This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
In synthesis of fatty acids, energy is supplied by: 
Select and explain. 
A. NAD, B. NADPH, C. FAD, D. GTP
B: NADPH
Answer: B: NADPH 
Explanation: NADPH is involved in various reductive biosynthesis. NADPH is generated in HMP shunt pathway. In fattyacid synthesis each cycle of fattyacid synthesis requires 2 molecules of NADPH.