Which of he following enzyme is involved in the catabolism of fructose to pyruvate in the liver?
**Core Concept**
The catabolism of fructose to pyruvate in the liver involves a series of enzyme-mediated reactions that ultimately lead to the breakdown of fructose-1-phosphate and fructose-6-phosphate to pyruvate. This process is crucial for the metabolism of fructose, a monosaccharide that plays a significant role in carbohydrate metabolism.
**Why the Correct Answer is Right**
The correct answer is aldolase B, also known as fructose-1-phosphate aldolase. This enzyme catalyzes the cleavage of fructose-1-phosphate into glyceraldehyde and dihydroxyacetone phosphate, which are then further metabolized to pyruvate. Aldolase B is a key enzyme in the fructose catabolic pathway, and its deficiency can lead to hereditary fructose intolerance.
**Why Each Wrong Option is Incorrect**
**Option A:** Fructokinase is involved in the first step of fructose catabolism, where it phosphorylates fructose to form fructose-1-phosphate. However, it is not directly involved in the conversion of fructose-1-phosphate to pyruvate.
**Option B:** Glucose-6-phosphatase is an enzyme involved in glucose metabolism, where it catalyzes the dephosphorylation of glucose-6-phosphate to form glucose. It is not directly involved in fructose catabolism.
**Option C:** Phosphofructokinase is an enzyme involved in glycolysis, where it catalyzes the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate. While it is involved in the metabolism of fructose-6-phosphate, it is not directly involved in the catabolism of fructose to pyruvate.
**Clinical Pearl / High-Yield Fact**
Hereditary fructose intolerance is a rare genetic disorder caused by a deficiency of aldolase B. It is characterized by symptoms such as hypoglycemia, vomiting, and seizures after ingestion of fructose-containing foods.
**Correct Answer:** C. Aldolase B.