NAD+ is an electron carrier. It carries high energy electrons to the Electron Transport Chain in cellular respiration. In the picture oxidation and reduction of this coenzyme is shown very well. The Cab represents the NADH molecule and the customers are electrons. In the first step, Hydrogen atoms with high energy electrons binds to NAD+. This reaction is reduction. NAD+ is reduced in the first step because it gains negatively charged electrons. Then, NADH molecule carries those electrons to last stage of cellular respiration. In the E.T.C. NADH molecule is oxidized to its original form by losing electrons. Also, this reaction produces energy.