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
"Reducing power" is usually in the form of: 
Select and explain. 
A. Reduced NADP+, B. Reduced NADPH, C. Reduced NAD, D. Oxidised NADH
A: Reduced NADP+
Answer: A: Reduced NADP+ 
Explanation: NADP?: Nicotinamide Adenine Dinucleotide Phosphate, is a diffusible electron carrier. Its reduced form (NADPH) is reducing power of the cell. A cells reservoir of NADPH represents its reducing power which is an impoant measure of cells usable energy. They store electrons until they are used in anabolic reactions. A cells reservoir of NADPH represents its reducing power which is an impoant measure of cells usable energy. Functions of NADPH: Synthesis of fatty acids, Synthesis of cholesterol, Fixation of ammonia by glutamate dehydrogenase, Oxidative metabolism by cytochrome P450 enzymes: - Generation of catecholamine mediators (dopamine, epinephrine and norepinephrine), - Drug metabolism, Generation of nitric oxide and reactive oxygen species by phagocytes, Scavenging of reactive oxygen species that form as byproducts of oxygen transpo and of the respiratory chain. Ref: Cell and Molecular Biology: Concepts and Experiments, By Gerald Karp, 6th Edition, Page 112