Principle
Naturally occurring polymers like cellulose or starch can be decomposed into basic components (monomers). Starch is a polymer which is composed of glucose molecules as monomers and can be transformed into glucose again if it is hydrolyzed.Starch is a polysaccharide which is made up of 1 → 4-glycosidically linked α-glucose-molecules. The two forms of vegetable starches, amylose and amylopectin differ in their structure. Amylose is unbranched, due to the tetrahedral angles result a helical structure, in which iodine molecules are stored (blue coloration). Amylopectin has a branched structure due to the additional 1→6 glykosidic bond, and it is coloured reddish-violet by iodine. The detection with Fehling's solution is based on the reducing effect of the aldehyde group of glucose.

Learning objectives

•  Starch is a polymer and consists of glucose molecules

Benefits

• Easy teaching and efficient learning by using interactive experimentation PHYWE-Software
• Experiment is part of a complete solution set with experiments for the topic Chemistry of Polymers matched with international curriculum: all topics are covered