NAD+ + 2e+ + 2H+ → NADH + H+
FAD + 2e– + 2H+ → FADH2
When NAD+ (Nicotinamide Adenine Dinucleotide-oxidised form) and FAD (Flavin Adenine Dinucleotide) pick up electrons and one or two hydrogen ions (protons), they get reduced to NADH + H+ and FADH2 respectively. When they drop electrons and hydrogen off they go back to their original form. The reaction in which NAD+ and FAD gain (reduction) or lose (oxidation) electrons is called redox reaction (Oxidation-reduction reaction). These reactions are important in cellular respiration.
