乙酰胆碱酯酶 3D模型

This is an scientifically accurate representation of an enzyme in High Definition. Enzymes are proteins that catalyze (i.e., increase the rates of) chemical reactions. In enzymatic reactions, the molecules at the beginning of the process are called substrates, and the enzyme converts them into different molecules, called the products. Almost all processes in a biological cell need enzymes to occur at significant rates. Since enzymes are selective for their substrates and speed up only a few reactions from among many possibilities, the set of enzymes made in a cell determines which metabolic pathways occur in that cell. Acetylcholinesterase, also known as AChE, is an enzyme that degrades (through its hydrolytic activity) the neurotransmitter acetylcholine, producing choline and an acetate group. It is mainly found at neuromuscular junctions and cholinergic synapses in the central nervous system, where its activity serves to terminate synaptic transmission. AChE has a very high catalytic activity — each molecule of AChE degrades about 25000 molecules of acetylcholine per second. The choline produced by the action of AChE is recycled — it is transported, through reuptake, back into nerve terminals where it is used to synthesize new acetylcholine molecules.