-carbohydrates contain carbon , hydrogen and oxygen -also known as saccharides -glucose is a hexose monosaccharide (composed of 6 carbons ) -two structural variations: alpha α and beta β glucose ,in which the OH group on carbon 1 is in opposite positions - glucose : polar and soluble in water due to the bonds that form between the hydroxyl groups and water molecules -glycosidic bond : bond formed between two glucose molecules by a condensation reaction forming a disaccharide -fructose +galactose =sucrose -galactose +glucose = lactose - starch :many alpha glucose molecules can be joined by glycosidic bonds to form two slightly different polysaccharides - one of the polysaccharides of starch is called amylose - amylose : formed by alpha glucose molecules joined together only by 1-4 glycosidic bonds -amylopectin: both 1-4 and 1-6 (every 25 glucose subunits )glycosidic bonds between alpha glucose molecules. 1-6 glycosidic bonds cause branching -glycogen : more branches than amylopectin . Compact so ideal for storage . Speeds up the process of storing and releasing glucose molecules required in the cell.Insoluble -hydrolysis reactions opposite of condensation reaction -cellulose:beta glucose molecules. Join together by alternate beta glucose molecules turn upside down - straight chain molecule: cellulose -cellulose molecules make H bonds with each-other forming microfibrils. Microfibrils join together to form macrofibrils which combine to produce fibres
