Chapter 18 Lehninger biochemistry Test Bank Questions and Correct Answers.

Chapter 18 Lehninger biochemistry
Test Bank Questions and Correct
Answers.
1. Under which circumstances are amino acids not metabolized via oxidative degradation?



A) Starvation

B) Plants growing in nutrient-rich soils

C) Normal protein turnover

D) A diet rich in proteins

E) Uncontrolled diabetes - Answer B



2. 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



3. 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



4. Which of the following is a zymogen that can be converted to an endopeptidase that
hydrolyzes peptide bonds adjacent to Lys and Arg residues?

, D) Trypsin

E) Trypsinogen - Answer E



5. 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



6. The coenzyme required for all transaminations is derived from:



A) niacin.

B) pyridoxine (vitamin B6).

C) riboflavin.

D) thiamin.

E) vitamin B12. - Answer B



7. 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



8. Transamination from alanine to alpha-ketoglutarate requires the coenzyme:



A) biotin.

B) NADH.