For each of the metabolic transformations, determine whether the compound on the left has undergone oxidation or reduction. Balance each transformation by inserting H-H and where necessary H2O.
a) C6H12O6 → 2C2H5OH + 2CO2
b) NADH + H+ + 1/2O2 → NAD+ + H2O
c) FADH2 + 1/2O2 → FAD+ + H2O
d) Lactate → Pyruvate + NADH + H+
