NAD+

NAD stands for nicotinamide adenine dinucluotide. NAD⁺ is the oxidised form, and NADH is the reduced form, which exist in an equilibrium, with NAD⁺ being favoured. Oxidation of fuel molecules produces one hydrogen ion and two electrons^[1] which are used to reduce NAD⁺ in the reaction of ethanol + dehydrogenase to form ethanal + NADH + H⁺. Also NADH⁺ is oxidised to NAD in oxidative phosphoryation which is directly linked to ATP synthesis^[2].

References

1. ↑ Berg J.M., Stryer L., Tymoczko J.L. (2012) Biochemistry, 7th Edition, New York: W.H. Freeman and Company. p454
2. ↑ Alberts et al., 2008, Molecular Biology of the Cell,5th ed.,New York, Garland Science, Taylor and Francis Group p.86