Consider the oxidation of ethanol (CH3CH2OH) to acetaldehyde (CH3CHO) by NAD+. a) write half reactions for the process. b) NADH is biochemical reducing agent, in the reverse of the oxidation reaction. Write half-reactions for the reduction of pyruvic acid(CH3COCOOH) to lactic acid (CH3CHOHCOOH) by NADH, and then combine these two to get the equation for overall reaction.