BIOCHEM 210 EXAM /APPROVED BIOCHEM 210 FINAL EXAM
ACTUAL 2026/2027 TEST BANK AND COMPREHENSIVE
PRACTICE QUESTIONS COMPLETE ACCURATE EXAM REAL
QUESTIONS WITH WELL ELABORATED ANSWERS AND
DETAILED RATIONALES (100% CORRECT VERIFIED
SOLUTIONS) CURRENTLY UPDATED VERSION 2026 EDITION
|GUARANTEED PASS A+ |INSTANT DOWNLOAD PDF |JUST
RELEASED
1. Which of the following best describes the primary function of the
enzyme glycogen phosphorylase?
A) Synthesis of glycogen from UDP-glucose
B) Cleavage of α(1→6) glycosidic bonds in glycogen
C) Phosphorolytic cleavage of α(1→4) glycosidic bonds in glycogen
D) Hydrolysis of glucose-6-phosphate to glucose
E) Transfer of a glucosyl residue to the non-reducing end
Correct Answer: C) Phosphorolytic cleavage of α(1→4) glycosidic
bonds in glycogen
Rationale: Glycogen phosphorylase catalyzes the rate-limiting step in
glycogen degradation. It uses inorganic phosphate to cleave the
α(1→4) glycosidic bonds at the non-reducing ends of glycogen,
,producing glucose-1-phosphate. Option A describes glycogen
synthase. Option B describes the debranching enzyme. Option D
describes glucose-6-phosphatase. Option E describes the action of
glycogen synthase.
2. A patient presents with severe lactic acidosis following strenuous
exercise. Which of the following enzymes is most directly
responsible for the production of lactate in this scenario?
A) Pyruvate dehydrogenase
B) Lactate dehydrogenase
C) Pyruvate carboxylase
D) Phosphofructokinase-1
E) Alcohol dehydrogenase
Correct Answer: B) Lactate dehydrogenase
Rationale: During strenuous exercise, oxygen supply to muscles
becomes limiting. The electron transport chain cannot keep up,
leading to a buildup of NADH. Lactate dehydrogenase (LDH)
regenerates NAD+ by reducing pyruvate to lactate, allowing
glycolysis to continue. Option A converts pyruvate to acetyl-CoA
under aerobic conditions. Option C converts pyruvate to
oxaloacetate for gluconeogenesis. Option D is a key regulatory
enzyme of glycolysis.
,3. In the context of fatty acid synthesis, which molecule is the
primary carrier of the acetyl group from the mitochondria to the
cytosol?
A) Acetyl-CoA
B) Citrate
C) Malonyl-CoA
D) Carnitine
E) Oxaloacetate
Correct Answer: B) Citrate
Rationale: Acetyl-CoA is produced in the mitochondria but fatty
acid synthesis occurs in the cytosol. Acetyl-CoA cannot cross the
mitochondrial membrane directly. It is first condensed with
oxaloacetate to form citrate, which is then transported to the cytosol
via the citrate shuttle. In the cytosol, citrate is cleaved by ATP-citrate
lyase to regenerate acetyl-CoA and oxaloacetate. Malonyl-CoA is
the activated two-carbon donor for the fatty acid synthase complex.
4. Which of the following is a key allosteric activator of pyruvate
kinase in glycolysis?
A) ATP
B) Acetyl-CoA
, C) Fructose-1,6-bisphosphate
D) Glucose-6-phosphate
E) Citrate
Correct Answer: C) Fructose-1,6-bisphosphate
Rationale: Fructose-1,6-bisphosphate is a positive allosteric effector
of pyruvate kinase, the enzyme that catalyzes the final step of
glycolysis. This represents a form of feed-forward activation, where
an intermediate produced earlier in the pathway stimulates a
downstream enzyme, promoting efficient glucose metabolism. ATP,
acetyl-CoA, and citrate are all negative regulators (inhibitors) of
various glycolytic enzymes. Glucose-6-phosphate is a feedback
inhibitor of hexokinase.
5. The enzyme that catalyzes the conversion of glucose-6-phosphate
to glucose, a key step in maintaining blood glucose homeostasis, is
primarily found in which organ?
A) Skeletal muscle
B) Adipose tissue
C) Liver
D) Brain
E) Heart
ACTUAL 2026/2027 TEST BANK AND COMPREHENSIVE
PRACTICE QUESTIONS COMPLETE ACCURATE EXAM REAL
QUESTIONS WITH WELL ELABORATED ANSWERS AND
DETAILED RATIONALES (100% CORRECT VERIFIED
SOLUTIONS) CURRENTLY UPDATED VERSION 2026 EDITION
|GUARANTEED PASS A+ |INSTANT DOWNLOAD PDF |JUST
RELEASED
1. Which of the following best describes the primary function of the
enzyme glycogen phosphorylase?
A) Synthesis of glycogen from UDP-glucose
B) Cleavage of α(1→6) glycosidic bonds in glycogen
C) Phosphorolytic cleavage of α(1→4) glycosidic bonds in glycogen
D) Hydrolysis of glucose-6-phosphate to glucose
E) Transfer of a glucosyl residue to the non-reducing end
Correct Answer: C) Phosphorolytic cleavage of α(1→4) glycosidic
bonds in glycogen
Rationale: Glycogen phosphorylase catalyzes the rate-limiting step in
glycogen degradation. It uses inorganic phosphate to cleave the
α(1→4) glycosidic bonds at the non-reducing ends of glycogen,
,producing glucose-1-phosphate. Option A describes glycogen
synthase. Option B describes the debranching enzyme. Option D
describes glucose-6-phosphatase. Option E describes the action of
glycogen synthase.
2. A patient presents with severe lactic acidosis following strenuous
exercise. Which of the following enzymes is most directly
responsible for the production of lactate in this scenario?
A) Pyruvate dehydrogenase
B) Lactate dehydrogenase
C) Pyruvate carboxylase
D) Phosphofructokinase-1
E) Alcohol dehydrogenase
Correct Answer: B) Lactate dehydrogenase
Rationale: During strenuous exercise, oxygen supply to muscles
becomes limiting. The electron transport chain cannot keep up,
leading to a buildup of NADH. Lactate dehydrogenase (LDH)
regenerates NAD+ by reducing pyruvate to lactate, allowing
glycolysis to continue. Option A converts pyruvate to acetyl-CoA
under aerobic conditions. Option C converts pyruvate to
oxaloacetate for gluconeogenesis. Option D is a key regulatory
enzyme of glycolysis.
,3. In the context of fatty acid synthesis, which molecule is the
primary carrier of the acetyl group from the mitochondria to the
cytosol?
A) Acetyl-CoA
B) Citrate
C) Malonyl-CoA
D) Carnitine
E) Oxaloacetate
Correct Answer: B) Citrate
Rationale: Acetyl-CoA is produced in the mitochondria but fatty
acid synthesis occurs in the cytosol. Acetyl-CoA cannot cross the
mitochondrial membrane directly. It is first condensed with
oxaloacetate to form citrate, which is then transported to the cytosol
via the citrate shuttle. In the cytosol, citrate is cleaved by ATP-citrate
lyase to regenerate acetyl-CoA and oxaloacetate. Malonyl-CoA is
the activated two-carbon donor for the fatty acid synthase complex.
4. Which of the following is a key allosteric activator of pyruvate
kinase in glycolysis?
A) ATP
B) Acetyl-CoA
, C) Fructose-1,6-bisphosphate
D) Glucose-6-phosphate
E) Citrate
Correct Answer: C) Fructose-1,6-bisphosphate
Rationale: Fructose-1,6-bisphosphate is a positive allosteric effector
of pyruvate kinase, the enzyme that catalyzes the final step of
glycolysis. This represents a form of feed-forward activation, where
an intermediate produced earlier in the pathway stimulates a
downstream enzyme, promoting efficient glucose metabolism. ATP,
acetyl-CoA, and citrate are all negative regulators (inhibitors) of
various glycolytic enzymes. Glucose-6-phosphate is a feedback
inhibitor of hexokinase.
5. The enzyme that catalyzes the conversion of glucose-6-phosphate
to glucose, a key step in maintaining blood glucose homeostasis, is
primarily found in which organ?
A) Skeletal muscle
B) Adipose tissue
C) Liver
D) Brain
E) Heart
