Question 1

In which of the following classes of reactions is a coenzyme required?

Accepted Answer

A) oxidation reactions 
B) two carbon transfer 
C) acyl transfer 
D) reduction reactions 
E) A, B, and D 
A) oxidation reactions 
B) two carbon transfer 
C) acyl transfer 
D) reduction reactions 
E) A, B, and D

Question 2

Which of the following is not needed for the pyruvate dehydrogenase system?

Accepted Answer

A) lipoate 
B) coenzyme A 
C) FAD 
D) NAD+ 
E) biotin 
A) lipoate 
B) coenzyme A 
C) FAD 
D) NAD+ 
E) biotin

Question 3

What structural feature of enzymes that catalyze redox reactions requires the presence of a coenzyme for reaction to occur?

Accepted Answer

An enzyme that catalyzes a red

Question 4

The common name of vitamin B1 is ________.

Accepted Answer

A) niacin 
B) riboflavin 
C) thiamine 
D) biotin 
E) panthothenate 
A) niacin 
B) riboflavin 
C) thiamine 
D) biotin 
E) panthothenate

Question 5

Give the products for the following reaction.

Accepted Answer

The answer of Give the products for the following reaction....

Question 6

Which of the following statements is/are true about the vitamin KH2?

Accepted Answer

A) It is the active coenzyme form of vitamin K. 
B) Vitamin K is a quinone while vitamin KH2 is a hydroquinone. 
C) Vitamin KH2 is the coenzyme for the enzyme that catalyzes the carboxylation of glutamate side chains in proteins to form Å-carboxyglutamates. 
D) A and C 
E) A, B, and C 
A) It is the active coenzyme form of vitamin K. 
B) Vitamin K is a quinone while vitamin KH2 is a hydroquinone. 
C) Vitamin KH2 is the coenzyme for the enzyme that catalyzes the carboxylation of glutamate side chains in proteins to form Å-carboxyglutamates. 
D) A and C 
E) A, B, and C

Question 7

Which of the following is/are water-soluble vitamins?

Accepted Answer

A) vitamin B12 
B) riboflavin (vitamin B2) 
C) thiamine (vitamin B1) 
D) pyridoxine (vitamin B6) 
E) all of the above 
A) vitamin B12 
B) riboflavin (vitamin B2) 
C) thiamine (vitamin B1) 
D) pyridoxine (vitamin B6) 
E) all of the above

Question 8

Vitamin B2 is used to form the coenzyme(s)________.

Accepted Answer

A) NAD+ and NADH 
B) FAD and FADH2 
C) TTP 
D) CoASH 
E) THF 
A) NAD+ and NADH 
B) FAD and FADH2 
C) TTP 
D) CoASH 
E) THF

Question 9

Give the products for the following reaction.

Accepted Answer

The answer of Give the products for the following reaction....

Question 10

Which of the following statements is not true about the structure of vitamin B12?

Accepted Answer

A) The structure was determined by Dorothy Hodgkin in 1955 using X-ray crystallography. 
B) The structure has an adenosyl group. 
C) The structure has a cyano group, HO-, or H2O. 
D) The cyano group is coordinated to cobalt. 
E) The structure cannot be synthesized by plants and animals. 
A) The structure was determined by Dorothy Hodgkin in 1955 using X-ray crystallography. 
B) The structure has an adenosyl group. 
C) The structure has a cyano group, HO-, or H2O. 
D) The cyano group is coordinated to cobalt. 
E) The structure cannot be synthesized by plants and animals.

Question 11

How does CoASH used in biological systems to activate carboxylic acids?

Accepted Answer

A) converts carboxylic acids into amides 
B) converts carboxyic acids into anhydrides 
C) converts carboxylic acids into acid halides 
D) converts carboxylic acids into thioesters 
E) converts carboxylic acids into esters 
A) converts carboxylic acids into amides 
B) converts carboxyic acids into anhydrides 
C) converts carboxylic acids into acid halides 
D) converts carboxylic acids into thioesters 
E) converts carboxylic acids into esters

Question 12

Identify the first step in the mechanism for the vitamin KH2-dependent carboxylation of glutamate.

Accepted Answer

A) The vitamin K base removes a proton from the gamma-carbon of the gluatamate. 
B) The vitamin loses a proton from a phenolic OH group. 
C) The dioxetane collapses to form a vitamin K base. 
D) The base attacks molecular oxygen. 
E) The glutamate carbanion attacks carbon dioxide. 
A) The vitamin K base removes a proton from the gamma-carbon of the gluatamate. 
B) The vitamin loses a proton from a phenolic OH group. 
C) The dioxetane collapses to form a vitamin K base. 
D) The base attacks molecular oxygen. 
E) The glutamate carbanion attacks carbon dioxide.

Question 13

What are the main structural and functional differences between NAD+/NADH and NADP+/NADPH?

Accepted Answer

The only way in which NADP⁺ differs struc

Question 14

Which of the following reactions is called an α, β-elimination of an amino acid?

Accepted Answer

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

Question 15

Propose a mechanism for the following reaction.

Accepted Answer

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

Question 16

What are the products obtained from the reaction of NADH with FMN catalyzed by NADH dehydrogenase as shown below? NADH
NADH + FMN   ? + ?

Accepted Answer

A) NAD+ + FMNH2 
B) NAD+ + FMNH 
C) NAF + DHN 
D) NAF + DNH2 
E) N2A2D2 + FMNH2 
A) NAD+ + FMNH2 
B) NAD+ + FMNH 
C) NAF + DHN 
D) NAF + DNH2 
E) N2A2D2 + FMNH2

Question 17

What is the major organic product of this oxidation-reduction reaction?

Accepted Answer

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

Question 18

Which of the following statements is not true of coenzymes?

Accepted Answer

A) Coenzymes catalyze chemical reactions similar to enzymes. 
B) Coenzymes may function as oxidizing and reducing agents. 
C) Coenzymes play a variety of chemical roles exactly like those played by the amino acid side chains of enzymes. 
D) Coenzymes may function as nucleophiles or strong bases needed in a reaction. 
E) Coenzymes may function as activators needed in a reaction. 
A) Coenzymes catalyze chemical reactions similar to enzymes. 
B) Coenzymes may function as oxidizing and reducing agents. 
C) Coenzymes play a variety of chemical roles exactly like those played by the amino acid side chains of enzymes. 
D) Coenzymes may function as nucleophiles or strong bases needed in a reaction. 
E) Coenzymes may function as activators needed in a reaction.

Question 19

What is the first reaction in the catabolism of most amino acids?

Accepted Answer

A) transamination 
B) decarboxylation 
C) phosphorylation 
D) aldolation 
E) ligation 
A) transamination 
B) decarboxylation 
C) phosphorylation 
D) aldolation 
E) ligation

Question 20

A deficiency of ________ results in megoblastic anemia.

Accepted Answer

A) folic acid 
B) thiamine 
C) niacin 
D) riboflavin 
E) vitamin D 
A) folic acid 
B) thiamine 
C) niacin 
D) riboflavin 
E) vitamin D

Exam 24: The Organic Mechanisms of the Coenzymes

In which of the following classes of reactions is a coenzyme required?

Which of the following is not needed for the pyruvate dehydrogenase system?

What structural feature of enzymes that catalyze redox reactions requires the presence of a coenzyme for reaction to occur?

The common name of vitamin B1 is ________.

Give the products for the following reaction.

Which of the following statements is/are true about the vitamin KH2?

Which of the following is/are water-soluble vitamins?

Vitamin B2 is used to form the coenzyme(s)________.

Give the products for the following reaction.

Which of the following statements is not true about the structure of vitamin B12?

How does CoASH used in biological systems to activate carboxylic acids?

Identify the first step in the mechanism for the vitamin KH2-dependent carboxylation of glutamate.

What are the main structural and functional differences between NAD+/NADH and NADP+/NADPH?

Which of the following reactions is called an α, β-elimination of an amino acid?

Propose a mechanism for the following reaction.

What are the products obtained from the reaction of NADH with FMN catalyzed by NADH dehydrogenase as shown below? NADH NADH + FMN ? + ?

What is the major organic product of this oxidation-reduction reaction?

Which of the following statements is not true of coenzymes?

What is the first reaction in the catabolism of most amino acids?

A deficiency of ________ results in megoblastic anemia.

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

The common name of vitamin B₁ is ________.

Which of the following statements is/are true about the vitamin KH₂?

Vitamin B₂ is used to form the coenzyme(s)________.

Which of the following statements is not true about the structure of vitamin B₁₂?

Identify the first step in the mechanism for the vitamin KH₂-dependent carboxylation of glutamate.

What are the main structural and functional differences between NAD⁺/NADH and NADP⁺/NADPH?