Deck 5: Coenzymes

Question 1

Which labeled group is active in the redox function of the cofactor shown in Figure 5.1, and in which pathway is it most important?

A)Label I; transaminations.
B)Label II; tricarboxylic acid (TCA) cycle.
C)Label III; glycolysis.
D)Label IV; oxidative phosphorylation.
E)Label V; folate cycling.

Answer 1

Label IV; oxidative phosphorylation.

Question 2

Flavoproteins are proteins that contain:

A)Heme.
B)FAD or flavin mononucleotide (FMN).
C)Nicotinamide adenine dinucleotide (NAD) or nicotinamide adenine dinucleotide phosphate (NADP).
D)Zinc or copper.
E)Coenzyme A.

Answer 2

FAD or flavin mononucleotide (FMN).

Question 3

Coenzyme A has a very specific function in metabolic pathways.Its task is:

A)Transfer of hydrogen.
B)Transfer of electrons.
C)Attachment of carboxyl groups.
D)Activation of monosaccharides for the synthesis of complex carbohydrates.
E)Activation of organic acids.

Answer 3

Activation of organic acids.

Question 4

The cleavage of adenosine triphosphate (ATP) to adenosine monophosphate (AMP) + pyrophosphate is said to supply more energy than the cleavage of ATP to ADP + phosphate.Why?

A)ATP → ADP + phosphate cleaves a phosphoanhydride bond, and ATP → AMP + pyrophosphate cleaves a phosphodiester bond.
B)The cleavage to AMP and pyrophosphate is followed by the degradation of AMP by adenosine deaminase.
C)The cleavage to AMP and pyrophosphate is followed by the degradation of pyrophosphate.
D)ATP → ADP + phosphate cleaves a phosphoanhydride bond, and ATP → AMP + pyrophosphate cleaves a phosphate ester bond.
E)ATP → ADP + phosphate cleaves a phosphate ester bond, and ATP → AMP + pyrophosphate cleaves a phosphoanhydride bond.