AP Bio Unit 2 Organic Chemistry

Mastering Biology Qs

The complexity and variety of organic molecules is due to ___.

1. the chemical versatility of carbon atoms

2. their interaction with water

3. the diverse bonding patterns of nitrogen

4. the variety of rare elements in organic molecules

1. the chemical versatility of carbon atoms

Which of the following is true of carbon?

1. it forms only polar molecules

2. it can form both polar and nonpolar bonds

3. it is highly electronegative

4. it can form a maximum of three covalent bonds with other elements

2. it can form both polar and nonpolar bonds

how many electron pairs does carbon share to complete its valence shell

1. 2 electron pairs

2. 3 electron pairs

3. 4 electron pairs

4. 8 electron pairs

3. 4 electron pairs

Research indicates that ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; that is, molecules that _____.

1. have identical chemical formulas but differ in the branching of their carbon skeletons

2. differ in the arrangement of atoms around their double bonds

3. are mirror images of each other

4. differ in the location of their double bonds

3. are mirror images of each other

The figure above shows the structures of glucose and fructose. These two molecules differ in the _____.

1. arrangement of carbon, hydrogen, and oxygen atoms

2. types of carbon, hydrogen, and oxygen atoms

3. number of oxygen atoms joined to carbon atoms by double covalent bonds

4. number of carbon, hydrogen, and oxygen atoms

1. arrangement of carbon, hydrogen, and oxygen atoms

Which of the following molecules is polar?
C₃H₇OH C₂H₅COOH

1. Neither C₂H₅COOH or C₃H₇OH is polar.

2. C₂H₅COOH is polar, but C₃H₇OH is not polar.

3. C₃H₇OH is not polar, but C₃H₇OH is polar.

4. C₃H₇OH and C₂H₅COOH are both polar molecules.

4. C₃H₇OH and C₂H₅COOH are both polar molecules.

Which molecule shown above would have a positive charge in a cell?

1. A

2. B

3. C

4. D

4. D

How many molecules of water are used to completely hydrolyze a polymer that is 11 monomers long?

1. 9 molecules of water

2. 12 molecules of water

3. 11 molecules of water

4. 10 molecules of water

4. 10 molecules of water

What does the term insoluble fiber refer to on food packages?

1. amylopectin

2. starch

3. cellulose

4. polypeptide

3. cellulose

A glycosidic linkage is analogous to which of the following in proteins?

1. a disulfide bond

2. a β-pleated sheet

3. an amino group

4. a peptide bond

4. a peptide bond

Lipids _____.

1. contain less energy than proteins and carbohydrates

2. are insoluble in water

3. are made from glycerol, fatty acids, and nitrogen

4. are made by dehydration reactions

2. are insoluable in water

Saturated fatty acids _____.

1. have double bonds between carbon atoms of the fatty acids

2. are usually liquid at room temperature

3. are usually produced by plants

4. are the principal molecules in lard and butter

4. are the principal molecules in lard and butter

What component of amino acid structure varies among different amino acids?

1. the glycerol molecule that forms the backbone of the amino acid

2. the long carbon-hydrogen tails of the molecule

3. the components of the R-group

4. the presence of a central C atom

3. the components of the R-group

Use the following information when answering the corresponding question.

Rhodopsins are light-sensitive molecules composed of a protein (opsin) and retinal (derivative of vitamin A). Opsin is a membrane protein with several α-helical segments that loop back and forth through the plasma membrane. There are two classes of rhodopsins. According to Oded Beje, one class has relatively slow dynamics (a photocycle of approximately 0.5 second) and is well suited for light detection. The second class has faster dynamics (a photocycle of approximately 0.02 seconds) and is well suited for chemiosmosis: pumping of protons or chloride ions across cell membranes. Oded Beje was the first, in September 2000, to report on a rhodopsin (proteorhodopsin) found in the domain Bacteria. [SOURCE: O. Beje et al., Science 289 (2000): 1902.]


Proteorhodopsin consists of a single polypeptide chain. What is the highest level of structure found in this protein?

1. primary

2. secondary

3. tertiary

4. quaternary

3. tertiary

What is the term used for a protein molecule that assists in the proper folding of other proteins?

1. denaturing protein

2. tertiary protein

3. chaperonin

4. renaturing protein

3. chaperonin

Nucleic acids are polymers made up of which of the following monomers?

1. nucleotides

2. nitrogenous bases

3. amino acids

4. sugars

1. nucleotides

Which of the following includes all of the pyrimidines found in RNA and DNA?

1. cytosine, uracil, and guanine

2. cytosine, uracil, and thymine

3. cytosine and thymine

4. cytosine and uracil

2. cytosine, uracil, and thymine

One of the primary functions of RNA molecules is to _____.

1. act as a pattern or blueprint to form DNA

2. function in the synthesis of proteins

3. make a copy of itself, thus ensuring genetic continuity

4. transmit genetic information to offspring

2. function in the synthesis of proteins

Which of the following descriptions best fits the class of molecules known as nucleotides?

1. a nitrogenous base, a phosphate group, and a sugar

2. a nitrogenous base and a sugar

3. a nitrogenous base and a phosphate group

4. a sugar and a purine or pyrimidine

1. a nitrogenous base, a phosphate group, and a sugar

The following question are based on the 15 molecules illustrated in the accompanying figure. Each molecule may be used once, more than once, or not at all.

1. Molecule 1

2. Molecule 14

3. Molecule 5

4. Molecule 12

3. Molecule 5

Which of the functional groups shown above is most likely to gain a proton and become positively charged?

1. The amino group is most likely to gain a proton.

2. The hydroxyl group is most likely to gain a proton.

3. The carboxyl group is most likely to gain a proton.

1. The amino group is most likely to gain a proton.

How do isomers differ from one another?

1. Isomers differ in the arrangement or bonding of atoms.

2. Isomers differ in charge.

3. Isomers differ in molecular formulas.

1. Isomers differ in the arrangement or bonding of atoms.

Which statement about isomers is correct?

1. Enantiomers differ in biological activity.

2. Structural isomers differ in the position of double bonds within the molecule.

3. Cis-trans isomers are mirror image isomers.

1. Enantiomers differ in biological activity.

Which of the following statements about functional groups is TRUE?

1. DNA and RNA are functional groups.

2. Lipids and proteins are functional groups.

3. Amino and carboxyl are functional groups

3. Amino and carboxyl are functional groups

Which statement about a methyl functional group is correct?

1. A methyl group is polar.

2. A methyl group may be negatively charged.

3. A methyl group consists of a carbon bonded to three hydrogen atoms.

3. A methyl group consists of a carbon bonded to three hydrogen atoms.

Which molecule is a nucleotide

1. the amino acid glycine

2. deoxyribose

3. ATP

3. ATP

These figures show the four levels of protein structure: primary, secondary, tertiary, and quaternary structure. Which level of protein structure is characteristic of some, but not all, proteins?

1. Secondary level of protein structure

2. Quaternary level of protein structure

3. Tertiary level of protein structure

2. Quaternary level of protein structure

There are four levels of protein structure. These figures show primary, secondary, tertiary, and quaternary protein structure. Which level(s) of protein structure may be stabilized by covalent bonds?

1. Primary, tertiary and quaternary levels of protein structure

2. Secondary level of protein structure

3. None of the levels of protein structure is stabilized by covalent bonds.

1. Primary, tertiary and quaternary levels of protein structure

What structural difference accounts for the functional differences between starch and cellulose?

1. Starch and cellulose differ in the glycosidic linkages between their glucose monomers.

2. Starch is a polymer of glucose, whereas cellulose is a polymer of fructose.

3. Starch can be digested by animal enzymes, whereas cellulose cannot.

1. Starch and cellulose differ in the glycosidic linkages between their glucose monomers.

Which feature of large biological molecules explains their great diversity?

1. The many ways that monomers of each class of biological molecule can be combined into polymers

2. The many classes of large biological molecules

3. The diversity of elements found in large biological molecules

1. The many ways that monomers of each class of biological molecule can be combined into polymers