This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory chain, Subject name: Biochemistry
NADPH+, H+ is generated in the reaction catalysed by 
Select and explain. 
A. LDH, B. G-6 PD, C. G-3 PD, D. Alcohol dehydrogenase
B: G-6 PD
Answer: B: G-6 PD 
Explanation: Step 1 of HMP Pathway Glucose-6-phosphate is oxidized by NADP+ dependent Glucose-6-phosphate dehydrogenase (GPD). 6-phospho gluconolactone is formed. One molecule of NADPH is formed in the reaction (Fig. 10.1). This is the rate-limiting step. Regulation is affected by this enzyme.Ref: MN Chatterjea Textbook of Medical Biochemistry, 8th Edition, Page no: 113