(i) know the difference between monosaccharides, disaccharides and polysaccharides, including glycogen and starch (amylose and amylopectin)
(ii) be able to relate the structures of monosaccharides, disaccharides and polysaccharides to their roles in providing and storing energy β-glucose and cellulose are not required in this topic.
(iii) know how monosaccharides (glucose, fructose and galactose) join together to form disaccharides (maltose, sucrose and lactose) and polysaccharides (glycogen, amylose and amylopectin) through condensation reactions forming glycosidic bonds, and how these can be split through hydrolysis reactions
STARCH
• Spiral structure and insoluble nature
• It doesn’t diffuse across cell membranes
• Has very little osmotic effect within the cell
• Is a major source of energy for the diet
GLYCOGEN
• A polymer compound of glucose molecules
• Has numerous side branches= can be rapidly hydrolysed= easy access to stored energy
• In humans is found in liver and muscles
CELLULOSE
• Is a dietary fibre and is aka non-starch polysaccharide
• Made up of glucose molecules that are joined together= straight chain with no branches
• Glucose molecules have a slightly different structure than that of those in starch
• Has an important function in the movement of material through the digestive tract