Carbohydrates

• Monomers

  Smaller units from which larger molecules are made
• Polymers

  Molecules made from a large number of monomers joined together
• Examples of monomers

  Monosaccharides, amino acids and nucleotides
• Condensation reaction

  A reaction which joins two molecules together with the formation of a chemical bond and involves the elimination of a molecule of water
• Hydrolysis reaction

  A reaction which breaks a chemical bond between two molecules and involves the use of a water molecule
• All carbohydrates contain

  C, H and O
• Carbohydrate monomers

  Monosaccharides
• Examples of monosaccharides

  Glucose, fructose and galactose
• Monosaccharide

  Monomers from which larger carbohydrates are made
• Bond formed by the condensation of two monosaccharides

  Glycosidic bond
• Glucose is a _ sugar

  Hexose
• Isomers of glucose

  Alpha and beta
• Draw the isomers of glucose


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• Isomerism

  Molecules with the same molecular formula but a different arrangement of atoms
• Disaccharides

  Formed by the condensation of two monosaccharides
• Two alpha glucose

  Maltose
• Draw maltose


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• Glucose + fructose

  Sucrose
• Glucose + galactose

  Lactose
• Polysaccharides

  Formed by the condensation of many monosaccharides
• Components of glycogen

  Alpha glucose
• Components of starch

  Alpha glucose
• Components of cellulose

  Beta glucose
• Test for reducing sugars


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• Test for non-reducing sugars


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• Structure and functions of starch (6)

  Amylose = long, unbranched chain consisting of a coiled structure which is compact and good for storage

  Amylopectin = a long, branched chain consisting of many side branches which allow enzymes that break down the molecule access the glycosidic bonds easily - quicker release of glucose

  Insoluble in water - it doesn't affect water potential so water can't enter cells by osmosis (so they don't swell) - good storage
• Test for starch.


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• Structure and function of glycogen

  Branched - more ends for hydrolysing enzymes so glucose can be released quickly

  Compact structure - good for strorage
• Structure and function of cellulose

  Long, unbranched chains of beta glucose = linked together by hydrogen bonds to form micro fibrils which provide structural strength for plant cells