Download (DOCX, Unknown)

1. How does the polarity of water contribute to its ability to dissolve so many
substances?
a. Because it is polar, water’s oppositely charged ends are attracted
to positively and negatively charged ions and molecules. Water
molecules form a hydration shell around oppositely charged
particles.
b. Natural water has a pH of approximately 5.6, which is slightly acidic.
Acids can dissolve more substances than bases.
c. Because it is polar, water forms ionic bonds with the ions in
substances such as NaCl (salt).
d. Because it is polar, water is able to interact with and dissolve
hydrophobic substances.
e. Water’s polarity allows it to form covalent bonds with many
substances.
2. Compared with 31P, the radioactive isotope 32P has
a. A different atomic number
b. One more neutron
c. One more electron
d. A different charge
e. One more proton
3. Radioactive isotopes are useful in scientific research because
a. They are not readily incorporated into biological reactions
b. They decay spontaneously and give off energy and subatomic
particles
c. They are difficult to detect in small amounts, but living cells cannot
distinguish them from the corresponding stable isotopes
d. They can be used as tracers to follow particular atoms and
molecules through metabolic pathways
4. Which of the following are pyrimidines found in the nucleic acid DNA?
a. Uracil and guanine
b. Adenine and guanine
c. Thymine and adenine
d. Thymine and cytosine
e. Guanine and cytosine
5. What is the role of Van der Waals interactions in biological molecules?
a. VDW are strong bonds that play a major structural role in holding
proteins together
b. VDW are too weak to be significant
c. VDW are only important in water
d. Although they are weak, VDW involve the sharing of electrons
e. Although they are weak, VDW help to reinforce threedimensional shapes of large molecules
6. The partial charges on a water molecule occur because of
a. The high electronegativity of hydrogen
b. Covalent bonding
c. Widespread ionization
d. The unequal sharing of electrons between the hydrogen and the
oxygen atoms of a water molecule
e. The achievement of a stable configuration by one atom of a bond but
not by the other partner
7. Which of these is found in all amino acids?
a. –COOH
b. –OH
c. –COH
d. –NH2
e. both –COOH and –NH2
8. A molecule that has all nonpolar covalent bonds would be
a. hydrophilic
b. acidic
c. ionic
d. basic (alkaline)
e. hydrophobic
9. We can be sure that a mole of table sugar and a mole of vitamin C are equal in
their
a. Mass in grams
b. Volume
c. Number of atoms
d. Mass in daltons
e. Number of molecules
10. Most of water’s unique features (for example, its versatility as a solvent,
ability to moderate temperature, and cohesive behavior) result from the fact
that
a. Oxygen attracts electrons more than hydrogen does
b. Oxygen has two unfilled electron shells
c. Oxygen has only one stable isotope, but hydrogen has three
d. Hydrogen is the only element without any neutrons
e. More than one of the above is correct
11. Adhesion is best described as
a. The clinging of one substance to another substance
b. A property of water that helps moderate Earth’s temperature
c. The process by which a crystalline lattice forms
d. The process that contributes to the transport of water and dissolved
nutrients in plants by causing water molecules to tug on other water
molecules
e. None of the above
12. Nutritionally, saturated tracylglycerols are considered to be less healthful
than unsaturated triaclyglycerols. What is the difference between them?
a. Saturated triacylglycerols are fats; unsaturated triacylglycerols are
carbohydrates
b. Saturated triacylglycerols are liquid at room temperature
c. Saturated triacylglycerols have more double bonds than unsaturated
triacylglycerols
d. Saturated triacylglycerols have more hydrogen atoms than
unsaturated triacylglycerols
13. Phosphorus-32 (radioactive) has _______ than phosphorus-35 (normal).
a. 3 fewer neutrons
b. 3 more neutrons
c. 3 fewer protons
d. 3 more protons
e. 3 more atoms
14. Enzyme molecules require a specific shape to perform their catalytic
function. Which of the following might alter the shape of an enzymatic
protein?
a. Denaturing the protein
b. Heating the protein
c. Mixing in a chemical that removes hydrogen bonds
d. A change in salt concentrations or pH
e. All of the above
15. Adding acid tends to ______ of a solution
a. Decrease the hydrogen ion concentration and lower the pH
b. Increase the hydrogen ion concentration and raise the pH
c. Decrease the hydrogen ion concentration and raise the pH
d. Increase the hydrogen ion concentration and lower the pH
16. Fats store more energy than carbohydrates
a. True
b. False
17. Which of these is a hydroxyl group?
a. –NH2
b. –COH
c. –SH
d. –OH
e. None of the above
18. The phenomenon responsible for maintaining the upward movement of
water through a vessel is (This is a poorly worded question and I realized
that there is more than one answer so I apologize for that)
a. Adhesion
b. Cohesion
c. Surface tension
d. Evaporation
19. A polar covalent bond is a bond that
a. Shares electrons equally between atoms
b. Ionizes
c. Has shared electrons pulled closer to the more electronegative
atom
d. Is found only in molecules containing oxygen
20. We can represent atoms by listing the number of protons, neutrons, and
electrons- for example, 2p+, 2n0, 2e- for helium. Which of the following
represents the 18O isotope for oxygen?
a. 8p+, 10n0, 8eb. 6p+, 8n0, 6ec. 9p+, 9n0, 9ed. 10p+, 8n0, 9e21. Hydrophobic molecules are _______ water
a. Polarized by
b. Absorbed by
c. Attracted to
d. Neutralized by
e. Repelled by
22. When one or more pairs of valence electrons are shared by two neutral
atoms, what type of bond is formed?
a. Neutral bond
b. Covalent bond
c. Hydrogen bond
d. Electronegative bond
e. Ionic bond
23. Which of the following is the best example of an ecosystem?
a. All of the environments on Earth that are inhabited by life
b. All individual species in a population
c. All of the banana slugs in a coniferous forest in Oregon
d. All living and nonliving things that interact in a certain area
24. A neutral atom has a mass number of 32 and an atomic number of 16. How
many neutrons does this atom have? How many covalent bonds can it form?
(This is worded weirdly and I also didn’t really give a correct answer for this.
It should be 16 neutrons; 2 bonds).
a. 16 neutrons; 4 bonds
b. 8 neutrons; 2 bonds 1
c. 6 neutrons; 2 bonds
d. 32 neutrons; 4 bonds
25. Which property of water best describes its ability regulate temperatures?
a. Cohesion
b. High heat of fusion
c. Bent molecular shape
d. High specific heat capacity
26. An interesting organic chemistry reaction involves a compound whose
nitrogen atom loses an electron to a chlorine atom, resulting in charges on
both atoms. What type of bond has formed?
a. Double covalent
b. Ionic
c. Polar covalent
d. Nonpolar covalent
27. Which of the following statements about phospholipids is false?
a. They contain both saturated and unsaturated fatty acid tails
b. They are found in plant cell membranes
c. They comprise a glycerol backbone, a phosphate group, and
three fatty acid tails
d. There is a hydrophobic end and a hydrophilic end
28. Sodium has 11 electrons, 11 protons, and 11 neutrons, what is the atomic
number and atomic mass of Sodium?
a. Atomic number: 11; atomic mass: 11
b. Atomic number: 11; atomic mass: 33
c. Atomic number: 22; atomic mass: 22
d. Atomic number: 11; atomic mass: 22
e. Atomic number: 22; atomic mass: 11
29. Which of the following about covalent bonds is NOT true?
a. Atoms share valence electrons
b. Covalent bonds are very weak
c. Covalent bonds are very strong
d. Both a and b
30. How many bonds can water molecules make using Hydrogen bonding?
a. 1
b. 2
c. 3
d. 4
e. none of the above
31. What is the molecular mass of C3H6O3? (molecular mass of Carbon is 12,
Hydrogen is 1, Oxygen is 16).
a. 180
b. 12
c. 90
d. 120
e. 210
32. Which of the following macromolecules is not a true polymer?
a. Nucleic acids
b. Lipids
c. Carbohydrates
d. Proteins
33. Which of the following are the building blocks for carbohydrates?
a. Amino acids
b. Monosaccharides
c. Phospholipids
d. Starch
34. Lipids are hydrophobic molecues
a. True
b. False
35. Which of the following is NOT a functional group?
a. Hydroxyl
b. Phosphate
c. Carbon
d. Methyl
e. Amino
36. Which of the following is not attached to the alpha-carbon in an amino acid?
a. A hydrogen
b. An R-group (side chain)
c. A carbonyl group
d. An amino group
37. Proteins have different levels of structure. The secondary structure is caused
by which of the following:
a. Interactions between different polypeptides
b. Covalent interactions in the R group of each amino acids
c. Hydrogen bonds between the backbone
d. The shape of the amino acid
38. If I threw a blob of protein in a cup with an extremely acidic solution, what
would happen to the native structure of the protein?
a. It would form two blobs of protein
b. It would become a salt
c. It would still remain a blob of protein
d. It would denature
39. Which of the following is not a pyrimidine?
a. Cytosine
b. Guanine
c. Thymine
d. Adenine
e. Uracil
f. Both a and d
g. Both b and d
h. Both c and d
i. Both b and e
40. How are nucleotides joined together?
a. Glycosidic linkage
b. Phosphodiester linkage
c. Sugar linkage
d. Lipid bilayer linkage
e. None of the above