BIOL 101 1st Edition Lecture 5 Outline of Last Lecture I Why Carbon II Isomers III Hydrocarbons IV Functional Groups V Chart of 6 Functional Groups VI Introduction to Macromolecules Chapter 5 Outline of Current Lecture Proteins I Structure II Amino Acids III Polypeptide Chains IV Levels of Protein Structures V Protein Function Carbohydrates I Structure II Monosaccharide Current Lecture These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Chapter 5 Proteins Functional Group Quiz Tuesday I II III IV Structure a Polymers of amino acids monomers b Connected by peptide bonds know names of bond c Up to 50 of the dry weight of cells are proteins d Each has unique 3 D shape that determines function e Protein functions i Structural support ii Transport of molecules ex Hemoglobin iii Movement ex contract and expand muscles iv Biological catalysts enzymes Amino Acids a Monomers of protein 20 common ones that makes up proteins b Classified by their R group i Nonpolar ii Polar iii Charged c Know common shape of all amino acids d All have an asymmetric carbon carbon has 4 different groups of atoms bonded to it e Asymmetric carbon causes amino acids to have isometric forms D and L forms i Only use L isomer to make proteins Polypeptide Chain a Many amino acids joined together by peptide bonds b Formed by peptide bonds c Peptide bonds formed by dehydration synthesis d Amino acids connected by peptide bonds have a repeating structure e N C C N C C N C C backbone of the protein f N terminus free amine group one end NH2 g C terminus free carboxyl group other end CO2H Levels of Protein Structure a Primary 1 sequence of amino acids b Secondary 2 structure repeating twisting and folding of the peptide backbone caused by hydrogen bonding in backbone NOT due to R group i 2 types helix 1 pleated sheet 2 c Tertiary 3 structure 3 D shape due to interactions between R groups i Maintained by weak interactions 1 Hydrogen bonds 2 Hydrophobic interactions between nonpolar R groups interior of protein whereas polar R groups are on the surface of protein interacting with H2O ii Some proteins have covalent links that hold the 3 D shape together R group 1 Ex Cysteine 2 disulfide bonds d Quaternary 4 structure association of more than one polypeptide chain not all proteins have this structure some only have one polypeptide chain i Ex collagen 3 helical polypeptide chains intertwined into a triple helix ii Quaternary structure is held together by the same kind of forces as 3 D shape mostly weak forces V Protein Function a Depends on 3 D shape confirmation b Shape of protein allows it to recognize and bind to specific molecules c If it loses the shape it also loses its ability to function d Loss of shape denaturation e Denatured proteins still have the primary structure no broken peptide bonds but it is no longer folded up in the 3 D shape Carbohydrates I Structure a Sugars or polymers of sugar i Monosaccharide simplest monomer ii Disaccharide double sugar b Energy source storage structural molecules source of carbon to make other organic molecules c Bond glycosidic bond d Storage starch glycogen e Structural cellulose II Monosaccharide a Contain C H O in a fixed ratio CH2O b 3 7 carbons sugar molecules i 3C triose ii 5C pentose iii 6C hexose c One hydroxyl with exception of carboxyl carbon C O d Forms ring structures i Ex glucose hexose III IV V Disaccharide a 2 monosaccharides joined by glycosidic bonds i ex maltose two glucoses joined by dehydration synthesis important disaccharide used in brewing beer 1 glycosidic bond joins C 1 of one glucose to C 4 of another lucose ii glucose 6C galactose lactose iii glucose 6C fructose 5C sucrose table sugar Polysaccharide a Macromolecules formed by linking hundreds to thousands of monosaccharides by glycosidic bonds i Storage polysaccharides store energy 1 Ex Starch plants polymer of glucose connected by 1 4 glycosidic bonds 2 glycosidic bonds hydroxyl on C 1 is sticking down from the plane of the ring 3 glycosidic bonds hydroxyl on C 1 is above the plane of the ring 4 Ex Glycogen animals polymer of glucose more branched than starch stored in liver and muscle ii Structural Polysaccharides forms structure 1 Ex Cellulose plants plant cell walls linear and unbranched polymer of glucose connected by 1 4 glucosidic bonds polymer similar to starch but most organisms cannot hydrolyze glucose monomers from cellulose 2 Ex Chitin structure polysaccharide of an amino structure forms exoskeleton of arthropods forms cell walls of some fungi These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute