Carbohydrates and lipids

• The monosaccharides glucose, fructose, and galactose are the most common.
• Disaccharides are formed by condensation reactions between two monosaccharide molecules.
• Sucrose is made up of one molecule of glucose and one molecule of fructose.
• Lactose is made up of one molecule of glucose and one molecule of galactose.
• Starch is composed mainly of amylose (a linear polymer) and amylopectin (a branched polymer).
• Polysaccharides are long chains of monosaccharides joined together by glycosidic bonds.
• Glycogen is a storage form of glucose found in animals.
• Cellulose is an insoluble carbohydrate that forms the cell walls of plants.
• Unsaturated fatty acids contain at least one carbon-carbon double bond
• Triglycerides are formed when three fatty acid tails attach themselves to a glycerol backbone through ester linkages.
• a condensation reaction between 2 monosaccharides forms a glycosidic bond, making a disaccharide
• maltose is a disaccharide formed from the condensation of two glucose molecules
• glycogen and starch are formed by the condensation of alpha glucose
• cellulose is formed by the condensation of beta glucose molecules
• to test for reducing sugars(glucose + fructose) add Benedict's solution and put in hot water bath- positive result=orange precipitate
• when testing for non-reducing sugars(sucrose) add dilute HCL and place in hot water bath then add NaHCo2 to neutralise as well as Benedict's- positive result= red precipitate
• Triglycerides are formed by the condensation of one molecule of glycerol and three molecules of fatty acid.
• starch (amylopectin) has a helical structure meaning it is compact so more can be stored
• cellulose is a long unbranched molecule made from beta glucose, joined through hydrogen bonds, giving the molecule strength
• maltose, sucrose and lactose are 3 common disaccharides