(Nelson, 2018) Chapter 1-28 | 9781464187964 | All Chapters
with Answers and Rationals
Which of these is not a protease that acts in the small intestine?
A) Chymotrypsin
B) Elastase
C) Enteropeptidase
D) Secretin
E) Trypsin - ANSWER: D
In the digestion of protein that occurs in the small intestine, which enzyme is critical in the activation
of zymogens?
A) Enteropeptidase
B) Hexokinase
C) Papain
D) Pepsin
E) Secretin - ANSWER: A
Which of the following is a zymogen that can be converted to an endopeptidase that hydrolyzes
peptide bonds adjacent to Lys and Arg residues?
A) Chymotrypsinogen
B) Pepsin
C) Pepsinogen
D) Trypsin
E) Trypsinogen - ANSWER: E
In amino acid catabolism, the first reaction for many amino acids is a(n):
A) decarboxylation requiring thiamine pyrophosphate (TPP).
B) hydroxylation requiring NADPH and O2.
C) oxidative deamination requiring NAD+.
D) reduction requiring pyridoxal phosphate (PLP).
E) transamination requiring pyridoxal phosphate (PLP). - ANSWER: E
The coenzyme required for all transaminations is derived from:
A) niacin.
B) pyridoxine (vitamin B6).
C) riboflavin.
D) thiamin.
E) vitamin B12. - ANSWER: B
The coenzyme involved in a transaminase reaction is:
A) biotin phosphate.
B) lipoic acid.
C) nicotinamide adenine dinucleotide phosphate (NADP+).
D) pyridoxal phosphate (PLP).
E) thiamine pyrophosphate (TPP). - ANSWER: D
Transamination from alanine to -ketoglutarate requires the coenzyme:
, A) biotin.
B) NADH.
C) No coenzyme is involved.
D) pyridoxal phosphate (PLP).
E) thiamine pyrophosphate (TPP). - ANSWER: D
Pyridoxal phosphate is a cofactor in this class of reactions:
A) acetylation.
B) desulfuration.
C) methylation.
D) reduction.
E) transamination. - ANSWER: E
Which of the following is not true of the reaction catalyzed by glutamate dehydrogenase?
A) It is similar to transamination in that it involves the coenzyme pyridoxal phosphate (PLP).
B) NH4+ is produced.
C) The enzyme can use either NAD+ or NADP+ as a cofactor.
D) The enzyme is glutamate-specific, but the reaction is involved in oxidizing other amino acids.
E) -Ketoglutarate is produced from an amino acid. - ANSWER: A
Glutamate is metabolically converted to -ketoglutarate and NH4+ by a process described as:
A) deamination.
B) hydrolysis.
C) oxidative deamination.
D) reductive deamination.
E) transamination. - ANSWER: C
The conversion of glutamate to an -ketoacid and NH4+:
A) does not require any cofactors.
B) is a reductive deamination.
C) is accompanied by ATP hydrolysis catalyzed by the same enzyme.
D) is catalyzed by glutamate dehydrogenase.
E) requires ATP. - ANSWER: D
Which of the following conversions require more than one step?
1. Alanine pyruvate
2. Aspartate oxaloacetate
3. Glutamate ketoglutarate
4. Phenylalanine hydroxyphenylpyruvate
5. Proline glutamate
A) 1 and 4
B) 1, 2, and 4
C) 1, 3, and 5
D) 2, 4, and 5
E) 4 and 5 - ANSWER: E
Urea synthesis in mammals takes place primarily in tissues of the:
A) brain.
B) kidney.