AP Biology Carbohydrates

AP Biology OH H H HO CH 2 OH H H H OH O Carbohydrates energy molecules

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, cellulose sugar C 6 H 12 O 6 (CH 2 O) x

AP Biology Photosynthetic Organisms  Photosynthetic bacteria  Cyanobacteria  Protists  Spirogyra  Plants  All are photosynthetic

AP Biology Monosaccharides  Most names for sugars end in -ose  Classified by number of carbons  6C = hexose (glucose)  5C = pentose (ribose)  3C = triose (glyceraldehyde) OH H H HO CH 2 OH H H H OH O Glucose H OH HO O H H H Ribose CH 2 OH Glyceraldehyde H H H H OH O C C C 653

AP Biology Functional groups determine function carbonyl ketone aldehyde carbonyl

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

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

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

AP Biology C 6 H 12 O 6  Fructose  fruit sugar converted from glucose – sweetener in honey  Galactose  Dairy sugar, component of lactose, necessary for mammals that are mothers

AP Biology Polysaccharide diversity  Molecular structure determines function  isomers of glucose  structure determines function… in starchin cellulose

AP Biology Glucose  α – glucose  β – glucose  Cannot bond w/ eachother b/c OH + H does not leave anything behind  Alpha w/ Alpha  Beta/ Beta  We can’t break down cellulose b.c we don’t have the enzyme

AP Biology Alpha Beta

AP Biology Building sugars  Dehydration synthesis Dehydration synthesis glycosidic linkage | glucose | glucose monosaccharidesdisaccharide | maltose H2OH2O

AP Biology Building sugars  Dehydration synthesis | fructose | glucose monosaccharides | sucrose (table sugar) disaccharide H2OH2O

AP Biology Dissaccharide C 12 H 22 O 11  Maltose –  α-glucose + α- glucose  α-1,4 glycosidic linkage  Found in plant seeds – energy source  Sucrose  α-glucose + fructose  Lactose  α-glucose + galactose  Milk sugar  Lactose intolerant – lacking lactase  α-1,4 glycosidic linkage

AP Biology Polysaccharides  Polymers of sugars  costs little energy to build  easily reversible = release energy  Function: (do not copy below - wait til next slide  energy storage  starch (plants)  glycogen (animals)  in liver & muscles  structure  cellulose (plants)  chitin (arthropods & fungi)

AP Biology energy storage 1.Starch  Amylose (30% of starch) α-1,4 glycosidic linkage  Amylopectin (70%) α-1,4 and every 30ish glucose units 1,6 glycosidic linkage  Store in amyloplasts

AP Biology 2. Glycogen (Animal starch)  Humans/animals store in muscle cells and liver  Chains of branching α-glucose (lots of branches)

AP Biology Linear vs. branched polysaccharides starch (plant) glycogen (animal) energy storage What does branching do? slow release fast release

AP Biology structure  3. Cellulose  Primary component of cell walls  Cotton and Paper are purely cellulose  Chain of β glucose - β -1,4 glycosidic linkage  Humans do not have enzymes to break down cellulose

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

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

Regents Biology 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?  BACTERIA live in their digestive systems & help digest cellulose-rich (grass) meals Ruminants Tell me about the rabbits, again, George! I eat WHAT! Caprophage

AP Biology  4. Chitin  Exoskeletons of arthropods/ fungal cell walls  β -1,4 glycosidic linkage w/ amine chains

Regents Biology Let’s build some Carbohydrates! EAT X