addition to water vapor.
Carbon dioxide
Chlorofluorocarbons
Methane
Nitrous Oxide
3. How do water vapor and greenhouse gasses contribute to earth’s climate?
Water vapor absorbs some heat energy and greenhouse gasses retains heat on the Earth's surface, and both combined helps keep the climate in control, except in instances of excess of one kind, such as global warming.
4. What are four sources of carbon dioxide?
Aerobic respiration
Pressure and heat from decaying matter into fossil fuels
Human pollution (technology converting fossil fuels)
Volcanoes, living organisms
5. Name three reservoirs for carbon dioxide in addition to the atmosphere.
Living organisms, bodies of water, and soil
6. What are fossil fuels? How are they made?
Fossil fuels are buried remains of ancient plants and microorganisms transformed(made) through heat and pressure for coal, oil and natural gas.
7. Where do plants get the carbon they need to build sugars?
From the CO2 in the Earth's atmosphere
8. Where do animals get the carbon they need to synthesize ATP?
Eating plants
9. How has the amount of carbon dioxide in the atmosphere changed over the past 100 years? What effect has this had on the planet’s overall climate?
The rate in which it is increasing, has changed drastically, in a negative aspect; the effect is the increase of the Earth's temperature, therefore global warming.
10. What is the difference in the chemical structure between ADP and ATP?
ADP has 2 Phosphorous bases while ATP has 3 bases
11. How does ATP transfer energy to parts of a cell?
Phosphorylation
12. What is the difference between aerobic respiration and anaerobic respiration?
One of the respiration requires Oxygen (aerobic), while the other does not (anaerobic)
13. Where do glycolysis, the citric acid cycle, chemiosmosis, and the light and dark reactions of photosynthesis occur in cells?
Mitochondria or Chloroplast of a eukaryotic cell.
14. What are the final products of glycolysis? (don’t forget the energy carriers)
2 Pyruvic acids, 2 NADH's, and net gain of 2 ATPs
15. What molecule enters the citric acid cycle? (hint: it’s not pyruvic acid)
Acetyl-CoA
16. What are the final products of the citric acid cycle?
3 NADH, 1 FADH2, 1 GTP and 2CO2 per pyruvate
17. Where does the electron transport chain get energy from to move H+ ions across the membrane into the inner membrane space?
When an electron is picked up by a protein/handed off to another, it changes shape, and this facilitates the movment of hydrogen ions from the matrix to the intermembrane space.
18. Why is oxygen needed for aerobic respiration?
The final electron receptor after breaking down glucose is Oxygen (for the H+ ions) to bond to form H2O
19. How is ATP generated via chemiosmosis? (be sure to explain the role of ATP synthase in your answer)
As hydrogen rush along its concentration gradient through ATP synthase, it uses the energy(oxidative
phosphorylation( of to produce ATP. 3ATPs per NADH and 2ATPs per FADH2
20. How many ATP are produced per NADH? Per FADH2?
3ATPs per NADH and 2ATPs per FADH2
21. How many total ATP are produced from a single glucose molecule during glycolysis followed by aerobic respiration?
38
22. What part of proteins can be metabolized for energy?
Amino acids
23. What part of lipids can be metabolized for energy?
Fatty acids and Glycerol
24. What is the purpose of fermentation? What would happen to cells if they were somehow prevented from doing it?
To oxidize the NADH carriers from glycolysis; if they were prevented from doing fermentation, the glycolysis would stop completely
25. What are stomata? What type of cells make them up?
Stomata are pores on the surface of leaves that allow gas exchange (entry for CO2 and release of O2); are made up of guard cells
26. Where does the energy come from for the light-dependent reactions of photosynthesis? Where in chloroplasts do these reactions occur?
Photons of light (mainly the sun); light-dependent reactions occur in the thylakoids
27. How do the energy carrier molecules synthesized during the light-dependent reactions of photosynthesis compare to those synthesized during cellular respiration?
Similar, except the molecule NADPH, rather than NADH.
28. Where in chloroplasts are glucose molecules synthesized? What process is responsible for their synthesis?
Stroma; Calvin cycle
29. Why is water necessary for photosynthesis? Why is carbon dioxide necessary? Why is sunlight necessary?
Water or H2O is required for the replacement of hydrogen ions along the electron transport chain.
Carbon dioxide is the core molecule to convert into sugars.
Sunlight's solar energy is used for chemical energy
30. How are rubisco and oxaloacetate similar?
Rubisco and Oxaloacetate are similar in that they both are catalysts in the beginning of either the Calvin or Kreb cycle
31. What is transpiration?
Water moving out of the plant via stomatal openings
32. Which types of plants are most vulnerable to photorespiration? Why?
C3 plants; prevention of CO2 from entering which causes photosynthesis to decline.
33. Why are C3 plants better adapted to cool, shady environments while C4 plants are better adapted to hot, sunny environments?
At high temperatures, C3 have reduced photosynthesis ands close their stomata to reduce the rate of water lost; C4 carry an extra enzyme which avoids photorespiration and continues to make sugars
34. Why is growth limited in CAM plants?
In CAM plants, the stomata opens only at night, therefore the CO2 that enters can not immediately be used because it requires energy from the sun for photosynthesis.
35. How does deforestation contribute to global warming?
Reduction of plants increase the amount CO2 in the atmosphere, since there will be less plants to take in the CO2
36. What role does the United States play in global warming?
The US is the largest nation contributing to the greenhouse effect
It is either absorbed into the Earth's surface or reflects from the Earth's atmosphere or surface, going into space.
2. Name four greenhouse gasses in addition to water vapor.
Carbon dioxide
Chlorofluorocarbons
Methane
Nitrous Oxide
3. How do water vapor and greenhouse gasses contribute to earth’s climate?
Water vapor absorbs some heat energy and greenhouse gasses retains heat on the Earth's surface, and both combined helps keep the climate in control, except in instances of excess of one kind, such as global warming.
4. What are four sources of carbon dioxide?
Aerobic respiration
Pressure and heat from decaying matter into fossil fuels
Human pollution (technology converting fossil fuels)
Volcanoes, living organisms
5. Name three reservoirs for carbon dioxide in addition to the atmosphere.
Living organisms, bodies of water, and soil
6. What are fossil fuels? How are they made?
Fossil fuels are buried remains of ancient plants and microorganisms transformed(made) through heat and pressure for coal, oil and natural gas.
7. Where do plants get the carbon they need to build sugars?
From the CO2 in the Earth's atmosphere
8. Where do animals get the carbon they need to synthesize ATP?
Eating plants
9. How has the amount of carbon dioxide in the atmosphere changed over the past 100 years? What effect has this had on the planet’s overall climate?
The rate in which it is increasing, has changed drastically, in a negative aspect; the effect is the increase of the Earth's temperature, therefore global warming.
10. What is the difference in the chemical structure between ADP and ATP?
ADP has 2 Phosphorous bases while ATP has 3 bases
11. How does ATP transfer energy to parts of a cell?
Phosphorylation
12. What is the difference between aerobic respiration and anaerobic respiration?
One of the respiration requires Oxygen (aerobic), while the other does not (anaerobic)
13. Where do glycolysis, the citric acid cycle, chemiosmosis, and the light and dark reactions of photosynthesis occur in cells?
Mitochondria or Chloroplast of a eukaryotic cell.
14. What are the final products of glycolysis? (don’t forget the energy carriers)
2 Pyruvic acids, 2 NADH's, and net gain of 2 ATPs
15. What molecule enters the citric acid cycle? (hint: it’s not pyruvic acid)
Acetyl-CoA
16. What are the final products of the citric acid cycle?
3 NADH, 1 FADH2, 1 GTP and 2CO2 per pyruvate
17. Where does the electron transport chain get energy from to move H+ ions across the membrane into the inner membrane space?
When an electron is picked up by a protein/handed off to another, it changes shape, and this facilitates the movment of hydrogen ions from the matrix to the intermembrane space.
18. Why is oxygen needed for aerobic respiration?
The final electron receptor after breaking down glucose is Oxygen (for the H+ ions) to bond to form H2O
19. How is ATP generated via chemiosmosis? (be sure to explain the role of ATP synthase in your answer)
As hydrogen rush along its concentration gradient through ATP synthase, it uses the energy(oxidative
phosphorylation( of to produce ATP. 3ATPs per NADH and 2ATPs per FADH2
20. How many ATP are produced per NADH? Per FADH2?
3ATPs per NADH and 2ATPs per FADH2
21. How many total ATP are produced from a single glucose molecule during glycolysis followed by aerobic respiration?
38
22. What part of proteins can be metabolized for energy?
Amino acids
23. What part of lipids can be metabolized for energy?
Fatty acids and Glycerol
24. What is the purpose of fermentation? What would happen to cells if they were somehow prevented from doing it?
To oxidize the NADH carriers from glycolysis; if they were prevented from doing fermentation, the glycolysis would stop completely
25. What are stomata? What type of cells make them up?
Stomata are pores on the surface of leaves that allow gas exchange (entry for CO2 and release of O2); are made up of guard cells
26. Where does the energy come from for the light-dependent reactions of photosynthesis? Where in chloroplasts do these reactions occur?
Photons of light (mainly the sun); light-dependent reactions occur in the thylakoids
27. How do the energy carrier molecules synthesized during the light-dependent reactions of photosynthesis compare to those synthesized during cellular respiration?
Similar, except the molecule NADPH, rather than NADH.
28. Where in chloroplasts are glucose molecules synthesized? What process is responsible for their synthesis?
Stroma; Calvin cycle
29. Why is water necessary for photosynthesis? Why is carbon dioxide necessary? Why is sunlight necessary?
Water or H2O is required for the replacement of hydrogen ions along the electron transport chain.
Carbon dioxide is the core molecule to convert into sugars.
Sunlight's solar energy is used for chemical energy
30. How are rubisco and oxaloacetate similar?
Rubisco and Oxaloacetate are similar in that they both are catalysts in the beginning of either the Calvin or Kreb cycle
31. What is transpiration?
Water moving out of the plant via stomatal openings
32. Which types of plants are most vulnerable to photorespiration? Why?
C3 plants; prevention of CO2 from entering which causes photosynthesis to decline.
33. Why are C3 plants better adapted to cool, shady environments while C4 plants are better adapted to hot, sunny environments?
At high temperatures, C3 have reduced photosynthesis ands close their stomata to reduce the rate of water lost; C4 carry an extra enzyme which avoids photorespiration and continues to make sugars
34. Why is growth limited in CAM plants?
In CAM plants, the stomata opens only at night, therefore the CO2 that enters can not immediately be used because it requires energy from the sun for photosynthesis.
35. How does deforestation contribute to global warming?
Reduction of plants increase the amount CO2 in the atmosphere, since there will be less plants to take in the CO2
36. What role does the United States play in global warming?
The US is the largest nation contributing to the greenhouse effect
Friday, February 5, 2010
Diseases Associated with Obesity
Type II Diabetes
The pancreas glands secretes insulin and binds to the receptors to allow glucose into cells. In type II diabetes, a person body cells are more resistant to insulin or the pancreas works harder and eventually is prone insulin fatigue resulting in low insulin production; thus, reducing the amount of glucose that enters the cells. The glucose that do not enter the cells build up in the blood stream, leaving high blood glucose levels.
Hypertension
There are many factors leading to hypertension: heredity, diet, smoking, lack of exercise, stress, excessive alcohol and salt. Arterioles allow blood to flow freely and exerts little pressure. When the vessels squeeze, it increases the pressure and when blood is moved throughout the arteries at high pressure, it can damage the walls.
Atherosclerosis
Atherosclerosis is a disease where arteries are clogged by plaque. If someone has hypertension, the artery walls can tear, enabling cholesterol and other debris to enter. The white blood cells or macrophages try to clean up but end up absorbing too much, becoming a cholesterol-filled foam. As time passes, it multiplies and form into a plaque.
Heart Attack
The process of Atherosclerosis forming combined with hypertension causes most problems of a heart attack. The plaque build up from behind artery walls burst, and leaks large clots into the blood stream. The clots flow downstream blocking an artery leading to the heart, resulting in a dead heart muscle.
Stroke
Strokes usually occur to people who have a history of high cholesterol or high blood pressure. One type of stroke that can occur is when blood flow is obstructed towards the brain, incapable of the brain of what they need, the lack of oxygen. Another type of stroke is when a blood vessel ruptures in the brain, clotting and adding pressure on the brain depending on where the cerebral area affected is. Ultimately, brain cells become damaged or die and also have a major impact on the body such as paralysis or memory problems.
The pancreas glands secretes insulin and binds to the receptors to allow glucose into cells. In type II diabetes, a person body cells are more resistant to insulin or the pancreas works harder and eventually is prone insulin fatigue resulting in low insulin production; thus, reducing the amount of glucose that enters the cells. The glucose that do not enter the cells build up in the blood stream, leaving high blood glucose levels.
Hypertension
There are many factors leading to hypertension: heredity, diet, smoking, lack of exercise, stress, excessive alcohol and salt. Arterioles allow blood to flow freely and exerts little pressure. When the vessels squeeze, it increases the pressure and when blood is moved throughout the arteries at high pressure, it can damage the walls.
Atherosclerosis
Atherosclerosis is a disease where arteries are clogged by plaque. If someone has hypertension, the artery walls can tear, enabling cholesterol and other debris to enter. The white blood cells or macrophages try to clean up but end up absorbing too much, becoming a cholesterol-filled foam. As time passes, it multiplies and form into a plaque.
Heart Attack
The process of Atherosclerosis forming combined with hypertension causes most problems of a heart attack. The plaque build up from behind artery walls burst, and leaks large clots into the blood stream. The clots flow downstream blocking an artery leading to the heart, resulting in a dead heart muscle.
Stroke
Strokes usually occur to people who have a history of high cholesterol or high blood pressure. One type of stroke that can occur is when blood flow is obstructed towards the brain, incapable of the brain of what they need, the lack of oxygen. Another type of stroke is when a blood vessel ruptures in the brain, clotting and adding pressure on the brain depending on where the cerebral area affected is. Ultimately, brain cells become damaged or die and also have a major impact on the body such as paralysis or memory problems.
Thursday, February 4, 2010
Enzymes
1: Enzymes are
b. proteins.
2: Which of the following binds to the active site of an enzyme?
c. substrate
3: Which of the following correctly represents the mechanism of enzyme function?
d. E + S -> E-S -> E-P -> E + P
4: An enzyme can only bind one reactant at a time.
b. False
5: An enzyme speeds up a chemical reaction in the cell, but can only be used once.
b. False
b. proteins.
2: Which of the following binds to the active site of an enzyme?
c. substrate
3: Which of the following correctly represents the mechanism of enzyme function?
d. E + S -> E-S -> E-P -> E + P
4: An enzyme can only bind one reactant at a time.
b. False
5: An enzyme speeds up a chemical reaction in the cell, but can only be used once.
b. False
Nutrition & Cells
1. What are the differences between vitamins and minerals?
Vitamins are organic molecules and both water soluble and fat soluble, while minerals are inorganic and only water soluble.
2. What are free radicals? How does the body protect itself from them?
Free radicals are highly reactive molecules that come from either the enviornment or leftover from metabolism and are harmful to DNA. The body protects itself from free radicals by producing anti-oxidants which are gained from whole foods.
3. What are essential amino acids and essential fatty acids?
The amount of amino and fatty acids that the body can produce are limited, therefore the remains amino and fatty acids that the body does not produce must be received from the diet, and those you must get from the diets are called essential amino acids and essential fatty acids.
4. What is hydrogenation? How does it affect the chemical structure of fats?
Hydrogenation is the process of adding hydrogen gas to unsaturated fats under pressure. It affects the chemical structure in how the hydrogen bonds to the carbon atoms such as trans-fats.
5. What is the difference between Bacteria and bacteria?
Lower case 'b' in bacteria is a synonym for the Prokaryotic cells and capital 'B' in Bacteria is a classification of the group within Prokaryotes.
6. Which organelles are found in all cells?
Plasma membrane, DNA, and ribosomes
7. What is a concentration gradient? What role does it play in osmosis? Facilitated diffusion? Active transport?
A concentration gradient is the concentration of molecules between a high and low concentration.
8. Where does cellular respiration occur in prokaryotes and eukaryotes?
Cellular respiration occurs in the plasma membrane of prokaryotic cells and in the mitochondria of eukaryotic cells.
9. What components are found in both prokaryotic cells and eukaryotic cells but have different structural characteristics? Describe these differences.
DNA - prokaryotic cells are linear or circular, contained in the nucleoid; eukaryotic cells are always linear contained in nucleus and are chromatin when relaxed, chromosomes when condensed (super coiled)
Ribosome - 70 in prokaryotic 80 in eukaryotic
10. Where are the following manufactured: proteins? ribosomes? lipids?
Proteins; manufactured in the rough ER
Ribosomes; in the nucleolus
Lipids; in the smooth ER
11. What are the three types of endocytosis? How do they differ from one another?
Phagocytosis - digests solids
Pinocytosis - disgests liquids
Receptor-mediated endocytosis - only form when certain proteins are locked into the receptors
12. Name three cellular components that contain microtubules. Which types of cells do these occur in?
Cytoskeleton, centrioles, and cilia and flagella of eukaryotic cells.
13. What is the endosymbiotic theory?
The concept that mitochondria and chloroplats originated from symbiotic bacteria.
14. What do mitochondria and chloroplasts have in common? How do they differ from one another?
They are both energy producers from the cell; mitochondria uses cellular respiration and chloroplasts uses photosynthesis.
15. What is the differences between lysosomes and peroxisomes?
Lysosomes break down materials ingested by the cell using hydrolytic enzymes. They also remove old cellular components and replace with newer ones.
Peroxisomes are responsible for the creation of hydrogen peroxide within a cell and are used to break down fats into usable molecules, as well as catalyze detoxification reactions in the liver.
16. How does bacterial DNA differ from eukaryotic DNA?
Shape; bacterial DNA are circular and eukaryotic DNA are linear
17. Name two prokaryotic cell components that help bacteria cling to surfaces?
Glycocalyx
Fimbria
Vitamins are organic molecules and both water soluble and fat soluble, while minerals are inorganic and only water soluble.
2. What are free radicals? How does the body protect itself from them?
Free radicals are highly reactive molecules that come from either the enviornment or leftover from metabolism and are harmful to DNA. The body protects itself from free radicals by producing anti-oxidants which are gained from whole foods.
3. What are essential amino acids and essential fatty acids?
The amount of amino and fatty acids that the body can produce are limited, therefore the remains amino and fatty acids that the body does not produce must be received from the diet, and those you must get from the diets are called essential amino acids and essential fatty acids.
4. What is hydrogenation? How does it affect the chemical structure of fats?
Hydrogenation is the process of adding hydrogen gas to unsaturated fats under pressure. It affects the chemical structure in how the hydrogen bonds to the carbon atoms such as trans-fats.
5. What is the difference between Bacteria and bacteria?
Lower case 'b' in bacteria is a synonym for the Prokaryotic cells and capital 'B' in Bacteria is a classification of the group within Prokaryotes.
6. Which organelles are found in all cells?
Plasma membrane, DNA, and ribosomes
7. What is a concentration gradient? What role does it play in osmosis? Facilitated diffusion? Active transport?
A concentration gradient is the concentration of molecules between a high and low concentration.
8. Where does cellular respiration occur in prokaryotes and eukaryotes?
Cellular respiration occurs in the plasma membrane of prokaryotic cells and in the mitochondria of eukaryotic cells.
9. What components are found in both prokaryotic cells and eukaryotic cells but have different structural characteristics? Describe these differences.
DNA - prokaryotic cells are linear or circular, contained in the nucleoid; eukaryotic cells are always linear contained in nucleus and are chromatin when relaxed, chromosomes when condensed (super coiled)
Ribosome - 70 in prokaryotic 80 in eukaryotic
10. Where are the following manufactured: proteins? ribosomes? lipids?
Proteins; manufactured in the rough ER
Ribosomes; in the nucleolus
Lipids; in the smooth ER
11. What are the three types of endocytosis? How do they differ from one another?
Phagocytosis - digests solids
Pinocytosis - disgests liquids
Receptor-mediated endocytosis - only form when certain proteins are locked into the receptors
12. Name three cellular components that contain microtubules. Which types of cells do these occur in?
Cytoskeleton, centrioles, and cilia and flagella of eukaryotic cells.
13. What is the endosymbiotic theory?
The concept that mitochondria and chloroplats originated from symbiotic bacteria.
14. What do mitochondria and chloroplasts have in common? How do they differ from one another?
They are both energy producers from the cell; mitochondria uses cellular respiration and chloroplasts uses photosynthesis.
15. What is the differences between lysosomes and peroxisomes?
Lysosomes break down materials ingested by the cell using hydrolytic enzymes. They also remove old cellular components and replace with newer ones.
Peroxisomes are responsible for the creation of hydrogen peroxide within a cell and are used to break down fats into usable molecules, as well as catalyze detoxification reactions in the liver.
16. How does bacterial DNA differ from eukaryotic DNA?
Shape; bacterial DNA are circular and eukaryotic DNA are linear
17. Name two prokaryotic cell components that help bacteria cling to surfaces?
Glycocalyx
Fimbria
Saturday, January 30, 2010
Biochemistry
1. What is the difference between an endergonic and an exergonic reaction?
In metabolism, exergonic occurs in catabolism and releases energy while endergonic occurs in anabolism and consumes energy.
2. How many protons, electrons, and valence electrons does Na+ have? (the atomic number for sodium is 11)
Protons: 11
Electrons: 10
Valence electrons: 8
3. What is the difference between an ionic bond, a covalent bond, and a hydrogen bond? Which is strongest? Weakest?
Ionic bond is the attraction between two oppositely charged ions, usually between a metal and nonmetal. Covalent bond is the sharing of two elections to form pairs. Hydrogen bond is the bonding of hydrogen to an electronegative atom.
Strongest: Covalent bond
Weakest Hydrogen bond
4. What are the four types of organic macromolecules and which monomers link together to make up each?
The four types of organic macromolecules: polysaccharides, lipids, nucleic acids, polypeptides
Monomers: carbohydrates, fatty acids,nucleotides, amino acids -respectively
5. Which type of bond holds together the monomers that make up the four primary organic macromolecules?
Covalent bonds
6. Which type of bonds hold together two complementary strands of DNA?
Hydrogen bonds
7. Why do phospholipids form micelles in water?
The non-polar ends, which are the tails mix together while the phosphate heads, polar ends, form to come in contact with the surrounding water.
8. What is the difference between a saturated and an unsaturated fatty acid?
Saturated fatty acid has more hydrocarbons linked in the chain, while unsaturated fatty acid have carbon doubled bonded to another carbon, reducing the amount of hydrogen in the chain.
9. Often times science fiction stories make reference to silicon-based life forms as opposed to carbon-based life. Why does this make sense as a plausible possibility for alien life?
In the periodic table, silicon is in the same column as carbon, with the same valence electrons; therefore, they have the ability to bond with many other elements including itself (possible backbone for life).
10. What are the three differences between DNA and RNA?
Adenine pairs with Thymine in DNA, Uracil in RNA
Sugar backbones deoxyribonucleic vs. ribonucleic acid
RNA is one-stranded, DNA is double-stranded
11. What are the five nitrogenous bases that form the eight nucleotides that make up RNA and DNA?
Guanine
Cytosine
Adenine
Thymine
Uracil
12. How do nucleotides fit together to form DNA? (draw it!)
Combination of phosphate and sugar as the backbone in the sequence of phosphate-sugar-phosphate-sugar-phosphate-etc. (ie. the sides of the ladder), and one of the 4 nitrogenous bases (G, C, A, T) connected to a sugar backbone complimentary to their pair of nucleotide (half of the horizontal ladder step).
S = Sugar
(A, T, G, C) = Nitrogenous bases ( Adenine, Thymine, Guanine, Cytosine)
13. What causes proteins to fold into their final shape?
The characteristics of their reactive group
14. What is the difference between a protein’s primary structure, secondary structure, tertiary structure, and quaternary structure?
The shape; linear -> helical/sheet-> 3D
15. What causes the structural shape of receptors to change?
The interaction of the right molecule with the right receptor.
16. What would happen if an enzyme were absent from a cell?
The reaction would still occur, but the reactions would not occur at a useful rate (not enough activation energy).
17. What would happen if a cell had too much of a particular enzyme?
Either the reaction process will speed up or completely shut off.
18. Why are enzymes highly specific for their substrates and receptors highly specific for their ligands?
Each has a unique shape and arrange for the active site so they can bind correctly
19. Based on its name, what do you think proteases do? (Hint: these are also called peptidases)
I think proteases have to be something to do with polypeptides, either breaking down or synthesis.
In metabolism, exergonic occurs in catabolism and releases energy while endergonic occurs in anabolism and consumes energy.
2. How many protons, electrons, and valence electrons does Na+ have? (the atomic number for sodium is 11)
Protons: 11
Electrons: 10
Valence electrons: 8
3. What is the difference between an ionic bond, a covalent bond, and a hydrogen bond? Which is strongest? Weakest?
Ionic bond is the attraction between two oppositely charged ions, usually between a metal and nonmetal. Covalent bond is the sharing of two elections to form pairs. Hydrogen bond is the bonding of hydrogen to an electronegative atom.
Strongest: Covalent bond
Weakest Hydrogen bond
4. What are the four types of organic macromolecules and which monomers link together to make up each?
The four types of organic macromolecules: polysaccharides, lipids, nucleic acids, polypeptides
Monomers: carbohydrates, fatty acids,nucleotides, amino acids -respectively
5. Which type of bond holds together the monomers that make up the four primary organic macromolecules?
Covalent bonds
6. Which type of bonds hold together two complementary strands of DNA?
Hydrogen bonds
7. Why do phospholipids form micelles in water?
The non-polar ends, which are the tails mix together while the phosphate heads, polar ends, form to come in contact with the surrounding water.
8. What is the difference between a saturated and an unsaturated fatty acid?
Saturated fatty acid has more hydrocarbons linked in the chain, while unsaturated fatty acid have carbon doubled bonded to another carbon, reducing the amount of hydrogen in the chain.
9. Often times science fiction stories make reference to silicon-based life forms as opposed to carbon-based life. Why does this make sense as a plausible possibility for alien life?
In the periodic table, silicon is in the same column as carbon, with the same valence electrons; therefore, they have the ability to bond with many other elements including itself (possible backbone for life).
10. What are the three differences between DNA and RNA?
Adenine pairs with Thymine in DNA, Uracil in RNA
Sugar backbones deoxyribonucleic vs. ribonucleic acid
RNA is one-stranded, DNA is double-stranded
11. What are the five nitrogenous bases that form the eight nucleotides that make up RNA and DNA?
Guanine
Cytosine
Adenine
Thymine
Uracil
12. How do nucleotides fit together to form DNA? (draw it!)
Combination of phosphate and sugar as the backbone in the sequence of phosphate-sugar-phosphate-sugar-phosphate-etc. (ie. the sides of the ladder), and one of the 4 nitrogenous bases (G, C, A, T) connected to a sugar backbone complimentary to their pair of nucleotide (half of the horizontal ladder step).
. .
S - A = T - S
. .
P P
. .
S - C = G - S
. .
P P
. .
S - G = C - S
. .
P P
. .
S - T = A - S
. .
P = PhosphateS - A = T - S
. .
P P
. .
S - C = G - S
. .
P P
. .
S - G = C - S
. .
P P
. .
S - T = A - S
. .
S = Sugar
(A, T, G, C) = Nitrogenous bases ( Adenine, Thymine, Guanine, Cytosine)
13. What causes proteins to fold into their final shape?
The characteristics of their reactive group
14. What is the difference between a protein’s primary structure, secondary structure, tertiary structure, and quaternary structure?
The shape; linear -> helical/sheet-> 3D
15. What causes the structural shape of receptors to change?
The interaction of the right molecule with the right receptor.
16. What would happen if an enzyme were absent from a cell?
The reaction would still occur, but the reactions would not occur at a useful rate (not enough activation energy).
17. What would happen if a cell had too much of a particular enzyme?
Either the reaction process will speed up or completely shut off.
18. Why are enzymes highly specific for their substrates and receptors highly specific for their ligands?
Each has a unique shape and arrange for the active site so they can bind correctly
19. Based on its name, what do you think proteases do? (Hint: these are also called peptidases)
I think proteases have to be something to do with polypeptides, either breaking down or synthesis.
Science Article 1
When aging, we all have a tendency to unfortunately recieve potential life-risking conditions, especially towards the crowd of senior citizens. Thus, there were studies to see that if physical activity can provide beneficial statistics on behaviors and the physical beings of a group. The study was conducted variously (both had controlled and random assignments), and tested to see if they got the end result they wanted was. However, the data on some aging conditions may have been different if their sampling size were different. Overall, physical activity showed that it reduced a large number of problems of health, but a small percent still remain.
http://www.sciencedaily.com/releases/2010/01/100125172946.htm
http://www.sciencedaily.com/releases/2010/01/100125172946.htm
About Me
Hi, my name is Eric. I'm a quiet and passive guy, but once I get to know somebody, I can be pretty outgoing type. I'm a first year in college attending both Ventura and Oxnard College and trying to cram my classes together so I can transfer quickly. In academics, I have steady grades, usually average to a couple of A's, mostly B's and one or two C's.
So, why am I taking biology? It's basically for my GE's and I picked biology over the other courses, because when I took it in high school, I thought the subject interesting, but I never got to understand it well, so it's a good chance for me to retake the course. I'm not taking the lab portion, so hopefully I won't be confused. Biology to me is one of those intense reading-the-book courses, however I can never find myself to focus reading, so hopefully I'll pass!
So, why am I taking biology? It's basically for my GE's and I picked biology over the other courses, because when I took it in high school, I thought the subject interesting, but I never got to understand it well, so it's a good chance for me to retake the course. I'm not taking the lab portion, so hopefully I won't be confused. Biology to me is one of those intense reading-the-book courses, however I can never find myself to focus reading, so hopefully I'll pass!
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