Download Exam 3 Review Sheet 11/8/10

Exam 3 Review Sheet
Honors Biology
USE THIS SHEET AFTER YOU HAVE STUDIED AS A
METHOD OF EVALUATING WHAT YOU STILL NEED TO
WORK ON.
Exam 3 will cover:
ALL of Chapter 3
Chapter 3 PowerPoint
Macromolecule chart (download from notes section)
(STOP HERE…have you studied yet? If yes, continue… If no, GO STUDY FIRST! DO
NOT USE THIS TO STUDY!) These are questions you should be able to answer after
studying.
1. The Exam 2 and Quiz 6 Review sheet.
2. Download and print out the COMPLETE macromolecule table on the website. Use this
chart as a study tool.
3. Explain what happens to the polymers we are constantly eating. Where did most the
monomers that make up these polymers ultimately come from? (This will require some
logical thinking)
4. How would you define a lipid.
5. How are lipids chemically different from the other three classes of macromolecules?
6. Identify the four types of lipids discussed in class. Be able to draw each type as we
discussed in class. You will be required to draw one of the macromolecule classes on the
exam. Make you can connect everything by dehydration synthesis to make dimers, etc…
7. How do unsaturated and saturated fatty acids differ structurally? How does this change
how they behave relative to each other?
8. Compare a saturated to an unsaturated TRIGLYCERIDE (This is different than
comparing a saturated and unsaturated fatty acid).
9. Where does one find unsaturated fats in nature? What about saturated fats?
10. What does the term “hydrogenated vegetable oil” refer to? Give an example of
hydrogenated vegetable oil that you might find in the supermarket.
11. Describe why saturated fats tend to be solid at room temperature while unsaturated
fats tend to be liquid.
12. Identifty the functions of triglycerides in nature. Where are they found (what type of
cell and what location in humans)? What is the name we give the fat cells in these two
locations. Which is more prevalent in males? Females? What are the “fruity” terms we
use to describe the resulting human figures?
13. Compare and contrast a phospholipid to a triglyceride (What is similar and what is
different?).
14. Describe the function of phospholipids in nature.
15. Why do phospholipids tend to always have one kinked fatty acid (one kinked tail)?
16. Define the term amphiphilic.
17. How does the term amphiphillic relate to phospholipids and why is this an important
property of these molecules?
18. Be able to draw the two structures discussed in class that will result if you take moles
of phospholipids and add them to water. Know the names of the two resulting structures.
Which of these structures would be similar to a cell membrane?
19. Describe the general function of cell membranes in the cell.
20. Describe the structure and function of waxes in nature. Identify at least two places
where you would find them, one in plants and one in animals.
21. Describe the general structure of a steroid and give at least four examples in humans.
22. One example of a steroid is cholesterol. Describe the two functions of cholesterol in
our cells that we spoke about in class, and indicate how the structure of this molecule
determines its function.
23. What is a hormone? Which class of macromolecule and which subclass of a second
class can act as hormones in the body?
24. We learned that steroids can act as hormones (so now you know that protein
[polypeptides] and steroids can act as hormones (signaling molecules that allow cells to
“talk” to each other that are not typically located near each other) – this is the answer to
question 23. Indicate the three types of steroid hormones we discussed in class and
describe their function in the body.
25. How is cholesterol linked to the sex hormones?
26. Read section 3.10 in the book. Expect a question.
27. Describe Chargaff’s experiments and why the results were critical in determining the
three-dimensional structure of DNA.
28. Chargaff used a technique known in general terms as paper chromatography.
Describe how to do paper chromatography in general. For example, if I gave you a
solution containing a mixture of various food colorings, how might you separate them?
Explain why paper chromatography works.
29. Describe the three-dimensional structure of DNA.
30. Note the base pairing rules of DNA…a purine always pairs with a pyrimidine. Why
do you think life evolved this way? (think structurally)
31. Why is it important that the base pairs of DNA be held together by hydrogen bonds as
opposed to using covalent or ionic bonds?
32. One of the DNA strands is typically called the “complementary” strand. Why do you
think this strand was given this name?
33. What do I mean when I say that the strands of DNA are anti-parallel?
34. Be able to label the ends of the DNA strands (5’ and 3’) and be able to explain why
the ends are given these names.
41. Describe the function of DNA in organisms.
42. How is the DNA molecule able to store information? What part of the molecule do
we call the “paper” and what part do we call the “ink”?
43. How does the structure of DNA compare to that of RNA? (Three major differences)
44. Identify the three types of RNA discussed in class and give their function.
45. (This will be a question) Describe how the cell is able to make polypeptides using
the information that is encoded in the DNA. Be able to describe it both using the analogy
and using the actual terms. Be sure to include the following words: DNA, mRNA, tRNA,
rRNA, protein, RNA polymerase (why is this enzyme called RNA polymerase?),
ribosome, polypeptide, amino acids, library, paper, transcribe, translate, nuclear pores,
nuclear membrane, guards. You should be able to make a sketch of this process.
46. The process described above is known as “The Central Dogma” of molecular
biology. What does this mean? (google it)
47. Why is the nucleus NOT NOT NOT (just incase you didn’t see the first NOT) the
control center/brain of the cell?
48. (You will see this question for sure) We discussed the RNA world hypothesis in
class. Describe why it is logical to hypothesize that RNA was used by the most primitive
of cells before the evolution of DNA and protein. What specific evidence do we have that
supports this? (I discussed two major pieces of observational evidence) Why couldn’t
protein have come first or DNA have come first?
49. Why do you think protein and DNA exist today? Why aren’t organisms still solely
based on RNA? Use the term natural selection in your answer to these questions.
50. What is the name given to a stretch of DNA that codes (stores the information for) for
a polypeptide?
51. You have already explained in question 31 how a protein is made, but how are
tRNA’s and rRNA’s made?
52. Describe the structure of the ribosome. What is it made of?
53. Where do the amino acids that out cells use to build polypeptides come from? Yes, I
know they are in the cytoplasm, but before that…
54. List each macromolecule class and identify where you would find each in a cell. The
next step is going to be to put these molecules together and build a cell. You should have
the basic location and function down before we start getting into details.
55. How many pieces of DNA (“books”) are found in a human nucleus? If you attached
all those pieces end to end, how long would the DNA be? What do we call each piece
(“book”)? How many unique books are there? Explain.
56. Describe the Madison square garden analogy and be sure to include every
macromolecule class (the rope, the straight pin (a phospholipid), the baseball, the head of
a pin (a glucose molecule))
57. Explain why hydrophilic molecules like proteins, amino acids, carbohydrates, nucleic
acids, etc… are NOT able to move through a plasma membrane, while small hydrophobic
molecules can.
(Why do you think large hydrophobic molecules have trouble crossing?)
58. Why do think amino acid based hormones require a cell surface receptor protein to
tell the cell what to do (talk to the cell), while steroid hormones typically have protein
receptors inside the cell, in the cytoplasm?
59. Compare a phospholipid bilayer to a phospholipid monolayer. Which would make up
a cell membrane and why is this a logical choice (why would the other not work as a cell
membrane?).