These are two practical activities to enable students to investigate the substances plant cells are made of and the development of plants.

Practical activity 1: Sugar identification

This activity is intended as an introduction to the different polysaccharides that plants make, using wheat as a vehincle for introducing the structural and functional differences between starch and cellulose.

Wheat seeds contain starch in the endosperm (flour) and celllose mainly in the bran. By crushing wheat seeds students can separate the bran from the flour. They can then incubate both fractions of the wheat seesd with cellulase or amylase to investigate their breakdown. Cellulase should be able to digest only the bran while amylase should only digest the flour. Both digestions will produce glucose which can be proved by carrying out a Benedict's test, reinforcing this biochemical test for reducing sugars.