Chapter 5Overview: The Molecules of LifeConcept 5.1: Most macromolecules are polymers, built from monomersThe Synthesis and Breakdown of PolymersLE 5-2The Diversity of PolymersConcept 5.2: Carbohydrates serve as fuel and building materialSugarsLE 5-3Slide 10LE 5-4Slide 12LE 5-5PolysaccharidesStorage PolysaccharidesLE 5-6aSlide 17LE 5-6bStructural PolysaccharidesLE 5-7Slide 21LE 5-8Slide 23Slide 24Slide 25Slide 26Concept 5.3: Lipids are a diverse group of hydrophobic moleculesFatsLE 5-11aSlide 30LE 5-11bSlide 32Slide 33LE 5-12aSlide 35LE 5-12bPhospholipidsLE 5-13Slide 39LE 5-14SteroidsSlide 42Anabolic steroidsConcept 5.4: Proteins have many structures, resulting in a wide range of functionsSlide 45FUNCTIONS OF PROTEINSSlide 47LE 5-16PolypeptidesAmino Acid MonomersLE 5-UN78LE 5-17aLE 5-17bLE 5-17cAmino Acid PolymersDetermining the Amino Acid Sequence of a PolypeptideProtein Conformation and FunctionLE 5-19Four Levels of Protein StructureLE 5-20Slide 61LE 5-20aSlide 63LE 5-20bSlide 65LE 5-20dSlide 67LE 5-20eSickle-Cell Disease: A Simple Change in Primary StructureLE 5-21aLE 5-21bWhat Determines Protein Conformation?LE 5-22The Protein-Folding ProblemLE 5-23aLE 5-23bSlide 77LE 5-24aLE 5-24bConcept 5.5: Nucleic acids store and transmit hereditary informationThe Roles of Nucleic AcidsLE 5-25The Structure of Nucleic AcidsLE 5-26aNucleotide MonomersLE 5-26bNucleotide PolymersThe DNA Double HelixLE 5-27DNA and Proteins as Tape Measures of EvolutionThe Theme of Emergent Properties in the Chemistry of Life: A ReviewCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsPowerPoint Lectures for Biology, Seventh EditionNeil Campbell and Jane ReeceLectures by Chris RomeroChapter 5Chapter 5The Structure and Function of MacromoleculesCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsOverview: The Molecules of Life•Within cells, small organic molecules are joined together to form larger molecules•Macromolecules are large molecules composed of thousands of covalently connected atomsCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsConcept 5.1: Most macromolecules are polymers, built from monomers•A polymer is a long molecule consisting of many similar building blocks called monomers•Three of the four classes of life’s organic molecules are polymers:–Carbohydrates–Proteins–Nucleic acidsCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsThe Synthesis and Breakdown of Polymers•Monomers form larger molecules by condensation reactions called dehydration reactions•Polymers are disassembled to monomers by hydrolysis, a reaction that is essentially the reverse of the dehydration reactionLE 5-2LE 5-2Short polymerUnlinked monomerDehydration removes a watermolecule, forming a new bondDehydration reaction in the synthesis of a polymerLonger polymerHydrolysis adds a watermolecule, breaking a bondHydrolysis of a polymerCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsThe Diversity of Polymers•Each cell has thousands of different kinds of macromolecules •Macromolecules vary among cells of an organism, vary more within a species, and vary even more between species•An immense variety of polymers can be built from a small set of monomers123HOHCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsConcept 5.2: Carbohydrates serve as fuel and building material•Carbohydrates include sugars and the polymers of sugars•The simplest carbohydrates are monosaccharides, or single sugars•Carbohydrate macromolecules are polysaccharides, polymers composed of many sugar building blocksCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsSugars•Monosaccharides have molecular formulas that are usually multiples of CH2O•Glucose is the most common monosaccharide•Monosaccharides are classified by location of the carbonyl group and by number of carbons in the carbon skeletonLE 5-3LE 5-3Triose sugars(C3H6O3)GlyceraldehydeAldosesKetoses Pentose sugars(C5H10O5)RiboseHexose sugars(C5H12O6)GlucoseGalactoseDihydroxyacetoneRibuloseFructoseCopyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings•Monosaccharides serve as a major fuel for cells and as raw material for building molecules •Though often drawn as a linear skeleton, in aqueous solutions they form ringsLE 5-4LE 5-4Linear andring formsAbbreviated ringstructureCopyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings•A disaccharide is formed when a dehydration reaction joins two monosaccharides •This covalent bond is called a glycosidic linkageLE 5-5LE 5-5GlucoseMaltoseFructoseSucroseGlucoseGlucoseDehydrationreaction in thesynthesis of maltoseDehydrationreaction in thesynthesis of sucrose1–4glycosidiclinkage1–2glycosidiclinkageCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsPolysaccharides•Polysaccharides, the polymers of sugars, have storage and structural roles•The structure and function of a polysaccharide are determined by its sugar monomers and the positions of glycosidic linkagesCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsStorage Polysaccharides•Starch, a storage polysaccharide of plants, consists entirely of glucose monomers•Plants store surplus starch as granules within chloroplasts and other plastidsLE 5-6aLE 5-6aChloroplast Starch1 µmAmyloseStarch: a plant polysaccharideAmylopectinCopyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings•Glycogen is a storage polysaccharide in animals•Humans and other vertebrates store glycogen mainly in liver and muscle cellsLE 5-6bLE 5-6bMitochondria Glycogen granules0.5 µmGlycogenGlycogen: an animal polysaccharideCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsStructural Polysaccharides•Cellulose is a major component of the tough wall of plant cells•Like starch, cellulose is a polymer of glucose, but the glycosidic linkages differ•The difference is based on two ring forms for glucose: alpha () and beta ()LE 5-7LE 5-7a Glucosea and b glucose ring structuresb GlucoseStarch: 1–4 linkage of a glucose monomers.Cellulose: 1–4 linkage of b glucose monomers.Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings•Polymers with alpha glucose are helical•Polymers with beta glucose are straight•In straight structures, H atoms on one strand can bond with OH groups on other