Macromolecules Smaller organic molecules join together to form

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

Polymers § Long molecules built by linking repeating building blocks in a chain u monomers § building blocks § repeated small units u H 2 O covalent bonds HO H Dehydration synthesis AP Biology HO H

How to build a polymer § Synthesis u You gotta be open to “bonding”! joins monomers by “taking” H 2 O out § one monomer donates OH– § other monomer donates H+ § together these form H 2 O u H 2 O requires energy & enzymes HO H enzyme Dehydration synthesis Condensation reaction AP Biology HO H

How to break down a polymer Breaking up is hard to do! § Digestion u use H 2 O to breakdown polymers § reverse of dehydration synthesis § cleave off one monomer at a time § H 2 O is split into H+ and OH– w H+ & OH– attach to ends requires enzymes HO u releases energy H 2 O u enzyme H Hydrolysis AP Biology Digestion HO H

Carbohydrates AP Biology

CH 2 OH H HO O H OH Carbohydrates energy molecules AP Biology 2006 -2007

Carbohydrates § Carbohydrates are composed of C, H, O carbo - hydr - ate CH 2 O (CH 22 O) O)xx C 66 H 12 O (CH 12 66 § Function: energy u raw materials u energy storage u structural materials u § Monomer: sugars § ex: sugars, starches, cellulose AP Biology sugar sugar

Sugars § Most names for sugars end in -ose § Classified by number of carbons 6 C = hexose (glucose) u 5 C = pentose (ribose) u 3 C = triose (glyceraldehyde) u CH 2 OH H HO O H OH H AP Biology 6 H OH Glucose H CH 2 OH OH C O H HO H 5 OH O HO H Ribose H H C OH 3 OH H Glyceraldehyde

Functional groups determine function carbonyl aldehyde carbonyl ketone AP Biology

Sugar structure 5 C & 6 C sugars form rings in solution Where do you find solutions in biology? In cells! AP Biology Carbons are numbered

Numbered carbons C 6' 5' C O C 4' C 1' energy stored in C-C bonds C 3' AP Biology C 2'

Simple & complex sugars § Monosaccharides simple 1 monomer sugars u glucose u § Disaccharides 2 monomers u sucrose u § Polysaccharides large polymers u starch u AP Biology CH 2 OH H HO O H OH H H OH Glucose H OH

Building sugars § Dehydration synthesis monosaccharides | glucose AP Biology H 2 O | glucose disaccharide | maltose glycosidic linkage

Building sugars § Dehydration synthesis monosaccharides disaccharide H 2 O | sucrose (table sugar) | glucose AP Biology | fructose Let’s go to the videotape!

Polysaccharides § Polymers of sugars costs little energy to build u easily reversible = release energy u § Function: u energy storage § starch (plants) § glycogen (animals) w in liver & muscles u structure § cellulose (plants) § chitin (arthropods & fungi) AP Biology

Linear vs. branched polysaccharides slow release starch (plant) energy storage What does branching do? glycogen (animal) AP Biology fast release Let’s go to the videotape!

Polysaccharide diversity § Molecular structure determines function in starch in cellulose isomers of glucose u structure determines function… u AP Biology

Digesting starch vs. cellulose starch easy to digest enzyme cellulose hard to digest enzyme AP Biology

Cellulose § Most abundant organic compound on Earth herbivores have evolved a mechanism to digest cellulose u most carnivores have not u § that’s why they eat meat to get their energy & nutrients § cellulose = undigestible roughage AP Biology But it tastes like hay! Who can live on this stuff? !

Cow can digest cellulose well; no need to eat other sugars Gorilla can’t digest cellulose well; must add another sugar source, like fruit to diet Regents Biology

Helpful bacteria § How can herbivores digest cellulose so well? u BACTERIA live in their digestive systems & help digest cellulose-rich (grass) meals Caprophage Ruminants Regents Biology Tell Ime about eat the rabbits, WHAT! again, George!