Because the molecules of organic matter are generally relatively large, acids or bases are needed as catalysts during hydrolysis, and sometimes biologically active enzymes are also used as catalysts.
In acidic aqueous solution, starch will be hydrolyzed into maltose, glucose, etc.; protein will be hydrolyzed into amino acids and other substances with relatively small molecular weights.
Starch granules will expand in hot water. Some of the starch will dissolve in the water, and the other part will be suspended in the water to form a gelatinous starch paste. After starch enters the human body, part of the starch is catalyzed by the amylase contained in saliva, causing a hydrolysis reaction to generate maltose.
The remaining starch continues to be hydrolyzed under the action of amylase secreted by the pancreas in the small intestine to generate maltose. Under the catalysis of maltase in the intestinal juice, maltose is hydrolyzed into glucose that can be absorbed by the human body to supply the nutritional needs of human tissues.
Extended information
Experimental method
1. Add 0.5g starch and 4ml water to test tube 1, add 0.5g starch and 4ml water to test tube 2 20 of sulfuric acid solution. Heat the test tubes respectively for 3~4 minutes.
2. Pour part of the solution in test tube 2 into test tube 3 and reserve it for the next experiment.
3. Add a few drops of iodine solution to test tube 1 and test tube 2 and observe the phenomenon. It was found that the solution in test tube 1 was blue (starch turned blue when exposed to iodine), but there was no obvious phenomenon in test tube 2.
4. Drop 10% sodium hydroxide solution into test tube 3 to adjust the pH value of the solution to about 9~10.
5. Take another test tube 4, add 3 ml of sodium hydroxide solution, and drop 4 drops of 2 copper sulfate solution into it. A blue copper hydroxide precipitate will immediately form. Then take 1 ml of the hydrolyzate in test tube 3 and drop it in. After shaking and mixing evenly, heat and boil with an alcohol lamp.
The color of the solution often varies from blue to yellow to green (a mixture of yellow and blue) to red. Eventually a red precipitate forms. The reason is that copper hydroxide is reduced to produce red cuprous oxide that is insoluble in water.
Reference: Baidu Encyclopedia - Starch Hydrolysis
Reference: Baidu Encyclopedia - Hydrolysis Reaction