Question

Which of the following is false about HMP shunt?

• A. No ATP formation
• B. Formation of NADPH
• C. Synthesis of ribose - 5 - phosphate
• D. Non-oxidative phase of HMP pathway is irreversible

Answer 1

The Correct Option is D

To determine which statement about the HMP shunt is false, we must understand what the HMP (Hexose Monophosphate) shunt involves. The HMP shunt, also known as the pentose phosphate pathway, is an alternative pathway of glucose metabolism. It occurs in the cytosol and consists of two main phases: oxidative and non-oxidative.

1. No ATP formation: In the HMP shunt, no ATP is directly generated. This statement is true because the pathway's purpose is not to produce energy but to generate NADPH and ribose-5-phosphate.
2. Formation of NADPH: The primary purpose of the oxidative phase of the HMP shunt is to produce NADPH. NADPH is a crucial cofactor in biosynthetic pathways, including fatty acid synthesis. This statement is true.
3. Synthesis of ribose-5-phosphate: The HMP shunt also produces ribose-5-phosphate, which is essential for nucleotide synthesis. This statement is correct.
4. Non-oxidative phase of HMP pathway is irreversible: This statement is false. The non-oxidative phase of the HMP shunt is actually reversible. It plays a role in the interconversion of sugar phosphates. Thus, this option is the correct answer to the question as it is false about the HMP shunt.

Therefore, the correct answer is: Non-oxidative phase of HMP pathway is irreversible.