Metabolism 

• 1878 in the physiology sense of "the sum of the chemical changes within the body by which the protoplasm is renewed, changed, or prepared for excretion," 

• from Greek metabole "a change," from metaballein "to change," from meta "change" + ballein "to throw".

Chemical 

• from chemic "of alchemy" (a worn-down derivative of Medieval Latin alchimicus) + -al (of or pertaining to).

Catabolic 

•  1876, katabolism, "destructive metabolism," 

• from Greek from kata "down" + ballein "to throw".

Anabolic

• "pertaining to the process of building up" (especially in metabolism), 1876, with -ic + Greek from ana "up, upward"  + ballein "to throw."

Reactant 

• 1640s, "to exert, as a thing acted upon, an opposite action upon the agent," from re- "back" + “act” from Latin actus, past participle of agere "to set in motion, drive, drive forward," hence "to do, perform,"

Product

• early 15c., "mathematical quantity obtained by multiplication," from Medieval Latin productum, in classical Latin "something produced," noun use of neuter past participle of producere "bring forth"

Endothermic

• Endo- word-forming element meaning "inside, within, internal," from Greek endon "in, within." 

•  from Greek therme "heat, feverish heat."

Exothermic

•  from Greek exō (adv.) "outside," related to ex (prep.) "out of" 

• from Greek therme "heat, feverish heat." 

Enzyme

• from Modern Greek enzymos "leavened," from en "in/within" + zymē "leaven" 

• En+zyme = “Leavened within/in”

• Hence, where we get leavened bread: substance, typically yeast, that is used in dough to make it rise.

Catalyst

• 1650s, "dissolution," 

• from Latinized form of Greek katalysis "dissolution, a dissolving" 

• from kata "down" (or "completely"), + lyein "to loosen"

Denaturation

• from Latin de "down, down from, from, off; concerning" (see de), also used as a prefix in Latin, usually meaning "down, off, away, from among, down from," (defenestration; the action of throwing someone out of a window.) 

• Fenestra (latin noun); window

• from Latin natura "course of things; natural character, constitution, quality; the universe," literally "birth," from natus "born," past participle of nasci "to be born,"

Consumer 

• from Latin consumere "to use up, eat, waste," from assimilated form of com-, here perhaps an intensive prefix + sumere "to take," 

• from sub- "under" + emere "to buy, take"

Carnivore 

•  from Latin carnivorus "flesh-eating" 

Omnivore

•  formed from omnivorous on model of carnivore/carnivorous. French omnivore was noted as a neologism in that language in 1801 and might be the direct source of the English word.

Aerobic 

• from Greek aero- "air" + bios "life" 

Anaerobic 

• from Greek an- "without" + aēr "air" + bios "life"