BIO 101 1st EditionLecture 6Outline of Last LectureI. Intro to macromoleculesII. Dehydration SynthesisIII. Proteinsa. Amino acidsb. Polypeptide chainsIV. Levels of Protein Structurea. Primaryb. Secondaryc. Tertiaryd. QuaternaryOutline of Current LectureI. Carbohydratesa. Monosaccharidei. Ring structuresb. Disaccharidec. Polysaccharidei. Storageii. StructuralCarbohydratesSugars or polymers of sugarsMonomer= monosaccharide or sugarBond= glycosidic bondMonosaccharide (simplest monomer)Disaccharides (double sugar, 2 monomers joined by dehydration synthesis)Polysaccharides (storage: starch, glycogen) (structural: cellulose)Function primarily as energy source, energy storage, structural molecules, source of carbon to make other organic molecules)A). Monosaccharide- single sugarSugars contain C,H,O in fixed ration (CH20)3-7 carbons/sugar molecule- common ones [triose=3C, pentose=5C, hexose=6C]each carbon in sugar has a hydroxyl (-OH) group attatched to it, except one which is the carboxyl carbon (C=O)in H20 solution (like inside cells), these monosaccharides tend to form ring structures- reaction is reversible, but ring is favoredex: glucose (a specific hexose)BIO 101 1st EditionB). Disaccharides- 2 monosaccharides joined by a glycosidic bondEx: Maltose 2 glucoses joined by dehydration synthesis (important disaccharide used in brewing beer)In maltose, the glycoside bond joins C#1 of one glucose to C#4 of another glucoseOther disaccharides examples: glucose(6C) + galactoste lactose (milk sugar) Glucose (6C) + fructose(5C) sucrose (table sugar)C. Polysaccharides- macromolecules formed by linking 100s to 1000s of monosaccharide’s by glycosidic bonds1. Storage Polysaccharides- molecules used to store energy Ex: Starch= major storage polysaccharide in plants, a polymer of glucose connected by 1,4 glycosidic bondsWhat is a glycosidic bond? Glucose froms 2 inconvertible ring forms ( called and glucose), which differ in placement of –OH group on C#1, glucose has –OH BELOW plane of the ring -glucose has –OH above pane of the ringStarch is made of glucoses in the [ - form] 1, 4 bondsBIO 101 1st EditionMost animals have enzyme that catalyzes the chemical reaction to break this bond: can use starch as a source of energy.ex: Glycogen=major storage polysaccharide in animalspolymer of glucose, more branched than starchstored mostly in liver and muscle2. Structural Polysaccharides- help form a structureex: cellulose- forms structural reinforcement in plant cell wallslinear, unbranched polymer of glucose connected by 1,4 glycosidic bondspolymer similar to starch BUT most organisms cannot hydrolyze glucose monomers from celluloseWHY? Enzyme does not recognize 1,4 linkage (it looks different from 1,4 linkageex: Chitin- structural polysaccharide of an amino sugarforms the exoskeleton of arthropods (roach crunch)Form cell walls of some
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