Chapter 5 (26-51)

Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded polypeptides? A) Alzheimer's and Parkinson's B) diabetes mellitus C) Parkinson's D) Alzheimer's

A) Alzheimer's and Parkinson's

The molecular formula for glucose is C6H12O6. What would be the molecular formula for a polymer made by linking ten glucose molecules together by dehydration reactions? A) C60H102O51 B) C60H100O50 C) C60H111O51 D) C60H120O60

A) C60H102O51

If 14C-labeled uracil is added to the growth medium of cells, what macromolecules will be labeled? A) RNA B) polypeptides C) both DNA and RNA D) DNA

A) RNA

Which of the following categories includes all others in the list? A) carbohydrate B) disaccharide C) polysaccharide D) starch

A) carbohydrate

Cooking oil and gasoline (a hydrocarbon) are not amphipathic molecules because they ________. A) do not have a polar or charged region B) have hydrophobic and hydrophilic regions C) are highly reduced molecules D) do not have a nonpolar region

A) do not have a polar or charged region

What is the major structural difference between starch and glycogen? A) the amount of branching that occurs in the molecule B) whether glucose is in the α or β form C) the types of monosaccharide subunits in the molecules D) the type of glycosidic linkages in the molecule

A) the amount of branching that occurs in the molecule

In an RNA sample, ________. A) the number of purine may or may not equal the number of and pyrimidine B) the number of purine always equals the number of pyrimidine C) the number of thiamine may or may not equal the number of adenine D) the number of thiamine always equals the number of uracil

A) the number of purine may or may not equal the number of and pyrimidine

Maltose is a disaccharide that can easily be digested into glucose molecules. The glycosidic linkage between glucose molecules in maltose is ________. A) α 1—4 B) β 1—2 C) β 1—4 D) α 1—2

A) α 1—4

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? A) C18H36O18 B) C18H32O16 C) C6H10O5 D) C18H30O15

B) C18H32O16

You have just sequenced a new protein found in mice and observe that sulfur-containing cysteine residues occur at regular intervals. What is the significance of this finding? A) Cysteine causes bends, or angles, to occur in the tertiary structure of proteins. B) Cysteine residues are involved in disulfide bridges that help form tertiary structure. C) It will be important to include cysteine in the diet of the mice. D) Cysteine residues are required for the formation of α helices and β pleated sheets.

B) Cysteine residues are involved in disulfide bridges that help form tertiary structure.

Which polysaccharide is an important component in the structure of many animals and fungi? A) cellulose B) chitin C) amylose D) amylopectin

B) chitin

You disrupt all hydrogen bonds in a protein. What level of structure will be preserved? A) quaternary structure B) primary structure C) secondary structure D) tertiary structure

B) primary structure

The difference between an aldose sugar and a ketose sugar is ________. A) the number of carbon atoms B) the position of the carbonyl group C) the position of the hydroxyl groups D) the ring form and the linear chain

B) the position of the carbonyl group

How many molecules of water are released during the polymerization of a 20 monomer-long cellulose molecule? A) 20 B) 10 C) 19 D) 40

C) 19

If one strand of a DNA molecule has the sequence of bases 5′-ATTGCA-3′, the mRNA synthesized following the template will be ________. A) 5′-UGCAAU-3′ B) 5′-TAACGT-3′ C) 3′-UAACGU-5′ D) 5′-TGCAAT-3′

C) 3′-UAACGU-5′

Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA? A) 5′-AGCT-3′ with 5′-TCGA-3′ B) 5′-GCGC-3′ with 5′-TATA-3′ C) 5′-ATGC-3′ with 5′-GCAT-3′ D) All of these pairs are correct.

C) 5′-ATGC-3′ with 5′-GCAT-3′

The central rule of molecular biology states that ________. A) RNA is transcribed into protein B) DNA is translated into protein C) DNA is transcribed into RNA, which is translated into protein D) DNA is translated into RNA, which is transcribed into protein

C) DNA is transcribed into RNA, which is translated into protein

For lipids to be fluid at room temperature, they should have ________. A) single bonds only B) a longer carbon chain C) a higher number of cis double bonds D) a higher number of glycerol molecules

C) a higher number of cis double bonds

Which of the following descriptions best fits the class of molecules known as nucleotides? A) a nitrogenous base and a sugar B) a nitrogenous base and a phosphate group C) a nitrogenous base, a phosphate group, and a sugar D) a sugar and a purine or pyrimidine

C) a nitrogenous base, a phosphate group, and a sugar

Starch is composed of ________. A) unbranched amylopectin and unbranched amylose B) branched amylopectin and branched amylose C) branched amylopectin and unbranched amylose D) unbranched amylopectin and branched amylose

C) branched amylopectin and unbranched amylose

Which parts of the amino acids X and Y are involved in the formation of a peptide bond? X—Y A) amino group of X and carboxyl group of Y B) carboxyl group of X and side chain of Y C) carboxyl group of X and amino group of Y D) side chains of both X and Y

C) carboxyl group of X and amino group of Y

The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are in the form. Which of the following could amylase break down? A) starch, chitin, and cellulose B) glycogen and cellulose C) glycogen, starch, and amylopectin D) cellulose and chitin

C) glycogen, starch, and amylopectin

In carbohydrates, the ratio of hydrogen (H) to oxygen (O) is ________. A) 3:1 B) 1:1 C) 4:1 D) 2:1

D) 2:1

The table represents the results of an experiment where the effects of pH buffers on an enzyme found in saliva (amylase) were studied. A spectrophotometer set at 500 nm was used to measure absorbance at the various pH levels every 20 seconds for 2 minutes. The higher absorbance values would indicate greater enzyme activity. All experiments were conducted at the same temperature. Which statement correctly identifies the result that the optimum pH for amylase function is 7? A) At pH 9, the enzyme is denatured and will lose its function, but not its structure. B) The pH with the lowest absorbance values would indicate the optimum pH for amylase since this pH does not affect the structure or function of the protein. C) At pH 4, the structure of the enzyme will be altered, and the enzyme would not be able to catalyze the reaction. D) The pH with the highest absorbance values would indicate the optimum pH for amylase since this pH does not affect the structure or function of the protein.

D) The pH with the highest absorbance values would indicate the optimum pH for amylase since this pH does not affect the structure or function of the protein.

Which of the following is true of unsaturated fats? A) They generally solidify at room temperature. B) They are more common in animals than in plants. C) They contain more hydrogen than do saturated fats having the same number of carbon atoms. D) They have double bonds in their fatty acid chains.

D) They have double bonds in their fatty acid chains.

What component of amino acid structure varies among different amino acids? A) the presence of a central C atom B) the glycerol molecule that forms the backbone of the amino acid C) the long carbon-hydrogen tails of the molecule D) the components of the R group

D) the components of the R group