3.3 (2.1.2) Carbohydrates

define carbohydrates

molecules that contain the elements carbon, hydrogen and oxygen only

why are glucose molecules polar and soluble in water

hydrogen bonds that form between the hydroxyl groups and water molecules

define glycosidic bond

a covalent bond formed between two glucose molecules

define condensation reaction

water is formed

examples of monosaccharides

glucose, fructose, galactose

glucose + glucose

maltose

glucose + fructose

sucrose

glucose + galactose

lactose

describe amylose

alpha 1,4-glycosidic bonds, helix structure, compact, unbranched

describe amylopectin

alpha 1,4-glycosidic bonds and alpha 1,6-glycosidic bonds, branched

describe starch

found only in plants, large, insoluble, used for storage of glucose, cannot enter or leave cells, no osmotic effect

describe glycogen

found in animals and fungi, large, insoluble, used for storage of glucose, cannot enter or leave cells, alpha 1,4-glycosidic bonds and alpha 1,6-glycosidic bonds, more branched than amylopectin, more compact

describe cellulose

beta glucose, cellulose fibres held together by hydrogen bonds, strong, chains lie parallel to each other, pectin embedded in between chains with microfibrils