Maltases

Part of speech: noun

Definitions

1. Enzymes that catalyze the hydrolysis of maltose into glucose units contribute to carbohydrate digestion
2. Biological catalysts that facilitate the breakdown of maltose, a disaccharide, into its monosaccharide constituents
3. Proteins that speed up the conversion of maltose into glucose, playing a critical role in metabolic processes

Etymology: Maltase is a 19th-century coinage that follows the chemist's habit of naming enzymes after the substance they act on, and the "-ase" ending was settled on in the 1890s as a standard marker for enzymes. The stem comes from "malt", the Old English "mealt" (from the root meaning to soften or dissolve in water), combined with "-ose", the chemical suffix for sugars, which produced "maltose" in the mid-1800s for the sugar made when barley starch is broken down during malting. Maltase was the enzyme that finished the job, splitting that sugar into two glucose molecules. The plural "maltases" simply refers to more than one such enzyme. Chemists use the plural constantly because there are several distinct maltases, and they are often classed by source, such as those produced in the human small intestine or by yeast, which differ in structure and behaviour.