Question 1

Identify all group(s)that tetrahydrofolate transfers.

Accepted Answer

A) methylene 
B) methyl 
C) ethyl 
D) formyl 
E) propyl 
A) methylene 
B) methyl 
C) ethyl 
D) formyl 
E) propyl

Question 2

At what position on the following coenzyme (FAD/FMN)will oxidation-reduction reactions take place?

Accepted Answer

A) 6 
B) 2 
C) 3 
D) 4 
E) 5 
A) 6 
B) 2 
C) 3 
D) 4 
E) 5

Question 3

Give the purpose of thymidylate synthase.

Accepted Answer

A) converts cytosine to guanine 
B) converts guanine to cytosine 
C) converts thymine to uracil 
D) converts uracil to thymine 
E) converts adenine to guanine 
A) converts cytosine to guanine 
B) converts guanine to cytosine 
C) converts thymine to uracil 
D) converts uracil to thymine 
E) converts adenine to guanine

Question 4

Propose a mechanism for the vitamin KH2-catalyzed carboxylation of glutamate shown below:

Accepted Answer

Question 5

Which of the following statements best describes what an "electron sink" is?

Accepted Answer

A) a free radical initiator for enzyme catalysis 
B) a site for electron localization 
C) a site for electron delocalization 
D) a site that donates electrons for enzyme catalysis 
E) a site that accepts electrons for enzyme catalysis 
A) a free radical initiator for enzyme catalysis 
B) a site for electron localization 
C) a site for electron delocalization 
D) a site that donates electrons for enzyme catalysis 
E) a site that accepts electrons for enzyme catalysis

Question 6

Which coenzyme is needed in the conversion of b-aspartate-semialdehyde to homoserine, a reduction reaction?

Accepted Answer

A) NADPH 
B) biotin 
C) PLP 
D) lipoate 
E) THF 
A) NADPH 
B) biotin 
C) PLP 
D) lipoate 
E) THF

Question 7

At what position of the pyridinium ring in the coenzyme below will oxidation-reduction reactions take place?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) 5 
A) 1 
B) 2 
C) 3 
D) 4 
E) 5

Question 8

Which of the following vitamins catalyzes one-carbon transfer reactions and requires THF as a coenzyme?

Accepted Answer

A) biotin 
B) thiamine 
C) folic acid 
D) ascorbic acid 
E) panthothenate 
A) biotin 
B) thiamine 
C) folic acid 
D) ascorbic acid 
E) panthothenate

Question 9

Give the purpose of vitamin KH2 as a coenzyme.

Accepted Answer

A) catalyzes the carboxylation of the alpha-carbon of the glutamate side chain in proteins 
B) catalyzes the carboxylation of the beta-carbon of the glutamate side chain in proteins 
C) catalyzes the carboxylation of the beta-carbon of the aspartate side chain in proteins 
D) catalyzes the carboxylation of the gamma-carbon of the glutamate side chain in proteins 
E) catalyzes the carboxylation of the alpha-carbon of the aspartate side chain in proteins 
A) catalyzes the carboxylation of the alpha-carbon of the glutamate side chain in proteins 
B) catalyzes the carboxylation of the beta-carbon of the glutamate side chain in proteins 
C) catalyzes the carboxylation of the beta-carbon of the aspartate side chain in proteins 
D) catalyzes the carboxylation of the gamma-carbon of the glutamate side chain in proteins 
E) catalyzes the carboxylation of the alpha-carbon of the aspartate side chain in proteins

Question 10

Which of the following statements is/are true about metabolism?

Accepted Answer

A) reactions that living organisms carry out to obtain energy and to synthesize required compounds 
B) reactions that organic chemists carry out to obtain energy and to synthesize required compounds 
C) reactions that consist of catabolic and anabolic reactions 
D) A and C 
E) B and C 
A) reactions that living organisms carry out to obtain energy and to synthesize required compounds 
B) reactions that organic chemists carry out to obtain energy and to synthesize required compounds 
C) reactions that consist of catabolic and anabolic reactions 
D) A and C 
E) B and C

Question 11

Which of the following are required species for biotin-dependent enzymes?

Accepted Answer

A) ATP 
B) Mg+2 
C) HCO3- 
D) A and B 
E) A, B and C 
A) ATP 
B) Mg+2 
C) HCO3- 
D) A and B 
E) A, B and C

Question 12

How does NAD+ serve as a catalyst in oxidation reactions?

Accepted Answer

A) It accepts a hydride ion at the 4-position of its pyridinium ring. 
B) It accepts a hydride ion at the amide carbonyl group at the 3-position. 
C) It accepts a proton at the 4-position of its pyridinium ring. 
D) It accepts a proton at the amide carbonyl group at the 3-position. 
E) none of the above 
A) It accepts a hydride ion at the 4-position of its pyridinium ring. 
B) It accepts a hydride ion at the amide carbonyl group at the 3-position. 
C) It accepts a proton at the 4-position of its pyridinium ring. 
D) It accepts a proton at the amide carbonyl group at the 3-position. 
E) none of the above

Question 13

The thymine molecule used for the biosynthesis of DNA is synthesized from uracil as shown below.   The structure of dTMP is a methylated dUMP. What is the structure of dTMP?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) V 
A) I 
B) II 
C) III 
D) IV 
E) V

Question 14

Propose a mechanism for the following reaction.

Accepted Answer

The answer of Propose a mechanism for the following reaction....

Question 15

The thiazolium ring of ________ acts as electron sink when it participates in metabolic reactions.

Accepted Answer

A) TTP 
B) CoASH 
C) PLP 
D) THF 
E) FAD 
A) TTP 
B) CoASH 
C) PLP 
D) THF 
E) FAD

Question 16

Give the purpose of biotin.

Accepted Answer

Biotin is the coenzy

Question 17

Give the product for the following reaction.

Accepted Answer

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

Question 18

Identify the compound below.

Accepted Answer

A) coenzyme A 
B) thiamine pyrophosphate 
C) pyruvate 
D) NADPH 
E) tetrahydrofolate 
A) coenzyme A 
B) thiamine pyrophosphate 
C) pyruvate 
D) NADPH 
E) tetrahydrofolate

Question 19

Which of the following vitamins catalyzes acyl transfer reactions and requires CoASH as a coenzyme?

Accepted Answer

A) niacin 
B) thiamine 
C) vitamin B12 
D) lipoate 
E) panthothenate 
A) niacin 
B) thiamine 
C) vitamin B12 
D) lipoate 
E) panthothenate

Question 20

Which of the following statements best describes what cofactors are?

Accepted Answer

A) They are metal ions that assist enzymes in carrying out their catalytic reactions. 
B) They are organic molecules that assist enzymes in carrying out their catalytic reactions. 
C) They are organic molecules called coenzymes. 
D) They are organic molecules derived from compounds commonly known as vitamins. 
E) all of the above 
A) They are metal ions that assist enzymes in carrying out their catalytic reactions. 
B) They are organic molecules that assist enzymes in carrying out their catalytic reactions. 
C) They are organic molecules called coenzymes. 
D) They are organic molecules derived from compounds commonly known as vitamins. 
E) all of the above

Exam 24: The Organic Mechanisms of the Coenzymes

Identify all group(s)that tetrahydrofolate transfers.

At what position on the following coenzyme (FAD/FMN)will oxidation-reduction reactions take place?

Give the purpose of thymidylate synthase.

Propose a mechanism for the vitamin KH2-catalyzed carboxylation of glutamate shown below:

Which of the following statements best describes what an "electron sink" is?

Which coenzyme is needed in the conversion of b-aspartate-semialdehyde to homoserine, a reduction reaction?

At what position of the pyridinium ring in the coenzyme below will oxidation-reduction reactions take place?

Which of the following vitamins catalyzes one-carbon transfer reactions and requires THF as a coenzyme?

Give the purpose of vitamin KH2 as a coenzyme.

Which of the following statements is/are true about metabolism?

Which of the following are required species for biotin-dependent enzymes?

How does NAD+ serve as a catalyst in oxidation reactions?

The thymine molecule used for the biosynthesis of DNA is synthesized from uracil as shown below. The structure of dTMP is a methylated dUMP. What is the structure of dTMP?

Propose a mechanism for the following reaction.

The thiazolium ring of ________ acts as electron sink when it participates in metabolic reactions.

Give the purpose of biotin.

Give the product for the following reaction.

Identify the compound below.

Which of the following vitamins catalyzes acyl transfer reactions and requires CoASH as a coenzyme?

Which of the following statements best describes what cofactors are?

Remembering General Chemistry: Electronic Structure and Bonding

Acids and Bases: Central to Understanding Organic Chemistry

An Introduction to Organic Compounds

Isomers: the Arrangement of Atoms in Space

Alkenes Thermodynamics and Kinetics

Reactions of Alkenes

Reactions of Alkynes Introduction to Multistep Synthesis

Electron Delocalization, Resonance, and Aromaticity More About Molecular Orbital Theory

Substitution Reactions of Alkyl Halides

Elimination Reactions of Alkyl Halides Competition Between Substitution and Elimination

Reactions of Alcohols, Ethers, Epoxides, and Sulfur-Containing Compounds

Organometallic Compounds

Reactions of Alkanes, Radicals

Mass Spectrometry, Infrared Spectroscopy, and Uvvis Spectroscopy

Nmr Spectroscopy

Reactions of Carboxylic Acids and Carboxylic Acid Derivatives

Reactions of Aldehydes and Ketones

Reactions at the Alpha Carbon of Carbonyl Compounds

Reactions of Benzene and Substituted Benzenes

More About Amines Heterocylic Compounds

Carbohydrates

Amino Acids, Peptides, and Proteins

Catalysis

The Chemistry of Metabolism

Nucleosides, Nucleotides, and Nucleic Acids

Synthetic Polymers

Pericyclic Reactions

Filters

Propose a mechanism for the vitamin KH₂-catalyzed carboxylation of glutamate shown below:

Give the purpose of vitamin KH₂ as a coenzyme.

How does NAD⁺ serve as a catalyst in oxidation reactions?