Biochemistry - MCQ Practice Questions

Which enzyme deficiency causes Essential Fructosuria, and why is it clinically benign?

Which carbohydrate metabolism enzyme is allosterically inhibited by citrate and ATP but activated by AMP and ADP?

In the glucose transporter classification, which GLUT protein is responsible for INSULIN-DEPENDENT glucose uptake in muscle and adipose tissue?

During starvation lasting 3-5 days, what is the PRIMARY source of glucose for the brain and RBCs?

In the non-oxidative phase of the pentose phosphate pathway, transketolase requires which cofactor?

Which enzyme catalyzes the first committed step of glycolysis and is inhibited by its end products ATP and citrate?

The Cori cycle operates between muscle and liver. Which of the following correctly describes the fate of lactate in the liver?

In the pentose phosphate pathway, which vitamin is required as a coenzyme for the oxidative phase?

Glycogen phosphorylase is activated during fight-or-flight response primarily through which mechanism?

In the glycolytic pathway, the enzyme that catalyzes substrate-level phosphorylation in the ATP-generating step is:

A patient with type 2 diabetes shows impaired glucose uptake in muscle tissue. Which GLUT isoform is primarily defective?

Which of the following statements about branching enzyme (α-1,6-glucosidase) is correct?

In the Rapoport-Luebering shunt of RBCs, 2,3-bisphosphoglycerate (2,3-BPG) is produced from which glycolytic intermediate?

During fasting state lasting 24-48 hours, which substrate becomes the predominant fuel source for the brain after glucose stores are depleted?

Which enzyme is inhibited by feedback inhibition from glucose-6-phosphate and is thus rate-limiting for glucose entry in liver?

In McArdle disease (GSD Type V), the enzyme deficient is glycogen phosphorylase. Which of the following is the most likely clinical presentation during exercise?

The oxidative phase of the pentose phosphate pathway produces NADPH. Which of the following is the primary biosynthetic use of NADPH?

Which statement best describes the relationship between glycogen structure and its metabolic advantages?

In the citric acid cycle, which carbohydrate-derived molecule enters directly after acetyl-CoA formation?

Which of the following conditions causes increased glycogenolysis in muscle tissue during exercise?