Carbon: The Backbone of LifeSlide 2Slide 3Slide 4The Molecules of LifeMacromolecules are polymers, built from monomersThe Synthesis and Breakdown of PolymersSlide 8Carbohydrates serve as fuel and building materialSlide 10Slide 11PolysaccharidesStorage PolysaccharidesSlide 14Structural PolysaccharidesSlide 16Slide 17Slide 18Slide 19Lipids are a diverse group of hydrophobic molecules1. FatsSlide 22Slide 23Slide 24Slide 25Slide 262. PhospholipidsSlide 28Slide 293. SteroidsSlide 31Proteins have many structures, resulting in a wide range of functionsSlide 33Polypeptides- a polymer of amino acidsSlide 35Slide 36Protein Structure and FunctionSlide 38Four Levels of Protein StructureSlide 40Slide 41Slide 42Sickle-Cell Disease: A Change in Primary StructureSlide 44What else Determines Protein Structure?Nucleic acids store and transmit hereditary informationSlide 47The Structure of Nucleic AcidsSlide 49Nucleotide MonomersNucleotide PolymersThe DNA Double HelixSlide 53Slide 54Carbon: The Backbone of Life•Although cells are 70–95% water, the rest consists mostly of carbon-based compounds•Carbon is unparalleled in its ability to form large, complex, and diverse molecules•Proteins, DNA, carbohydrates, and other molecules that distinguish living matter are all composed of carbon compounds•Organic chemistry is the study of compounds that contain carbon and such organic compounds range from simple molecules to colossal ones•Most organic compounds contain hydrogen atoms in addition to carbon atomsCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings•Carbon atoms can partner with atoms other than hydrogen; for example:–Carbon dioxide: CO2–Urea: CO(NH2)2Carbon chains vary in length and shape•Hydrocarbons are organic molecules consisting of only carbon and hydrogen•Many organic molecules, such as fats, have hydrocarbon components•Hydrocarbons can undergo reactions that release a large amount of energyCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsFig. 4-5Ethane Propane1-Butene 2-Butene(c) Double bonds(d) RingsCyclohexane BenzeneButane2-Methylpropane(commonly called isobutane)(b) Branching(a) LengthFig. 4-6(a) Mammalian adipose cells (b) A fat moleculeFat droplets (stained red)100 µmThe Molecules of Life•All living things are made up of four classes of large biological molecules: carbohydrates, lipids, proteins, and nucleic acids•Within cells, small organic molecules are joined together to form larger molecules•Macromolecules are large molecules composed of thousands of covalently connected atoms•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 speciesCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsMacromolecules are polymers, built from monomers•A polymer is a long molecule consisting of many similar building blocks •These small building-block molecules are called monomers•An immense variety of polymers can be built from a small set of monomers•Three of the four classes of life’s organic molecules are polymers:–Carbohydrates–Proteins–Nucleic acidsCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings•A condensation reaction or more specifically a dehydration reaction occurs when two monomers bond together through the loss of a water molecule•Enzymes are macromolecules that speed up the dehydration process•Polymers are disassembled to monomers by hydrolysis, a reaction that is essentially the reverse of the dehydration reactionThe Synthesis and Breakdown of PolymersCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsFig. 5-2Short polymerHO1 2 3 HHOHUnlinked monomerDehydration removes a watermolecule, forming a new bondHOH2OH1234Longer polymer(a) Dehydration reaction in the synthesis of a polymerHO1234HH2OHydrolysis adds a watermolecule, breaking a bondHOHHHO123(b) Hydrolysis of a polymerCarbohydrates serve as fuel and building material•Carbohydrates include sugars and the polymers of sugars•The simplest carbohydrates are monosaccharide's, or single sugars•Carbohydrate macromolecules are polysaccharides, polymers composed of many sugar building blocks 1. Monosaccharide's•Monosaccharide's have molecular formulas that are usually multiples of CH2O•Glucose (C6H12O6) is the most common monosaccharideCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings•Monosaccharide's serve as a major fuel for cells and as raw material for building molecules•A disaccharide is formed when a dehydration reaction joins two monosaccharides •This covalent bond is called a glycosidic linkageCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsFig. 5-3DihydroxyacetoneRibuloseKetosesAldosesFructoseGlyceraldehydeRiboseGlucoseGalactoseHexoses (C6H12O6)Pentoses (C5H10O5)Trioses (C3H6O3)Monosaccharide'sPolysaccharides•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 linkages•Two major kinds of polysaccharide’s1. Storage Polysaccharides2. Structural PolysaccharidesCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsStorage Polysaccharides•Starch, a storage polysaccharide of plants, consists entirely of glucose monomers•Plants store surplus starch as granules within chloroplasts and other plastids •Glycogen is a storage polysaccharide in animals•Humans and other vertebrates store glycogen mainly in liver and muscle cellsCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsFig. 5-6(b) Glycogen: an animal polysaccharideStarchGlycogenAmyloseChloroplast(a) Starch: a plant polysaccharideAmylopectinMitochondriaGlycogen granules0.5 µm1 µmStructural Polysaccharides•The polysaccharide 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 ()•Chitin, another structural polysaccharide, is found in the exoskeleton of arthropods•Chitin also provides structural support for the cell walls of many fungi Copyright © 2008 Pearson Education, Inc., publishing as