An enzyme involved in the catabolism of fructose to pyruvate in the liver is:
**Core Concept**
The question is testing the student's knowledge of the metabolic pathway of fructose in the liver. The correct enzyme involved in the catabolism of fructose to pyruvate is part of the glycolytic pathway, which is crucial for energy production in the cell. The enzyme catalyzes a crucial step in the conversion of fructose-1-phosphate to glyceraldehyde and dihydroxyacetone phosphate.
**Why the Correct Answer is Right**
The correct enzyme is Aldolase B (Fructokinase is not the correct answer but is involved in the pathway), which is a key enzyme in the glycolytic pathway. It catalyzes the conversion of fructose-1,6-bisphosphate to glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. This step is essential for the further breakdown of fructose to pyruvate, which can then enter the citric acid cycle for energy production. Aldolase B is specifically expressed in the liver and is responsible for the catabolism of fructose.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Glucose-6-phosphatase is involved in the last step of gluconeogenesis and glycogenolysis, but not in the catabolism of fructose to pyruvate.
**Option B:** This option is incorrect because Phosphofructokinase is involved in the glycolytic pathway but is not the enzyme responsible for the catabolism of fructose to pyruvate.
**Option D:** This option is incorrect because Pyruvate kinase is also involved in the glycolytic pathway but is not the enzyme responsible for the catabolism of fructose to pyruvate.
**Clinical Pearl / High-Yield Fact**
Aldolase B deficiency is a rare genetic disorder that leads to the accumulation of fructose-1-phosphate in the liver, causing a range of symptoms including hypoglycemia, liver enlargement, and Fanconi syndrome.
**Correct Answer:** C. Aldolase B.