BIOL 141 Lecture Notes - Lecture 15: Peptidoglycan, Acetyl Group, Lactase
Monday, September 25, 2017
BIOL 141
•We have enzymes that break down sucrose"
•All covalent bonds have the same strength but vary in potential energy (location of
electrons) - determined by the polarity of bonds, which is determined by the
electronegativity of atoms"
•High potential - electron in a further orbital"
•Low potential - electron in a closer orbital (to nucleus)"
•Non polar - higher potential energy (further away from both nuclei)"
•Polar - closer to nucleus, lower potential energy"
•Carbohydrates - primary fuel for most organisms, short term energy storage"
•Photosynthesis - process that stores energy of sunlight in the chemical energy
(electrons) of C-H bonds in carbohydrates"
•Carbohydrates store more energy than CO2 because the electrons in C-H bonds and
C-C bonds are shared more equally and held less tightly than the electrons in the C-
O bonds"
•Variable structures = unique functions"
•Plants store sugar as starch - mixture o branched (amylopectin) and unbranched
(amylose) a-glucose polymer"
•Animals store sugar as glycogen - highly branched a-glucose polymer, primarily
stored in liver and muscles"
•The hydrolysis of a-glycosidic linkages in glycogen is catalyzed by phosphorylase -
most animal cells contain phosphorylase"
•The a-glycosidic linkages in starch are hydrolyzed by amylase - carbohydrate
digestion, present in saliva"
•Glycogen contains lots of water - due to H bonding"
•Removal of 1 oz of glycogen removes 4 oz of water - water weight"
•B-glucose - structural polysaccharides"
•Cellulose is a structural polymer found in plant cell walls - polymer of b-glucose
monomers"
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