Enzymes, vitamins and hormones can be classified into a single category of biological chemicals because of all of these
(a) enhance oxidative metabolism
(b) are conjugated proteins
(c) arc exclusively synthesised in the body of a living organism as at present
(d) help in regulating metabolism.
(d) Enzymes are protein that, in small amounts, speed up the rate of a biological reactions and help in regulating metabolism.
Hormones arc also metabolic regulator and help in stimulation or inhibition of one or more physiological processes.
Vitamines are accessory food factors which arc required in small quantity for controlling metabolism and body functioning.