Biochemistry - MCQ Practice Questions

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

Which of the following is a ketohexose that is a structural isomer of glucose?

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?

Which disaccharide is formed by α-1,4-glycosidic linkage between glucose molecules?

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?

Which carbohydrate is a non-reducing sugar that cannot undergo mutarotation?

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?

Which of the following correctly pairs a glycogen storage disease with its enzyme defect and primary organ affected?

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

Which monosaccharide cannot be directly metabolized by red blood cells due to lack of specific enzymes?

In the Pasteur effect, the inhibition of glycolysis by oxidative phosphorylation is primarily mediated by which molecule(s)?

A newborn presents with jaundice, hepatomegaly, and infantile cataracts. Laboratory findings show elevated galactose in blood and urine. Which enzyme deficiency is most likely?

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

Which of the following carbohydrates is classified as a pentose sugar?