Noun | 1. | coenzyme - a small molecule (not a protein but sometimes a vitamin) essential for the activity of some enzymes molecule - (physics and chemistry) the simplest structural unit of an element or compound cocarboxylase, thiamine pyrophosphate - a coenzyme important in respiration in the Krebs cycle coenzyme A - a coenzyme present in all living cells; essential to metabolism of carbohydrates and fats and some amino acids NAD, nicotinamide adenine dinucleotide - a coenzyme present in most living cells and derived from the B vitamin nicotinic acid; serves as a reductant in various metabolic processes NADP, nicotinamide adenine dinucleotide phosphate - a coenzyme similar to NAD and present in most living cells but serves as a reductant in different metabolic processes triphosphopyridine nucleotide - a coenzyme of several enzymes coenzyme Q, ubiquinone - any of several quinones found in living cells and that function as coenzymes that transfer electrons from one molecule to another in cell respiration |