Oxidoreductase enzymes facilitate electron transfers in various ways, such as transferring a hydride and a proton, two electrons and two protons, or a hydrogen atom, an electron, and a proton. Proteins alone aren't typically efficient in catalyzing these reactions. Instead, coenzymes and cofactors play a crucial role in providing the necessary chemical reactions for oxidoreductase catalysis. Many of these enzymes specifically catalyze reactions where an alcoholic group is dehydrogenated to form an aldehyde or ketone, concurrently reducing NAD+ to NADH.