2024
Which of the following amino acids is considered non essential because it is
generated by the urea cycle?
A. arginine
B. lysine
C. asparagine
D. glutamine
E. histidine
arginine
The urea cycle takes place in which of the following subcellular locations?
A. the cytosol and the mitochondria
B. the mitochondria only
C. the cytosol only
the cytosol and the mitochondria
Ubiquitination is a means of targeting a protein for which of the following cellular
proceses?
A. Digestion
B. Proteasomal degradation
C. Storage
D. Protein translation
Proteasomal degradation
The reaction of ammonia with α-ketoglutarate is catalyzed by _________ and
requires _________ as a reactant.
A. glutamate dehydrogenase; ATP
B. glutamate dehydrogenase; NADH or NADPH
C. glutamate synthetase; NADH or NADPH
D. glutamate synthetase; ATP
,glutamate dehydrogenase; NADH or NADPH
Most enzymes involved in protein digestion require cleavage for activation. These
proteins are secreted as inactive protein forms called:
A. zymogens
B. unfolded polypeptides
C. dimers
D. activated forms
zymogens
Which of the following enzymes is regulated by N-acetyl glutamate (NAGs)?
A. CPS II
B. ornithine transcarbamylase
C. arginosuccinate lyase
D. CPS I
CPS I
Which of the following enzymes will be active in both the fed and fasted states?
A. Glutaminase
B. Pyruvate kinase
C. Hormone sensitive lipase
D. Glycogen synthase
Glutaminase
Which of the following enzymes is correctly paired with its activator?
A. N-acetylglutamate synthtase; arginine
B. Carbamoyl phosphate synthetase I; ATP
C. Glutaminase; citrate
D. arginase; NADH
N-acetylglutamate synthtase; arginine
Which of the following statements is consistent with nitrogen transport in the
fasted state?
A. Glutaminase will be active
, B. The urea cycle will be inactive
C. Hepatic glutamate dehydrogenase will primarily produce glutamate
D. Transport of alanine from skeletal muscle will be reduced.
Glutaminase will be active
In the case of a urea cycle deficiency, which of the following amino acids may
become essential?
A. glutamine
B. arginine
C. alanine
D. aspartate
arginine
The glucose alanine cycle is a method of transferring ammonia from the skeletal
muscle to the liver. In this process the non-toxic carrier of ammonia is which of
the following compounds?
A. glutamine
B. pyruvate
C. alanine
D. urea
alanine
Pepsinogen is activated by which of the following mechanisms or enzymes?
A. Pepsinogen is activated by trypsin
B. Pepsinogen is activated by enteropeptidase
C. A change in pH catalyzes the activation of pepsinogen to pepsin
D. Pepsinogen is activated by elastase
A change in pH catalyzes the activation of pepsinogen to pepsin
The process of autophagy is defined as which of the following processes?
A. Recycling of proteins under conditions of cellular need or starvation
B. Ubiquitin mediated protein degradation