CHAPTER 5 NOTES I MACROMOLECULES most macromolecules are complex polymers built by linking simple monomers A Carbohydrates organic polymer include both sugars and polymers of sugars the simplest carbohydrates are monosaccharides or simple sugars these are the monomers from which more complex carbohydrates are constructed Disaccharides are double sugars consisting of two monosaccharides joined by a covalent bond They also consist of macromolecules called polysaccharides polymers composed of many sugar building blocks B Proteins organic polymer C Nucleic acids organic polymer D Lipids II SYNTHESIZING AND BREAKING POLYMERS Monomers are analogous to train cars Cars have same external features but carry different cargo A Condensation Dehydration reactions join monomers into polymers Removing water to combine monomers one monomer provides a hydroxyl group OH while the other provides H B Hydrolysis reactions break polymers into monomers Add water to break up polymers water bursting polymers disassembled to monomers C Monomer type and order dictate polymer behavior Gycosidic linkage covalent bond formed between two monosaccharides by a dehydration reaction How many different ways can the cars be arranged 1 different polymers possible 2 The behavior of each polymer will be unique due to a different monomer b of monomer III CARBOHYDRATES sacharride sugar Carbs serves as short term fuel storage and building material plants mainly Includes both simple sugars monomers and their polymers Carbon hydrates Cn H2O n Short term easily accessed energy stores Various structural roles Often classified by either of carbons in molecule triose pentose hexose or the of monomers in the polymer 3 carbons triose sugars 5 carbons pentose sugars 6 carbons hexose sugars A Monosaccharide building blocks 1 glucose a primary energy source of all cells b product of photosynthesis 2 galactose 3 fructose B Disaccharides two monomers joined together 1 Dehydration synthesis using saccharides forms a glycosidic bond Covalent bond 2 disaccharides glycosidic linkage 2 Common disaccharides a glucose glucose maltose b glucose galactose lactose c glucose fructose sucrose C Polysaccharides There are 2 main classes both composed of saccharide monomers 1 Storage polysaccharides 1 4 linkage can be broken by humans can be utilized for energy a Types i plants starch ii animals glycogen Carbohydrate polymers with alpha bonds are helical coils conserve space 2 Structural polysaccharides 1 4 linkage is chemically very stable and cannot be broken by human enzymes a Types i cellulose cell walls ii lichitin insect exoskeletons When a glucose forms a ring the hydroxyl group attached to the number 1 carbon is positioned either below or above the plane of the ring These two ring forms are called alpha and beta respectively In starch all the glucose monomers are in the alpha configuration Carbohydrate polymers with beta bonds lay flat good for cell walls We lack the enzymes to break beta bonds termites possess them this is the reason they can eat wood Carbohydrates are mostly glucose IV PROTEINS blue collar workers do SPECIFIC things enzymes catalysts structural building blocks for cell machinery A Amino acid monomers are linked to form protein polymers 1 Monomer structure basic amino acid structure changes in body because of pH a 20 different amino acids aa s exist b the radical R group differs amongst aa s c R groups are hydrophobic or hydrophilic hydrophobic orients towards protein interior to get away from water hydrophilic orients towards protein exterior because it doesn t mind water Uncharged polar Charged polar ionic d the pH determines the charge status of the NH2 and COOH group 2 Dehydration synthesis using amino acids form peptide bonds Be able to identify peptide bonds amino end carboxyl end caboose Peptide bonds are formed by dehydration reactions which link the carboxyl groups of one amino acid to the amino group of the next B Polypeptides fold into specific 3D conformations which determine function The degree of folding is termed the level of protein structure 4 levels The 4 levels reflect the amount and type of intra molecular and inter molecular bonding and are all necessary for protein function 1 Primary 1 linear unique sequence of amino acids in a peptide bond Unique monomer sequence encoded by the genes Recall that monomer order and chemical nature affect polymer behavior Changing the amino acid order and replacing it changes a cell a lot sickle cell for example one cell wants of be on the inside and one wants to be on the outside changes shape 2 Secondary 2 1st level of folding a Alpha helix H bond forms between electronegative atoms from the carbonyl and NH2 groups every 4th amino acid This produces a spiral helix shape The folding and coiling of the poly peptide into a repeating configuration includes the alpha helix and beta pleated sheet b Beta pleated sheet H bonds form between antiparallel sections of the polypeptide chain make up the core of many proteins Tertiary 3 2nd level of folding The overall 3D shape of the protein polypeptide R group interaction is mostly responsible a Weak to medium strength R group interactions H bonding between polar R groups Ionic bonding between acidic basic R groups Hydrophobic Van der Waal interactions between nonpolar R groups Results from interactions between amino acids and R groups Proteins don t have function until it folds into shape until its tertiary level Deep inside ionic bonds dorm in proteins only place they can exist 3 b Very strong R group interactions disulfide bridges covalent bonds between 2 cysteine monomers reinforce the shape of a protein Rigid and strong 4 holds the shape Quaternary 4 3rd level of folding rate Involves inter molecular bonding between multiple polypeptide chains The aggregation of multiple tertiary polypeptide subunits ex hemoglobin collagen C Denaturation unravels a protein s 3D shape Loss of 3D shape means loss of function Loss of function is a continuum not on off Denaturation when a protein unravels and loses its native conformation 1 temperature heating denatures cooling renatures if no peptide bonds are broken and the protein is not too complex when you heat a molecule it goes straight to the bonds electron bonds absorb energy faster and faster 2 salt high salt concentrations disrupts electrostatic attractions messes with interactions charges when you add salt 3 pH increasing or decreasing pH affects NH2 and COOH charge status charges on