Metabolism of ethanol in the liver. Thickness and intensity of colour of arrow on left side of figure corresponds to extent of metabolic pathway followed (MEOS = Microsomal ethanol oxidizing system; ADH-alcohol dehydrogenase; ALDH = aldehyde dehydrogenase; NAD=nicotinamide adenine dinucleotide; NADH = reduced NAD; NADP = nicotinamide adenine dinucleotide phosphate; NADPH = reduced NADP).