Catalyst - a substance which alters the rate of a reaction without itself undergoing any permanent chemical changes

Contact process - an industrial process which manufactures sulphuric acid; during the production vanadium(V) oxide is used as catalyst to manufacture sulphur trioxide

Effective collision - a collision is effective when particles collide in the right orientation and the colliding particles acquire enough energy for bond breaking and bond formation

Enzyme - biological catalyst that appears in nature

Fermentation - a slow breakdown of large organic molecules into small molecules by microorganisms in the absence of oxygen

Haber process - an industrial process which uses iron as catalyst to manufacture ammonia gas

Orientation - describe the direction and position

Yeast - a type of enzyme that can catalyze fermentation