Katabolism Ka*tab"o*lism, n. [Gr. ? down + ? to throw.] (Physiol.) Destructive or downward metabolism; regressive metamorphism; -- opposed to anabolism. See Disassimilation.
Metabolism Me*tab"o*lism, n. (Physiol.) The act or process, by which living tissues or cells take up and convert into their own proper substance the nutritive material brought to them by the blood, or by which they transform their cell protoplasm into simpler substances, which are fitted either for excretion or for some special purpose, as in the manufacture of the digestive ferments. Hence, metabolism may be either constructive (anabolism), or destructive (katabolism).