Which of the following enzyme is a constituent of HMP shunt-
**Core Concept**
The Hexose Monophosphate (HMP) shunt, also known as the pentose phosphate pathway, is a metabolic pathway that generates NADPH and pentoses from glucose-6-phosphate. This pathway plays a crucial role in the biosynthesis of nucleotides, fatty acids, and cholesterol, as well as in the regulation of oxidative stress and inflammation.
**Why the Correct Answer is Right**
The correct answer is Glucose-6-phosphate dehydrogenase (G6PD). This enzyme catalyzes the first step of the HMP shunt, converting glucose-6-phosphate into 6-phosphoglucono-1,5-lactone, producing NADPH in the process. G6PD is a key enzyme in this pathway, as it generates the reducing power necessary for the subsequent reactions. The NADPH produced in this pathway is essential for maintaining the balance between oxidative stress and antioxidant defenses in cells.
**Why Each Wrong Option is Incorrect**
**Option A:** Glucokinase is an enzyme involved in the glycolytic pathway, catalyzing the conversion of glucose to glucose-6-phosphate. While it is involved in glucose metabolism, it is not a constituent of the HMP shunt.
**Option B:** Phosphofructokinase-1 is a key regulatory enzyme in the glycolytic pathway, catalyzing the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate. It is not directly involved in the HMP shunt.
**Option C:** Pyruvate kinase is another enzyme in the glycolytic pathway, catalyzing the final step of glycolysis, converting phosphoenolpyruvate to pyruvate. It is not a constituent of the HMP shunt.
**Clinical Pearl / High-Yield Fact**
G6PD deficiency is a genetic disorder that affects the enzyme G6PD, leading to a deficiency of this enzyme. This deficiency can cause hemolytic anemia, particularly in response to oxidative stress, such as exposure to certain medications or foods.
**Correct Answer:** C. Glucose-6-phosphate dehydrogenase.