Question 1

Lipid vitamins such as A, D, E, and K are stored by animal cells, so excessive daily intake may be toxic.

Accepted Answer

A) True 
 B)False

Question 2

Lack of thiamine vitamin B1) leads to the disease beriberi.

Accepted Answer

A) True 
 B)False

Question 3

Which functional group is shown below?

Accepted Answer

A)  Schiff base 
B)  secondary amine 
C)  amide 
D)  peptide bond 
A)  Schiff base 
B)  secondary amine 
C)  amide 
D)  peptide bond

Question 4

Vitamin K is important in the .

Accepted Answer

A)  synthesis of collagen 
B)  absorption of Ca2+ 
C)  coagulation of blood clotting) 
D)  scavenging of oxygen and free radicals 
A)  synthesis of collagen 
B)  absorption of Ca2+ 
C)  coagulation of blood clotting) 
D)  scavenging of oxygen and free radicals

Question 5

TPP is a/an of yeast pyruvate decarboxylase.

Accepted Answer

A)  cosubstrate 
B)  intrinsic factor 
C)  metalloenzyme 
D)  prosthetic group 
A)  cosubstrate 
B)  intrinsic factor 
C)  metalloenzyme 
D)  prosthetic group

Question 6

Pernicious anemia is caused by a deficiency in biotin.

Accepted Answer

A) True 
 B)False

Question 7

Why has dihydrofolate reductase been identified as a potential target for chemotherapy in the treatment of cancer?

Accepted Answer

A)  It is a hormone that is a primary control agent of the rate of mitosis. 
B)  It is a DNA binding protein that activates a cancer oncogene. 
C)  It is essential in DNA synthesis. Cell division will not occur without it. 
D)  It selectively binds to a receptor on the surface of cancer cells and inactivates them. 
A)  It is a hormone that is a primary control agent of the rate of mitosis. 
B)  It is a DNA binding protein that activates a cancer oncogene. 
C)  It is essential in DNA synthesis. Cell division will not occur without it. 
D)  It selectively binds to a receptor on the surface of cancer cells and inactivates them.

Question 8

Vitamin E is formed non-enzymatically in sun-exposed skin.

Accepted Answer

A) True 
 B)False

Question 9

Lysine can join the prosthetic group biotin to an enzyme via an amide link at the ε-amino group.

Accepted Answer

A) True 
 B)False

Question 10

Pyridoxal phosphate is involved in which type of reaction?

Accepted Answer

A)  oxidation of pyruvate 
B)  production of new amino acids by transamination 
C)  phosphate-transfer to produce ATP from ADP 
D)  the regeneration of methionine from homocysteine 
A)  oxidation of pyruvate 
B)  production of new amino acids by transamination 
C)  phosphate-transfer to produce ATP from ADP 
D)  the regeneration of methionine from homocysteine

Question 11

The products) of lactate dehydrogenase under anaerobic conditions is are)

Accepted Answer

A)  pyruvic acid. 
B)  NAD+. 
C)  NADH. 
D)  A and B 
E)  A and C 
A)  pyruvic acid. 
B)  NAD+. 
C)  NADH. 
D)  A and B 
E)  A and C

Question 12

S-adenosylmethionine SAM) is formed from the amino acid methionine so that

Accepted Answer

A)  methyl groups can be formed. 
B)  it can react with nucleophilic acceptors. 
C)  it can donate methyl groups in many biosynthetic reactions. 
D)  All of the above 
E)  B and C 
A)  methyl groups can be formed. 
B)  it can react with nucleophilic acceptors. 
C)  it can donate methyl groups in many biosynthetic reactions. 
D)  All of the above 
E)  B and C

Question 13

Active holoenzymes are formed from in the presence of .

Accepted Answer

A)  cofactors; proteins 
B)  proteins; cofactors 
C)  apoenzymes; cofactors 
D)  apoenzymes; proteins 
E)  apoenzymes; inactive holoenzymes 
A)  cofactors; proteins 
B)  proteins; cofactors 
C)  apoenzymes; cofactors 
D)  apoenzymes; proteins 
E)  apoenzymes; inactive holoenzymes

Question 14

Another name for vitamin K is phylloquinone.

Accepted Answer

A) True 
 B)False

Question 15

Unlike NADH and NADPH, FAD and FADH

Accepted Answer

A)  donate one electron at a time. 
B)  donate one or two electrons at a time. 
C)  do not become positively charged. 
D)  A and C 
E)  B and C 
A)  donate one electron at a time. 
B)  donate one or two electrons at a time. 
C)  do not become positively charged. 
D)  A and C 
E)  B and C

Question 16

Which atom is the reactive center on biotin?

Accepted Answer

A)  Arrow 1 
B)  Arrow 2 
C)  Arrow 3 
D)  Arrow 4 
A)  Arrow 1 
B)  Arrow 2 
C)  Arrow 3 
D)  Arrow 4

Question 17

A nucleotide-sugar coenzyme involved in carbohydrate metabolism UDP-glucose) is formed when UTP reacts with a glucose molecule. More UTP is made available for additional reactions by the transfer of a phosphate group from

Accepted Answer

A)  another carbohydrate. 
B)  ATP. 
C)  ADP. 
D)  UTP. 
E)  UDP. 
A)  another carbohydrate. 
B)  ATP. 
C)  ADP. 
D)  UTP. 
E)  UDP.

Question 18

There is little risk in taking megadoses of vitamin A since excess will tend to simply be excreted in the urine.

Accepted Answer

A) True 
 B)False

Question 19

The reactive center of CoA is the -NH3+ group.

Accepted Answer

A) True 
 B)False

Question 20

Acyl-group-transfer reactions often involve which coenzyme?

Accepted Answer

A)  Coenzyme A 
B)  NAD+ 
C)  cytochrome c 
D)  All of the above 
A)  Coenzyme A 
B)  NAD+ 
C)  cytochrome c 
D)  All of the above

Exam 7: Coenzymes and Vitamins

Lipid vitamins such as A, D, E, and K are stored by animal cells, so excessive daily intake may be toxic.

Lack of thiamine vitamin B1) leads to the disease beriberi.

Which functional group is shown below?

Vitamin K is important in the .

TPP is a/an of yeast pyruvate decarboxylase.

Pernicious anemia is caused by a deficiency in biotin.

Why has dihydrofolate reductase been identified as a potential target for chemotherapy in the treatment of cancer?

Vitamin E is formed non-enzymatically in sun-exposed skin.

Lysine can join the prosthetic group biotin to an enzyme via an amide link at the ε-amino group.

Pyridoxal phosphate is involved in which type of reaction?

The products) of lactate dehydrogenase under anaerobic conditions is are)

S-adenosylmethionine SAM) is formed from the amino acid methionine so that

Active holoenzymes are formed from in the presence of .

Another name for vitamin K is phylloquinone.

Unlike NADH and NADPH, FAD and FADH

Which atom is the reactive center on biotin?

A nucleotide-sugar coenzyme involved in carbohydrate metabolism UDP-glucose) is formed when UTP reacts with a glucose molecule. More UTP is made available for additional reactions by the transfer of a phosphate group from

There is little risk in taking megadoses of vitamin A since excess will tend to simply be excreted in the urine.

The reactive center of CoA is the -NH3+ group.

Acyl-group-transfer reactions often involve which coenzyme?

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

Dna Replication, Repair, and Recombination

Transcription and Rna Processing

Protein Synthesis

Recombinant Dna Technology

Filters

Lack of thiamine vitamin B₁) leads to the disease beriberi.

The reactive center of CoA is the -NH₃⁺group.