The principal regulatory factor governing the rate of the pentose phosphate pathway is the level of

Question

Quizplus · Accepted Answer

The pentose phosphate pathway is regulated by the level of NADP+ and NADPH. NADPH is an important reducing agent required for biosynthetic reactions and consequently, the demand for NADPH regulates the activity of the pentose phosphate pathway. NADP+ inhibits the enzyme glucose-6-phosphate dehydrogenase, which is the rate-limiting enzyme of the pentose phosphate pathway. Therefore, as the level of NADPH decreases, the concentration of NADP+ decreases and the enzyme is activated, leading to increased flux through the pathway. Hence, the best choice would be E, as it represents the levels of NADPH and NADP+.

The Principal Regulatory Factor Governing the Rate of the Pentose