2 Carbohydrates Carbohydrates are made from CARBON, HYDROGEN and OXYGEN They STORE ENERGY in plants and animalsPlant cell walls depend on the structural role of some carbohydratesCARBOHYDRATESMONOSACCHARIDESDISACCHARIDESPOLYSACCHARIDES
3 What does the ‘n’ stand for? formation of nucleic acid MonosaccharidesMonosaccharides are small organic molecules used as bulding blocks for more complex carbohydrates. Click each of the blue boxes to work through the slide.What does the ‘n’ stand for?General Formula(CH2O)nNumber of Carbon atomsTRIOSE, e.g. glyceraldehyde -In metabolic reactionsSo, when n=3When n=5When n=6PENTOSE, e.g. ribose –formation of nucleic acidHEXOSE, e.g. glucose -main source of energynext
4 Isomerism in Glucose C6H12O6 Alpha-glucoseCH2OHOxygenHydrogenCarbonHydroxide (OH)beta-glucoseShow structural changeCH2OH
5 DisaccharidesDisaccharides form when two monosaccharide units join forming a glycosidic bond, by a condensation reaction.A disaccharide can be made from two of the same monosaccharide molecule or from two different ones.The combination of monosaccharides determines which disaccharide is formed.MONOSACCHARIDESDISACCHARIDEGLUCOSEGLUCOSEGLUCOSEWATERWATERWATERSUCROSEMALTOSELACTOSEFRUCTOSEGALACTOSEGLUCOSE
6 Forming Disaccharides GlucoseCH2OHCOHOHCH2OHCOHOHCH2OHMaltoseCOHOHCH2OHOHOOHOHGlycosidicBondThis is a CONDENSATION reaction, where a water molecule is lost.
7 What is polymerisation ? PolysaccharidesPolysaccharides are large complex molecules known as POLYMERS.What is polymerisation ?What is a monomer?Click the bubble for the answerPolymerisation is the process of bonding many MONOMERS by condensation reactions to form one large molecule.Monomers are the individual monosaccharides which join to form the polysaccharide.MonomerGlycosidic bondAmyloseGlucose1-4PolysaccharidesGlycogenGlucose1-4 and 1-6Celluloseβ Glucose1-4NextReturn to isomerism of glucose
8 Forming polysaccharides GlucoseCH2OHCH2OHCH2OHCH2OHCOCOCOCOHHHHHHHHHHHHOHHOHHOHHOHHOHOHOHOHOHOHOOOOHOHOHOHOHHOHHOHHOHHOHIn this example, 3 condensation reactions have produced 3 water molecules to produce the polysaccharide.A HYDROLYSIS reaction (addition of water) reverses the reaction and splits the polysaccharide releasing 3 monosaccharide molecules.
9 You can give this question a go, in order to prove your understanding: