AP Biology Chapter 5. Macromolecules

AP Biology Macromolecules  Smaller organic molecules join together to form larger molecules  macromolecules  4 major classes of macromolecules:  carbohydrates  lipids  proteins  nucleic acids

AP Biology Polymers  Long molecules built by linking chain of repeating smaller units  polymers  monomers = repeated small units  covalent bonds

AP Biology How to build a polymer  Condensation reaction  dehydration synthesis  joins monomers by “taking” H 2 O out  1 monomer provides OH  the other monomer provides H  together these form H 2 O  requires energy & enzymes

AP Biology How to break down a polymer  Hydrolysis  use H 2 O to break apart monomers  reverse of condensation reaction  H 2 O is split into H and OH  H & OH group attach where the covalent bond used to be  ex: digestion is hydrolysis

AP Biology Carbohydrates

AP Biology Carbohydrates  Carbohydrates are composed of C, H, O carbo - hydr - ate CH 2 O (CH 2 O) x C 6 H 12 O 6  Function:  energy u energy storage  raw materials u structural materials  Monomer: sugars  ex: sugars & starches

AP Biology Sugars  Most names for sugars end in -ose  Classified by number of carbons  6C = hexose (glucose)  5C = pentose (fructose, ribose)  3C = triose (glyceraldehyde)

AP Biology What functional groups? carbonyl ketone aldehyde hydroxyl

AP Biology Sugar structure  5C & 6C sugars form rings in aqueous solutions  in cells! Carbons are numbered

AP Biology Numbered carbons C CC C C C 1' 2'3' 4' 5' 6' O

AP Biology Simple & complex sugars  Monosaccharides  simple 1 monomer sugars  glucose  Disaccharides  2 monomers  sucrose  Polysaccharides  large polymers  starch

AP Biology Building sugars  Dehydration synthesis | glucose | glucose glycosidic linkage monosaccharidesdisaccharide | maltose

AP Biology Building sugars  Dehydration synthesis | fructose | glucose glycosidic linkage monosaccharidesdisaccharide | sucrose structural isomers

AP Biology Polysaccharides  Polymers of sugars  costs little energy to build  easily reversible = release energy  Function:  energy storage  starch (plants)  glycogen (animals)  building materials = structure  cellulose (plants)  chitin (arthropods & fungi)

AP Biology Branched vs linear polysaccharides

AP Biology Polysaccharide diversity  Molecular structure determines function  isomers of glucose  How does structure influence function…

AP Biology Digesting starch vs. cellulose

AP Biology Cow can digest cellulose well; no need to eat supplemental sugars Gorilla can’t digest cellulose well; must supplement with sugar source, like fruit

AP Biology Cellulose  Most abundant organic compound on Earth

AP Biology Glycemic index  Which food will get into your blood more quickly?  apple  rice cakes  corn flakes  bagel  peanut M&M

AP Biology Glycemic index  Ranking of carbohydrates based on their immediate effect on blood glucose (blood sugar) levels  Carbohydrate foods that breakdown quickly during digestion have the highest glycemic indices. Their blood sugar response is fast & high.

AP Biology Glycemic index  Which food will get into your blood more quickly?  apple36  rice cakes82  corn flakes84  bagel72  peanut M&M33