Fermentation is a metabolic process that converts sugar to acids, gases, or alcohol. It occurs in yeast and bacteria, and also in oxygen-starved muscle cells, as in the case of lactic acid fermentation.
pupil noun [C] (EYE PART). âº the âcircular âblack âarea in the âcentre of an âeye, through which âlight âenters: Pupils âcontract in âbright âlight, and âdilate in darkness. (Definition of pupil from the Cambridge Advanced Learners Dictionary & Thesaurus Â© Cambridge University Press).
the opening in the center of the iris through which light enters the eye; see also Plate 17. Adie's pupil tonic pupil. Argyll Robertson pupil one that is miotic and responds to accommodation effort, but not to light. fixed pupil a pupil that does not react either to light or on convergence, or in accommodation.