Chapter 3 Biological MoleculesAside from water, most biologically related molecules contain carbon.Carbon atoms are the most versatile building blocks of moleculesAnother factor which leads to the versatility of organic molecules is the attachment of functional groups (see table 3-1)Functional GroupsSlide 6Functional groups:SYNTHESIZING ORGANIC MOLECULES: A MODULAR APPROACH---Polymers are chains of similar building blocks or monomers. ---A Monomer is a subunit (or building block) of a polymer.Slide 10---Dehydration synthesis is a reaction in which the covalent linkage of the monomers is accompanied by the “removal” of a water molecule.---Hydrolysis is the breaking of the covalent bond between two monomers by the addition of water.Slide 13Carbohydrates are used as fuels and building material-Carbohydrates are classified by the number of simple sugars. -Monomers are simple sugars called monosaccharides.-Major source of nutrients for cells. -Glucose is the most common -Can be produced by photosynthetic organisms from CO2, H2O, and light.Monosaccharides can be joined to form disaccharides and polysaccharidesSlide 18Slide 19Polysaccharides ---Polysaccharides are macromolecules that are polymers of a few hundred or thousand monosaccharides.Storage polysaccharide -Stored sugars can be hydrolyzed as needed.Slide 22Carb-loadingWater WeightStructural polysaccharides---Cellulose (see fig 3-9) is a linear unbranched polymer of glucoseSlide 27Hydrogen bonds hold the cellulose strands together---Chitin(see fig 3-10) is a structural polysaccharide that is a polymer of an amino sugar.Slide 30Lipids are mostly nonpolar hydrophobic molecules composed mainly of carbon and hydrogen-Important lipids are grouped into 3 types:Which is NOT a type of lipid?Oils, Fats and Waxes---Fats and oils are macromolecules constructed from fatty acids and glycerol.Slide 36Slide 37Slide 38Slide 39Function of fats and oils:Why do we crave fats?OlestraSlide 43FatsSlide 45Saturated vs. Unsaturated FatsSaturated versus Unsaturated FatsCookies!!!!Slide 49Slide 50Phospholipids-Phospholipid molecules cluster in water with hydrophobic tails turned in.Slide 53SteroidsSlide 55Proteins are the molecular tools for most cellular functions.-Range in length from a few monomers to more than a thousand. -Each protein has a unique linear sequence of amino acids -Proteins are abundant, making up 50% (or more) of some cells dry weight.Slide 58Slide 59Four levels of protein structure (see fig 3-20)Slide 61Primary structureSecondary structureSlide 64Tertiary structureSlide 66Slide 67Slide 68Quaternary structureSlide 70Why would changing the shape of a protein change its function?Nucleic Acids: Information storage and transmission.---Nucleic acids are polymers of nucleotides linked together by dehydration synthesis reactions.---Nucleotides are composed of a sugar, a phosphate group, and a base.The sugar is a 5-carbon ring conformation.In RNA the sugar is ribose, whereas in DNA the sugar is a derivative of ribose called, deoxyribose.The sugar and phosphate groups form a linkage which makes up the nucleic acid backbone.Variation in DNA and RNA comes from the order of the nucleotides (i.e., DNA sequence)Slide 79If you were going on a long trip and could take along only 10 pounds of food, it would be best to select food from which group?Chapter 3Biological MoleculesAside from water, most biologically related molecules contain carbon.---Organic molecules are molecules containing carbon.Carbon atoms are the most versatile building blocks of moleculesCarbon has a valence of 4.Can bind to 2, 3, or 4 other atoms.Another factor which leads to the versatility of organic molecules is the attachment of functional groups (see table 3-1)---Functional groups are small characteristic groups of atoms which are frequently bonded to the carbon skeleton of organic molecules.Functional GroupsSimilar to the carbon skeleton of an organic moleculeSimilar to the functional groups attached to the carbon skeleton of an organic moleculeTable 3-1Functional groups:•Have specific chemical and physical properties.•Are regions of organic molecules which are frequently chemically reactive.•Behave consistently from one organic molecule to another.•Can determine the chemical properties of the organic molecule in which they are located.SYNTHESIZING ORGANIC MOLECULES: A MODULAR APPROACH Biological molecules are often put together in subunits, or modules, called monomers.---the simple molecules combined to form more complex ones---monomers into polymers---Polymers are chains of similar building blocks or monomers.---A Monomer is a subunit (or building block) of a polymer.>>>>>The reaction that forms a polymer from monomers is dehydration synthesisFig 3-1---Dehydration synthesis is a reaction in which the covalent linkage of the monomers is accompanied by the “removal” of a water molecule.---Hydrolysis is the breaking of the covalent bond between two monomers by the addition of water.Fig 3-2Polymer type Monomer type ExampleCARBOHYDRATES SUGARSMonosaccharides GlucoseDisaccharides SucrosePolysaccharides StarchGlycogenCelluloseLIPIDS FATTY ACIDSTriglycerides Oils, fatWax Plant cuticlePhospholipids Cell MembranesSteroids CholesterolPROTEINS AMINO ACIDS Keratin, silkNUCLEIC ACIDS NUCLEOTIDES DNA, RNACarbohydrates are used as fuels and building material---Carbohydrates are organic molecules made of sugars and their polymers.-Carbohydrates are classified by the number of simple sugars.-Monomers are simple sugars called monosaccharides.---Monosaccharides are simple sugars in which carbon, hydrogen, and oxygen occur in the ratio of 1-2-1 for C, H, and O.-Major source of nutrients for cells. -Glucose is the most common-Can be produced by photosynthetic organisms from CO2, H2O, and light.Monosaccharides can be joined to form disaccharides and polysaccharides---Disaccharides are molecules which consist of two monosaccharides joined by a glycosidic linkage. (See fig 3-7)-Glycosidic linkage is a covalent bond formed by a dehydration synthesis between two sugar monomers.Fig. 3-7DISACCHARIDE MONOMERS COMMON USEMaltose Glucose + GlucoseImportant in beer brewingLactose Glucose + GalactoseSugar present in milkSucrose Glucose + FructoseTable sugar, most common disaccharidePolysaccharides---Polysaccharides are macromolecules that are polymers of a few hundred or thousand monosaccharides.-Formed by enzyme-mediated condensation reactions.-Biological functionsEnergy storage(starch
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