Direction of Oxidation-Reduction Reactions Which of the following reactions would you expect to proceed in the direction shown, under standard conditions, assuming that the appropriate enzymes are present to catalyze them? (a) Malate + NAD+oxaloacetate + NADH + H+ (b) Acetoacetate + NADH + H+ -hydroxybutyrate + NAD+ (e) Pyruvate + NADH + Hlactate + NAD+ (d) Pyruvate + B-hydroxybutyrate (e) Malate + pyruvate (f) Acetaldehyde + succinate lactate + acetoacetate oxaloacetate + lactate ethanol + fumarate