Biochemistry - MCQ Practice Questions

The disaccharide formed by α-glucose and β-fructose joined by α-1,2-glycosidic bond is:

Which enzyme catalyzes the reversible conversion of glucose-6-phosphate to fructose-6-phosphate?

A patient presents with inability to metabolize galactose. Which enzyme deficiency is most likely responsible for classical galactosemia?

The branching enzyme in glycogen synthesis catalyzes which type of reaction?

During high-intensity exercise, which carbohydrate provides immediate energy despite low concentration in blood?

Which of the following is NOT a function of glycogen in liver?

A newborn presents with hepatomegaly, lactic acidosis, and hypoglycemia. Enzyme analysis shows deficiency of glucose-6-phosphatase. Which disease is this?

In hereditary fructose intolerance (HFI), which enzyme deficiency causes accumulation of fructose-1-phosphate?

The optical rotation of freshly prepared glucose solution gradually decreases and reaches equilibrium. This phenomenon is called:

Which statement best explains the structural basis for the higher energy content of glucose compared to other hexoses?

A 6-year-old child presents with muscle pain and myoglobinuria after exercise. Muscle biopsy shows normal glycogen structure but elevated content. This is consistent with:

In the pentose phosphate pathway, the oxidative phase generates NADPH. Which metabolic process primarily utilizes this NADPH in fed state?

Which of the following carbohydrates does NOT undergo glycolysis?

A diabetic patient shows impaired glucose utilization despite high blood glucose. Which enzyme's activity is most likely reduced?

The Haworth projection of glucose differs from its Fischer projection. Which structural feature is best represented in Haworth projection?

During fasting, which hormonal change directly increases hepatic glycogenolysis?

Which adaptation occurs in liver during prolonged fasting to maintain blood glucose?

A patient with aldolase deficiency in fructose-1,6-bisphosphate (Class I aldolase) would show impaired glycolysis primarily because:

A 45-year-old patient with Type 2 diabetes mellitus shows elevated fasting blood glucose (180 mg/dL) but normal HbA1c levels initially. Which carbohydrate metabolism pathway is primarily impaired in this patient's liver?

In the non-oxidative phase of the pentose phosphate pathway, ribulose-5-phosphate is converted to ribose-5-phosphate by the enzyme ribulose-5-phosphate isomerase. Which tissue shows MAXIMUM activity of this pathway and why?