nicotinamide adenine dinucleotide

Naturally occurring compound that acts as a coenzyme. It consists of two nucleotides, adenosine mononucleotide and nicotinamide mononucleotide, joined by a phosphate bridge. A similar compound, NAD phosphate, NADP, is produced by phosphorylating the ribose part of the adenosine mononucleotide. NAD takes part in oxidation–reduction reactions, being converted to NADH2 by accepting two hydrogen atoms. In this form it is able to enter the electron transport chain where it is oxidized back to NAD, producing large quantities of ATP in the process. NADP is an important oxidation–reduction factor in fatty acid biosynthesis.