enzymes are usually composed of which type of molecule
Enzyme Enzymes are known to catalyze more than 5,000 biochemical reaction types.[4] Most enzymes are proteins, although a few are catalytic RNA molecules. The latter are called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures.
Acetylcholinesterase AChE is a hydrolase that hydrolyzes choline esters. It has a very high catalytic activity - each molecule of AChE degrades about 25000 molecules of acetylcholine (ACh) per second, approaching the limit allowed by diffusion of the substrate.[6][7] The active site of AChE comprises 2 subsites - the anionic site and the esteratic subsite. The structure and mechanism of action of AChE have been elucidated from the crystal structure of the enzyme.[8][9]