The products of starch hydrolyzed by amylase are maltose and glucose.
As a result of the action of amylase, long sugar chains can be cut into short chains, that is, dextrins with smaller relative molecular weights are formed. The result of β-amylase is to cut off two glucose units, namely maltose, and the result of α-1,6 glycosidase is to cut off the side chain to form linear sugar. The function of glucose enzyme is to cut off glucose sequentially, and finally the starch can be completely hydrolyzed into glucose.
Starch is a macromolecular substance in which glucose is connected through sugar bonds. There are two types of starch: one is amylose, which is composed of glucose connected by a-1, 4 glycosidic bonds; the other is amylose, which is connected by a-1, 6-glucosidic bonds. Branched amylopectin is produced.
Amylose is unbranched and usually coiled into a spiral. It generally contains 50 to 250 glucose units and has a relative molecular mass of about 10,000-50,000. The amylopectin molecule contains approximately 250 to 500 glucose units, and the relative molecular mass is approximately 50 000 to 1 000 0000.
Extended information
Amylase classification:
amylase, Amy, AMS generally act on soluble starch, amylose, glycogen and other α-1,4 -Glucan, an enzyme that hydrolyzes α-1,4-glycosidic bonds. According to the different isomer types of enzyme hydrolysis products, it can be divided into α-amylase (EC3.2.1.1.) and β-amylase (EC3.2.1.2.).
1. Alpha-amylase is widely distributed in animals (saliva, pancreas, etc.), plants (malt, mountain spinach) and microorganisms. Microbial enzymes are almost always secreted. This enzyme uses Ca2 as an essential factor and serves as a stabilizing factor and activating factor. Some amylase is Ca2-independent.
2. β-amylase is widely distributed
The difference from α-amylase is that it cleaves α-1,4-glucan from the non-reducing end in units of maltose. sugar chain. Mainly found in higher plants (barley, wheat, sweet potato, soybean, etc.), but also reported to exist in bacteria, milk, and mold.
For unbranched substrates like amylose, maltose and a small amount of glucose can be completely decomposed. When acting on amylopectin or dextran, the previous reaction of cutting off the α-1,6-bond is stopped, so limit dextrin with a relatively large molecular weight is generated.
3. γ-amylase
Glucoamylase, glucoamylase, γ-amylase (γ-amylase) is an exonuclease that cleaves α from the non-reducing end of the starch molecule. (1→4) glycosidic bond and α(1→6) glycosidic bond.
The glucose residues are cut off one by one, similar to β-amylase, and the free hemiacetal hydroxyl group produced by hydrolysis undergoes translocation to release β-glucose. Regardless of whether it acts on amylose or amylopectin, the final product is glucose.
4. Isoamylase
Starch-1,6-glucosidase is produced by animals, plants, and microorganisms. Different sources have different names, such as: debranching enzyme, Q enzyme, R enzyme, pullulanase, pullulanase, etc.
Hydrolyze the α-1,6-glucosidic bond of amylopectin or glycogen to produce amylose (dextrin) of varying lengths. It is mainly produced by microbial fermentation, and the strains include yeast, bacteria and actinomycetes.
Baidu Encyclopedia-Starch Hydrolysis