Because the molecules of organic matter are generally large, hydrolysis requires acids or bases as catalysts, and sometimes biologically active enzymes are used as catalysts. In acidic aqueous solutions starch is hydrolyzed to maltose, glucose, etc.; proteins are hydrolyzed to amino acids and other substances with smaller molecular weights. In hot water the starch granules swell, with some of the starch dissolved in the water and the other part suspended in the water, forming a gelatinous starch paste. After the starch enters the body, a portion of the starch is catalyzed by the amylase enzyme contained in the saliva, a hydrolysis reaction occurs, generating maltose.

Experimental Methods:

1. Add 0.5g of starch and 4ml of water to test tube 1, and add 0.5g of starch and 4ml of 20% sulfuric acid solution to test tube 2. Heat the test tubes separately for 3~4 min.

2. Pour part of the solution in test tube 2 into test tube 3 and keep 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 in color (starch turns blue when it meets iodine) and there was no significant phenomenon in test tube 2.

4, to the test tube 3 drops of 10% sodium hydroxide solution, adjust the pH of the solution is about 9 ~ 10.

5, another test tube 4 to add 3 ml of sodium hydroxide solution, and to which 4 drops of 2% copper sulfate solution, there is immediately a blue precipitate of copper hydroxide generated. Then take a test tube 3 in the hydrolyzed solution 1ml drops, oscillate and mix well, and then heat with an alcohol lamp to boil.

The solution color is often blue - yellow - green (yellow and blue mixed) - red and a series of changes. Eventually there is a red precipitate. The reason is that copper hydroxide is reduced to produce red insoluble cuprous oxide.