AP Bio Ch. 3 Test

Which of the following molecules lacks amino acids?

cholesterol

How many electron pairs does carbon share in order to complete its valence shell?

4

If 1 strand of a DNA molecule has the sequence of bases 5'-ATTGCA-3', the other complementary strand would have the sequence

5'-TGCAAT-3'

The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions?

C18H32O16

Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. How do these molecules differ from each other?

Testosterone and estradiol have different functional groups attached to the same carbon skeleton

Which of the following statements about the 5' ends of RNA polymers is correct?

The 5' ends have phosphate groups attached to the number 5 carbons of ribose

Which is an example of a dehydration reaction?

The reaction of 2 monosaccharides forming a disaccharide with the release of water

Which of the following is an example of a hydrolysis reaction?

The reaction of a fat, forming glycerol and fatty acids with the consumption of water

A nucleotide is composed of

a nitrogenous base, a phosphate group, and a pentose sugar

Ibuprofen is a drug commonly used to relieve inflammation and pain. It is a mixture of two enantiomers, which are molecules that a. have mirror images of one another b. have identical chemical formulas but differ in the branching of their carbon skeletons c. exist in either linear chain or ring forms d. differ in the arrangement of atoms around their double bonds

a. are mirror images of one another

Lactose, a sugar in milk, is composed of 1 glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified? a. as a disaccharide b. as a monosaccharide c. as a polysaccharide d. as a hexose e. as a pentose

a. as a disaccharide

Which bonds are created during the formation of the primary structure of a protein? a. peptide bonds b. disulfide bonds c. hydrogen bonds d. phosphodiester bonds

a. peptide bonds

A carbon atom is most likely to form what kind of bond(s) with other atoms? a. covalent bonds b. covalent & hydrogen bonds c. ionic bonds d. hydrogen bonds

a. covalent bonds

Which of the following statements is true regarding cellulose? a. it is a primary structural component of plant cell walls b. it is a polymer composed of enantiomers of glucose c. it is digestible by bacteria in the human gut d. it is a polymer of glucose joined by a glycosidic linkage e. it is a storage polysaccharide for energy in plant cells

a. it is a primary structural component of plant cell walls

Which of the following common chemical groups is hydrophobic? a. methyl b. carboxyl c. hydroxyl d. amino

a. methyl

Which of the following will be most soluble in water? a. organic hydrocarbons with hydroxyl groups attached b. organic hydrocarbons c. organic hydrocarbons with sulfhydryl groups attached d. organic hydrocarbons with methyl groups attached

a. organic hydrocarbons with hydroxyl groups attached

The structural level of a protein least affected by a disruption in hydrogen bonding is the: a. primary level b. secondary level c. tertiary level d. quaternary level

a. primary level

Collagen is a protein made of 3 identical polypeptides composed primarily of an alpha helix structure. The alpha helix is an example of a a. secondary structure stabilized by hydrogen bonds b. tertiary structure stabilized by covalent bonds c. secondary structure stabilized by covalent bonds d. tertiary structure stabilized by hydrogen bonds e. secondary structure stabilized by ionic bonds

a. secondary structure stabilized by hydrogen bonds

Choose the term that correctly describes the relationship between these two sugar molecules: a. structural isomers b. cis-trans isomers c. isotopes d. enantiomers

a. structural isomers

Which functional group is not present in this molecule? (has HO-C--O, -OH, -NH2) a. sulfhydryl b. amino c. carboxyl d. hydroxyl

a. sulfhydryl

DNase is an enzyme that catalyzes the hydrolysis of the covalent bonds that join nucleotides together. What would first happen to DNA molecules treated with DNase? a. the bonds between deoxyribose phosphate groups would be broken b. the deoxyribose and bases would be broken c. the 2 strands of the double helix would separate d. oxygen atoms would be removed from the deoxyribose sugars

a. the bonds between deoxyribose phosphate groups would be broken

Why are hydrocarbons insoluble in water? a. the majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages b. the majority of their bonds are polar covalent carbon-to-hydrogen linkages c. they exhibit considerable molecular complexity and diversity d. they are hydrophilic

a. the majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages

Ethane gas is a molecule that consists of two tetrahedral groups of single-bonded atoms. Which of the following would change the configuration of these atoms from a tetrahedral configuration to a planar configuration?

a. the presence of double covalent bonds between the 2 carbon atoms and single covalent bonds between carbon and hydrogen atoms

Normal hemoglobin is a tetramer, consisting of 2 molecules of B-globin and 2 molecules of A-globin. In sickle cell disease, because of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemble into large fibers. Based on this information alone, we can conclude that sickle cell hemoglobin exhibits

altered primary structure & altered quaternary structure; the secondary & tertiary structures may or may not be altered

How many electron pairs are shared between 2 carbon atoms when they re joined by a double bond? a. 1 b. 2 c. 3 d. 4

b. 2

If a DNA sample were composed of 20% guanine, what would be the percentage of cytosine? a. 40 b. 20 c. 30 d. 60

b. 20

Which of the following statements regarding lipids is true? a. a gram of lipid stores less energy than a gram of carbohydrate b. they are insoluble in water c. they generally contain nitrogen d. they are made from glycerol and amino acids

b. They are insoluble in water.

Which chemical group is most likely to be responsible for an organic molecule behaving as a base? a. phosphate b. amino c. carbonyl d. hydroxyl

b. amino

Which of the following large biological molecules will self-assemble into a bilayer when mixed with water? a. steroids b. phospholipids c. cellulose d. triacylglycerols

b. phospholipids

Bonds formed between the side chains (R groups) in a polypeptide are most important in stabilizing which of the following? a. quaternary structure b. tertiary structure c. primary structure d. secondary structure

b. tertiary structure

Which of the following statements concerning saturated fats is true? a. they contain fewer hydrogen atoms than unsaturated fats having the same number of carbon atoms b. they are generally solid at room temperature c. they are more common in plants than in animals d. they have multiple double bonds in the carbon chains of their fatty acids

b. they are generally solid at room temperature

Which of the following statements concerning unsaturated fats is true? a. they generally solidify at room temperature b. they have double bonds in their fatty acid chains c. they contain more hydrogen than do saturated fats having the same number of carbon atoms d. they are more common in animals than in plants

b. they have double bonds in their fatty acid chains

If a DNA sample were composed of 15% adenine, what would be the percentage of guanine? a. 30 b. 45 c. 35 d. 15

c. 35%

How many peptide bonds are present in a polypeptide that contains 45 amino acids? a. 45 b. 46 c. 44 d. 90

c. 44

The molecular formula for glucose is C6H12O6. What would be the molecular formula for a polymer made by linking 10 glucose molecules together by dehydration reactions? a. C60H100O50 b. C60H120O60 c. C60H102O51 d. C60H111O51

c. C60H102O51

Which of the following is a correct monomer/ polymer pairing? a. glycerol/ triglyceride b. monosaccharide/ polypeptide c. amino acid/ polypeptide d. amino acid/ polysaccharide

c. amino acid/ polypeptide

Which of the following categories including all others in the list? a. starch b. disaccharide c. carbohydrate d. polysaccharide

c. carbohydrate

The term insoluble fiber on food packaging generally refers to which of the following carbohydrates? a. glycogen b. sucrose c. cellulose d. starch

c. cellulose

Which of the following polymers lacks nitrogen? a. RNA b. protein c. glycogen d. chitin

c. glycogen

If cells are grown in a medium containing radioactive 32P, which of these molecules will be radioactively labeled? a. starch b. triacylglycerols c. nucleic acids d. fatty acids

c. nucleic acids

In a normal cellular protein, where would you expect to find a hydrophilic amino acid such as asparagine? a. on the exterior surface of the protein, interacting with water, or in a transmembrane portion, interacting with the lipid fatty acid chains b. in the transmembrane portion, interacting with lipid fatty acid chains c. on the exterior surface of the protein, interacting with water d. in the interior of the folded protein, away from water

c. on the exterior surface of the protein, interacting with water

If cells are grown in a medium containing radioactive 35S, which of these molecules will be labeled? a. nucleic acids b. starch c. proteins d. triacylglycerols

c. proteins

Amylase is an enzyme that hydrolyzes glycosidic linkages between glucose monomers only if the monomers are the A form. Which of the following macromolecules can be broken down by amylase? a. cellulose b. starch and chitin c. starch d. chitin

c. starch

Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes? a. the pyrimidines would be separated from the deoxyribose sugars b. the two strands of the double helix would separate c. the phosphodiester linkages of the polynucleotide backbone would be broken d. all bases would be separated from the deoxyribose sugars

c. the phosphodiester linkages of the polynucleotide backbone would be broken

Why are the vertebrate sex hormones estrogen and testosterone considered to be lipids? a. they are essential components of cell membranes b. they are made of fatty acids c. their carbon skeletons are composed of primarily C-C and C-H bonds d. they are hydrophilic compounds

c. their carbon skeletons are composed of primarily C-C and C-H bonds

Dehydration reactions are responsible for the formation of which of the following? a. amino acids b. fatty acids c. triacylglycerols d. monosaccharides

c. triacylglycerols

Which 2 functional groups are always found in amino acids?

carboxyl and amino

Which of the following hydrocarbons has a double bond in its carbon skeleton? a. C2H2 b. C2H6 c. C3H8 d. C2H4

d. C2H4

If 14C-labeled uracil is added to the growth medium of cells, what macromolecules will be labeled? a. polysaccharides b. proteins c. both DNA and RNA d. RNA e. DNA

d. RNA

Which of the following molecules is not a polymer synthesized from several simple monomers? a. DNA b. an enzyme c. cellulose d. a steroid

d. a steroid

Which of the following classes of biological molecules consist of both small molecule monomers and macromolecule polymers? a. nucleic acids b. lipids c. proteins d. carbohydrates

d. carbohydrates

Which of the following polymers are assembled with monomers containing nitrogen? a. cellulose b. starch c. glucogen d. chitin

d. chitin

Which of the following functional groups may be used to form polymers via dehydration reactions? a. only carbonyl groups b. only carboxyl groups c. only hydroxyl groups d. either hydroxyl or carboxyl groups e. either carbonyl or carboxyl groups

d. either hydroxyl or carboxyl groups

A molecule with the formula C18H36O2 is most likely a a. hydrocarbon b. polysaccharide c. carbohydrate d. fatty acid

d. fatty acid

A molecule with the chemical formula C6H12O6 is probably a a. hydrocarbon b. glycerol c. lipid d. monosaccharide

d. monosaccharide

Which of the following is the smallest carbohydrate? a. starch b. chitin c. glycogen d. sucrose e. cellulose

d. sucrose

Lactase is an enzyme composed of a single polypeptide that hydrolyzes the disaccharide lactose to produce monosaccharides. The optimal pH for lactase activity is 6. Transfer of lactase to pH 5 results in a substantial decrease in enzyme activity, likely due to the disruption of a. the primary & secondary structures of the enzyme b. the secondary, tertiary, and quaternary structures of the enzyme c. only the primary structure of the enzyme d. the secondary & tertiary structures of the enzyme

d. the secondary & tertiary structures of the enzyme

Which of the following chemical equations describes a hydrolysis reaction?

disaccharide + H2O= monosaccharide + monosaccharide

Which of the following functional groups confers the properties of an acid on amino acids? a. amino b. hydroxyl c. carbonyl d. phosphate e. carboxyl

e. carboxyl

Which of the following statements regarding saturated fatty acids is true? a. they contain 1 or 2 double bonds in their hydrocarbon tails b. they are the primary lipids produced by plants c. they are usually liquid at room temperature d. they are the predominant fatty acid in corn oil e. they are the principal molecules in lard and butter

e. they are the principal molecules in lard and butter

Which of the following are purines?

guanine and adenine

What maintains the secondary structure of a protein?

hydrogen bonds between the amino group of one peptide bond and the carboxyl group of another peptide bond

If cells are grown in a medium containing radioactive 15N, which of these molecules will be labeled?

proteins and nucleic acids

How will brief heating (to 95°C) affect macromolecular structures in aqueous solution?

proteins will unfold (denature)

Polysaccharides, triacylglycerols, and proteins are similar in that they are

synthesized from subunits by dehydration reactions

Which of the following structures is formed by the atoms involved when a carbon atom is bound by a single covalent bond to 4 other atoms?

tetrahedron