Download Exam 3 Review Sheet posted 10/18/12

Exam 3 Review Sheet
AP Biology
USE THIS SHEET AFTER YOU HAVE STUDIED AS A METHOD OF EVALUATING WHAT YOU
STILL NEED TO WORK ON…OR DO WHAT YOU ARE LIKELY TO DO, WHICH IS WHATEVER
YOU WANT. SERIOUSLY, STUDY FIRST AND THEN FLY THROUGH MOST OF THESE.
Exam 3 will cover:
Chapter 3 – ALL
Chapter 4 – ALL
Chapter 5 – Up to Proteins
Make sure you look at ALL the questions in all 3 chapters as well as bold words,
headings and figures, the PowerPoint, and this review sheet.
**I posted a macromolecule review chart online.
CHAPTER 3:
1. Hmm…thinking…
2. Describe the structure of water in as much detail as possible including its
geometry, partial charges, etc…
3. All of waters properties come down to…
4. When one pours salt into water, the salt “dissolves”. Explain what this means on
the atomic level. What does it mean to “dissolve”? Include hydration shell in your
response.
5. If I were to pour oil into water, the two substances do not mix. Explain why on the
molecular level. Why can water dissolve salt, but not oil?
6. What is meant by like dissolves like.
7. How is a water molecule held together? How are water molecules held to each
other?
8. In class we discussed many properties of water. The first was cohesion, which
leads to surface tension, a high specific heat, moderation of temperature,
evaporative cooling, and more. Describe cohesion and these resulting properties in
detail.
9. The second property was adhesion. Adhesion allows water to be the “universal
solvent” and makes water extremely sticky. Describe adhesion on the molecular
level. What type of molecules would be involved in adhesion with water? Explain
how adhesion makes water the universal solvent. Draw a picture of a single sodium
atom surrounded by water to demonstrate adhesion, universal solvent and
dissolving all in one picture. Why is adhesion, like all the other properties, so
important for life on Earth as we know it?
10. Explain the difference between solution, aqueous solution, solvent and solute.
Give an example of an aqueous solution and identify the solvent and solute. Give an
example of a non-aqueous solution and do the same.
11. What is heat on the molecular level? Explain how you heat something up (on the
MOLECULAR LEVEL). Don’t just say I turn on the stove. What is the difference
between heat and temperature?
12. Explain why wood burns and why in order for wood to burn, molecular oxygen
needs to be present. Why does this process generate so much “heat”. Your
explanations need to be specific ones on the molecular level. The reductionist
approach is the only way to understand everything.
13. Explain the importance of water’s high specific heat for life on Earth. What does
it mean that water has a high specific heat?
14. Explain why water has a high heat of vaporization. Why is this important in
terms of evaporative cooling?
15. Explain how evaporative cooling works on the molecular level. Why does water
secreted onto your skin cool your body down if the water you are secreting is as
warm as your body?
16. Explain, on the molecular level, why ice is less dense that water and therefore
floats. Why is this unique property of water so important for life on Earth? What
would happen otherwise? Explain how the freezing of water can crack boulders on
the molecular level?
17. In class we discussed that the water in any aqueous solution is not all in the form
of H2O. A very tiny amount breaks apart into H+ and OH-. Write out this chemical
reaction on paper and explain why this happens. What do we call these ions?
18. Define the term concentration. Go through the powerpoint slides and make sure
you understand the concept of concentration.
19. What does Molarity mean?
20. In terms of numbers of molecules dissolved, how many glucose molecules would
be in 0.5L of a 6M (molar) glucose solution.
21. If I have 250ml of the solution in question 33, how many glucose molecules
would be in the solution I am holding in moles.
22. Be able to explain how to make solutions as shown in the PowerPoint. Here is a
link to some Molarity questions with answers:
http://www.chemteam.info/Solutions/WS-Molarity.html
You do not need to do them all! It is just extra practice if you wish. There are also
practice problems in the book at the end of chapter 3 and on page 53.
23. Logarithms. What does it mean to take the logarithm (log; base 10) of a number
(in words)?
24. What is the Molar concentration of H+ in pure water. What does this mean in
terms of actual numbers of free protons? Show how you would convert this
concentration to pH.
25. What does the pH tell us about a solution? Why don’t we just discuss the
concentration of H+ instead of using pH.
26. What do we think pH stands for?
27. What is the pH of a solution with an [H+] = 10-3?
28. Compare and contrast the terms acidic, basic and neutral. Give examples of
solution of each.
29. Which is more acidic, a solution with an [H+] = 10-4 or a solution with an
[H+] = 10-9? Explain. What would the pH of these solutions be?
30. Discuss the relationship between the [H+] and the pH in terms of when one goes
up, what happens to the other? Explain why this relationship exists.
31. As the H+ concentration changes 10-fold (10X higher or 10X low [H+]), what
happens to the pH?
32. If the [H+] of one solution is 10,000X times higher than a second solution that
has a pH of 8, what is the pH of the first solution?
33. There are two solutions in front of you. One has a pH 9 and the other a pH 13.
First, are these solutions basic, acidic or neutral? Second, how much higher or lower
is the [H+] of the pH13 solution compared to the pH9 solution?
34. Compare and contrast an acid to a base. Make sure to define each. Give an
example of an acid and a base.
35. Sodium hydroxide (Na+OH-) is considered a very strong base. Explain how, on
the molecular level, this compound acts like a base. (How does it remove free
protons from a solution?)
36. If I had a solution with a measured pH of 3, what would I need to do in order to
change the pH to 7? What if I wanted to change it to 1?
37. If you add acid to a solution, does it become acidic or basic? Explain.
38. If I give you a solution, blue litmus paper and red litmus paper, explain how you
would determine if this solution is acidic or basic.
39. Which would give you a more accurate pH value, red litmus paper, blue litmus
paper or hydrion paper? Explain.
40. Your fish looks very sick and you wonder it the pH is off. They typically prefer to
be in a pH below 8. You have with you a bottle of phenolphthalein. Explain how you
would determine if you have a pH problem.
41. Swimming pools should be kept at a pH around neutral. You are going to have a
huge pool party tomorrow night and need to make sure that the pH is correct. You
have with you a bottle of bromothymol blue. Explain how you would use the
bromothymol blue to determine the pH of the pool. What would you expect to find if
the pool has a pH of 4? of 7? of 10?
42. You measured the pH of the pool and found it to be 12!! What do you need to do?
43. You inform Dr. T of your pool problem and he suggests adding a buffer. What is a
buffer and how would it help? Explain exactly how a buffer works in terms of le
Chatlier’s Principle.
44. Are buffers permanent? Will they force the pH to never change? Explain.
45. In class we said that the normal pH of rain is around 5.5. Explain why it is acidic and
not neutral.
46. Explain acid precipitation (why is occurs) and why it is a problem to organisms on
the molecular level.
47. Define the calorie and the Joule.
48. Approximately how fast do molecules move at room/body temperature.
49. Explain the significance of the hydronium ion.
50. Describe van der Waals interactions. Why do they occur in terms of electron
positions? Between what types of molecules do van der Waals occur? These interactions
are the weakest relative to the bonds we have spoken about. When will they be
significant?
51. Describe how transpiration works and be sure to discuss adhesion, cohesion, solar
energy, stomates, xylem and H-bonding.
CHAPTERS 4 and PART OF 5:
1. Explain on the molecular level what happens to a crystal composed of glucose when
you throw it in water (don’t just say that it dissolves).
2. Compare and contrast organic compounds and hydrocarbons. Why are all
hydrocarbons organic, but not all organic molecules are hydrocarbons?
3. Be able to identify/circle the carbon skeleton of a hydrocarbon.
4. Compare and contrast structural, geometric and enantiomeric isomers. Be able to draw
examples of each.
5. Explain how you can determine by looking at a molecule if it will have an
enantiomeric isomer in terms of an asymmetric carbon.
6. We said the all amino acids are “L” and all sugar are “D”. What does this refer to?
6.5. Make sure you can draw/identify an L-amino acid
7. What is meant by “cis” and “trans” in terms of geometric isomers? Draw a pair of cis
and trans isomers. Why is the double bond necessary? What property makes it necessary?
8. Be able to convert a skeletal formula into the corresponding structural formula.
9. Be able to draw a small molecule like methane and ethane three-dimensionally using
the wedge-and-dash projection learned in class.
10. Compare tetrahedral to planar molecular shapes and draw examples of each. Be able
to explain why each forms.
11. Describe the formation of early Earth in terms of the Great Bombardment,
atmosphere formation, ocean formation, etc…
12. How are elements larger than lithium formed? Where did the carbon, oxygen,
nitrogen, phosphorus, sulfur that make up you come from since universe began with just
hydrogen, helium and perhaps some lithium?
13. Describe the Miller-Urey experiment and explain the results/conclusions.
14. Define teratogen and give an example.
15. Know the functional group table in the textbook. Be able to draw the functional
groups.
16. Identify the functional groups in the molecule below (there are three):
17. I can ask you a questions similar to: draw an organic molecule that contain a
sulfhydryl group and is acidic.
18. Compare and contrast aldehydes to ketones. Why are these NOT considered
functional groups, but rather a type of compound? What is the functional group found in
each of these? Which class of macromolecule contains both types of compounds?
19. Which types of compounds usually end in –ol? What functional group is involved?
20. Describe in detail why carboxylic acids are considered acids (You will need to
discuss electronegativity differences between atoms). What class of macromolecules
contain this functional group?
21. Compare and contrast the carbonyl to the carboxyl group. Which two functional
groups add to be a carboxyl? Reminder: if the group is a ccarboxy, it is not also a
carbonyl and a hydroxyl (You cannot circle the C=O in question 6 and say it’s a
carbonyl. Why?)
22. Compare hydrophobic and hydrophilic. What makes something hydrophobic or
hydrophilic? Describe how this works on the MOLECULAR LEVEL. Don’t just say
nonpolar or polar… Speak in terms of electronegativity and the electromagnetic force.
23. What is meant by a macromolecule? List each and its general function in organisms.
24. Compare monomers to polymers. Know the terms dimer, trimer, tetramer, pentamer,
etc…
25. Draw ATP as discussed in class and explain why this molecule is like a loaded gun.
What is the role (function) of ATP in the cell? There are two obvious roles.
26. Explain the reactions in detail used to build (anabolic, synthesis) and break (catabolic,
digest) the macromolecules. – you should be able to draw these using spheres.
27. Compare and contrast monosaccharides, disaccharides and polysaccharides. In
addition, be able to give examples of each. All together these are called what?
28. Be able to draw a chart indicating the various combinations of monosaccharides and
the respective disaccharide that forms (maltose, sucrose, lactose).
29. Be able to draw the ring structure of glucose as well as any glucose disaccharide like
maltose.
30. Describe how two glucose molecules join together and the type of linkage that is
formed (Figure 3.5). You should be able to draw this chemical reaction.
31. Describe the difference between alpha and beta glucose, and explain why these two
different forms exist.
32. What does the word “carbohydrate” mean, literally and why do we use this word to
describe the kinds of molecules that we do?
33. Discuss what is meant by the empirical formula [CH2O]n
34. Look at the structure of ANY monosaccharide. What functional group is attached to
every carbon except one? What functional group is that other carbon a part of?
35. If I told you to draw C6H12O6, what would your response be to me…
36. Make sure you can identify different glycosidic linkages when looking at
disaccharides. Ex. Beta 1,4 vs alpha 1,6 etc…
37. Compare and contrast the three polysaccharides discussed in class. Include their
structures, why they have the same or different structures, where they are found in the
world, their functions in organisms, how structure relates to function in this case, etc…
38. Cellulose is considered “fiber”. Like when the commercials on TV say that Cheerios
is high in “fiber”. What is fiber? Why is cellulose called or at least part of what we call
“fiber”? What is the benefit of insoluble fiber if we cannot digest it?
39. Why are most animals not able to hydrolyze cellulose, but can hydrolyze glycogen
and starch when all three are just polymers of glucose? How are some animals able to
hydrolyze cellulose?
40. Explain what happens to plant starch when you eat it (like if you eat a potato).
41. What is the monomer of the protein, how many are there, what makes each of these
different, how are they similar and how are they grouped (the three groups)? Can you
draw any two of them yet and connect them via dehydration synthesis (condensation
reaction)?...you need to be able to do this.
42. Where does the “amino acid” get its name from?
43. Why do I feel that proteins are the most important class of macromolecules (they are
all important of course)?
44. Compare an amino acid, dipeptide, polypeptide, and protein.
45. Describe how a dipeptide is formed (Figure 3.13). What do we call the bond that links
them? How is this analogous to what happens with carbohydrates?
46. Describe the three groups of amino acids. Which group has the acidic and basic ones?
47. What determines the structure of a particular protein? Explain why. Of course, the
structure then determines the…
48. Explain why a change in the DNA might lead to problems.
48.5 Know sickle-cell anemia example really well. You should be able to use this
example to convince to me that mutations can be both positive and negative. Really well!
49. Describe in general terms what happens to a polypeptide (or any polymer for that
matter) when you eat it. What happens to it, what do you do with it, etc…
50. Describe the four levels of protein structure. I could ask another 15 questions about
each level… Know all the details we went over in class like when the side chains come
into play or when only the backbone is involved, hydrophobic vs hydrophilic side chains,
where different types of side chains are located in proteins typically, etc…
50.5. All alpha helices are right or left handed? This is because they are made with…
51. Explain why these levels of structure have little to do with actual protein folding in
the cytoplasm.
52. Explain, starting with a gene, how a protein is formed. Make sure you include items
like mRNA, tRNA, ribosome, nuclear pore, RNA polymerase, amino acids, nucleus,
etc… Basically, describe the central dogma.
53. Be able to identify the various secondary structure elements in a protein and circle
them if presented with a ribbon diagram.
54. Explain how a ribbon diagram is generated. What are you looking at when you view a
ribbon diagram of a protein – (these are the colorful diagrams with sheets shown as
arrows and helices are cartoon-like spirals)?
55. Compare and contrast a polypeptide to a protein. When are they the same and when
would they be different?
56. What is meant by a subunit in a protein?
57. Explain what is meant by denature and renature. How and why do proteins denature?
You must be very specific. You cannot just say a lower pH than the protein evolved in
will cause it to denature…the question is WHY.
58. Know the functions of proteins. Know examples like hemoglobin, myosin, insulin,
insulin receptor, ATP synthase, photosystem II, antibodies, HIV protease, etc… and
under what category they would fall.
59. How small is a protein relative to the size of a cell? (use the analogy) How many
hemoglobin proteins are packed into a single red blood cell? How many red blood cells
do you have on average? How many oxygens can your blood carry if it were completely
saturated with oxygen?
60. Why are some people considered to be lactose intolerant? What does this mean and
why is it a problem?
61. Are glycogen, starch and cellulose the only three polysaccharides found in
organisms? Explain.
62. What is the fate of glucose? Basically, what do organisms use glucose monomers for?
Why do we store them? Where do humans store them?
63. If there is too much glucose in your blood, how does your body handle this? Where
does it end up? Where might this surge in glucose have come from?
64. For every polymer we eat (disaccharides, polysaccharides, polypeptides, etc…), we
need to have a ___________________ somewhere in our digestive tract to hydrolyze it.
This may seem obvious, but we eat cells (unless you are eating processed food, which
case the cells have already been destroyed and broken apart) of other organisms. There
we eat macromolecule or at least polymers for the most part. We need to hydrolyze them.
Why? Why not just keep them together?
65. Know who Linus Pauling was and what he did…
66. Describe structure of chitin and where it is found in nature.
67. Identify kingdoms with organisms that have cell walls and the composition of these
walls in each.
68. Describe what 3.4 and n+4 mean in terms of alpha helices.
I am stopping here…so much time, and so little to do. Scratch that, reverse it.