Question 1

Another name for α-tocopherol is vitamin ________.

Accepted Answer

A) A 
B) B12 
C) C 
D) D 
E) E 
A) A 
B) B12 
C) C 
D) D 
E) E

Question 2

NAD and NADP dependent dehydrogenases catalyze substrates by transferring ________ to C-4 of NAD+ and NADP+.

Accepted Answer

A) one electron 
B) two electrons 
C) one electron and one proton 
D) two electrons and one proton 
E) two electrons and two protons 
A) one electron 
B) two electrons 
C) one electron and one proton 
D) two electrons and one proton 
E) two electrons and two protons

Question 3

Which does not return to its original form after each catalysis?

Accepted Answer

A) Prosthetic groups. 
B) Cosubstrates. 
C) Metalloenzyme. 
D) None of the above.They all return to their original forms. 
A) Prosthetic groups. 
B) Cosubstrates. 
C) Metalloenzyme. 
D) None of the above.They all return to their original forms.

Question 4

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 5

Transaminases are PLP-dependent enzymes that

Accepted Answer

A) remove the alpha-amino group from amino acids. 
B) convert pyruvate to lactate. 
C) degrade heme groups. 
D) donate electrons two at a time. 
A) remove the alpha-amino group from amino acids. 
B) convert pyruvate to lactate. 
C) degrade heme groups. 
D) donate electrons two at a time.

Question 6

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 7

Unlike coenzymes that are prosthetic groups,________ are altered in the course of an enzyme reaction and dissociate from the active site.

Accepted Answer

A) isozymes 
B) cosubstrates 
C) metalloenzymes 
D) holoenzymes 
A) isozymes 
B) cosubstrates 
C) metalloenzymes 
D) holoenzymes

Question 8

Because coenzymes are specific for the chemical groups that they accept and donate,they are referred to as

Accepted Answer

A) cofactors. 
B) reactive centers. 
C) activator ions. 
D) group-transfer reagents. 
E) All of the above. 
A) cofactors. 
B) reactive centers. 
C) activator ions. 
D) group-transfer reagents. 
E) All of the above.

Question 9

The reactive center of coenzyme A is

Accepted Answer

A) ADP. 
B) pantothenate. 
C) alanine. 
D) 2-mercaptoethylamine. 
E) serine. 
A) ADP. 
B) pantothenate. 
C) alanine. 
D) 2-mercaptoethylamine. 
E) serine.

Question 10

We use the term tetrahydrofolate to designate a family of related compounds.What is the main difference between members of this family?

Accepted Answer

A) Degree of protonation. 
B) Number of methyl groups on the heterocylic rings. 
C) Number of phosphate groups. 
D) Length of the polyglutamate tail group. 
A) Degree of protonation. 
B) Number of methyl groups on the heterocylic rings. 
C) Number of phosphate groups. 
D) Length of the polyglutamate tail group.

Question 11

What is the prosthetic group of the retinal vision protein rhodopsin?

Accepted Answer

A) Retinol. 
B) Retinal. 
C) Retinoic acid. 
D) β-carotene. 
A) Retinol. 
B) Retinal. 
C) Retinoic acid. 
D) β-carotene.

Question 12

In which type of reactions does Q participate?

Accepted Answer

A) One electron transfers only. 
B) One or two electron transfers. 
C) Hydride ion transfers. 
D) Acetyl group transfers. 
A) One electron transfers only. 
B) One or two electron transfers. 
C) Hydride ion transfers. 
D) Acetyl group transfers.

Question 13

Which type of atom is involved in the reactive center of lipoamide?

Accepted Answer

A) Sulfur. 
B) Nitrogen. 
C) Phosphorous. 
D) Oxygen. 
A) Sulfur. 
B) Nitrogen. 
C) Phosphorous. 
D) Oxygen.

Question 14

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.

Question 15

Ubiquinone and plastoquinone transport electrons in membranes.

Accepted Answer

A) True 
 B)False

Question 16

Which structure is not a part of folate?

Accepted Answer

A) Porphyrin ring. 
B) P-aminobenzoic acid. 
C) Pterin. 
D) Glutamate residues. 
A) Porphyrin ring. 
B) P-aminobenzoic acid. 
C) Pterin. 
D) Glutamate residues.

Question 17

Two-electron transfer reactions can be linked to one-electron transfer reactions by

Accepted Answer

A) formation of semiquinones. 
B) a [Fe-S] cluster. 
C) NADH and NADPH. 
D) B and C. 
E) A and C. 
A) formation of semiquinones. 
B) a [Fe-S] cluster. 
C) NADH and NADPH. 
D) B and C. 
E) A and C.

Question 18

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 19

What kind of reaction is most important for the reactive center of lipoamide?

Accepted Answer

A) Oxidation of a carbonyl group. 
B) Reduction of a disulfide bond. 
C) Formation of a Schiff base. 
D) A cis-trans configurational change about a disulfide bond. 
A) Oxidation of a carbonyl group. 
B) Reduction of a disulfide bond. 
C) Formation of a Schiff base. 
D) A cis-trans configurational change about a disulfide bond.

Question 20

Match each of the following vitamins with an associate nutritional deficiency disease.
-Thiamine (B1)

Accepted Answer

A) Pernicious anemia 
B) anemia 
C) Dermititis in humans 
D) scurvy 
E) beriberi 
A) Pernicious anemia 
B) anemia 
C) Dermititis in humans 
D) scurvy 
E) beriberi

Exam 7: Coenzymes and Vitamins

Another name for α-tocopherol is vitamin ________.

NAD and NADP dependent dehydrogenases catalyze substrates by transferring ________ to C-4 of NAD+ and NADP+.

Which does not return to its original form after each catalysis?

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

Transaminases are PLP-dependent enzymes that

Pyridoxal phosphate is involved in which type of reaction?

Unlike coenzymes that are prosthetic groups,________ are altered in the course of an enzyme reaction and dissociate from the active site.

Because coenzymes are specific for the chemical groups that they accept and donate,they are referred to as

The reactive center of coenzyme A is

We use the term tetrahydrofolate to designate a family of related compounds.What is the main difference between members of this family?

What is the prosthetic group of the retinal vision protein rhodopsin?

In which type of reactions does Q participate?

Which type of atom is involved in the reactive center of lipoamide?

Acyl-group-transfer reactions often involve which coenzyme?

Ubiquinone and plastoquinone transport electrons in membranes.

Which structure is not a part of folate?

Two-electron transfer reactions can be linked to one-electron transfer reactions by

Vitamin K is important in the ________.

What kind of reaction is most important for the reactive center of lipoamide?

Match each of the following vitamins with an associate nutritional deficiency disease. -Thiamine (B1)

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 Atp Synthesis

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

DNA Replication, repair, and Recombination

Transcription and RNA Processing

Protein Synthesis

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