Chapter 7 “Cellular Respiration” Glycolysis & Fermentation Aerobic Respiration AKA OXIDATION OF GLUCOSE

Cellular Respiration Overview A process where organisms break down food to make ATP EVERYONE DOES IT!!! Overall Reaction: C6H12O6+6O2  6CO2+6H2O+Energy (ATP) Anaerobic Path (no O2), 2 Steps: net 2 ATP Not efficient Glycolysis Fermentation: Lactic Acid or Alcoholic Aerobic Path (O2), 3 Steps: net 36 ATP Krebs cycle Electron Transport Chain

Overview, cont. 2 ATP 36 ATP

Glycolysis Location: cytoplasm Products: 2 pyruvate (3-C) 2 NADH (e- acceptors) 4 ATP – 2 ATP used = 2 ATP net NEXT STEP VARIES IF 02 IS PRESENT OR ABSENT

Fermentation: Without O2 Lactic Acid Location: cytoplasm Products: Regenerates NAD+ Uses: Food production: cheese & yogurt Muscle cells (i.e. sprint) Alcoholic Location: cytoplasm Products: Regenerate NAD+ Ethyl Alcohol CO2 Yeast & some plant cells Uses: Wine & beer Bread making

Lactic Acid Fermentation

Alcoholic Fermentation

Quick Review

Aerobic Respiration (O2) Overview 2 Steps: Krebs Cycle (KC) Electron transport chain (ETC) Location: Prokaryotes: KC & ETC in cytosol Eukaryotes: KC: mitochondrial matrix ETC: inner mitochondrial membrane Products: KC: 6NADH, 2FADH2, 2ATP, 4CO2 ETC: 34 ATP

Mitochondrion

Krebs Cycle Start: Pyruvic Acid (PA) enters matrix PA + Acetyl Coenzyme A Acetyl CoA (2-C) & CO2 Yields NADH Transition Step

Stop! Let’s Do Some Accounting Work! Step Molecule How Many Glycolysis NADH ATP Transition CO2 Krebs FADH2 ETC ??????????????????????

Electron Transport Chain NADH & FADH2 release H+ & e- to make ATP e- released energy pump H+ between 2 membranes Chemiosmosis: generates ATP O2 final electron acceptor + e- + H+ Produces H2O Regenerate NAD+ & FAD http://www.sumanasinc.com/webcontent/animations/content/cellularrespiration.html  

“Cash In Values” Each NADH = 3 ATP Each FADH2 = 2 ATP

Energy Yield/ Efficiency Calculations!!