Cellular Respiration Chapter 7 Cellular Respiration Glycolysis Fermentation

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

Cellular Respiration Overview n n n A process where organisms break down food to make ATP EVERYONE DOES IT!!! Overall Reaction: n C 6 H 12 O 6+6 O 2 6 CO 2+6 H 2 O+Energy (ATP) Anaerobic Path (no O 2), 2 Steps: net 2 ATP n Not efficient 1. Glycolysis 2. Fermentation: Lactic Acid or Alcoholic Aerobic Path (O 2), 3 Steps: net 36 ATP 1. Glycolysis 2. Krebs cycle 3. Electron Transport Chain

Overview, cont. 2 ATP 36 ATP

Glycolysis n n Location: cytoplasm Products: 1. 2. 3. 2 pyruvate (3 -C) 2 NADH (eacceptors) 4 ATP – 2 ATP used = 2 ATP net NEXT STEP VARIES IF 02 IS PRESENT OR ABSENT

Fermentation: Without O 2 Lactic Acid n Location: cytoplasm n Products: 1. Regenerates NAD+ 2. Lactic Acid n Uses: 1. Food production: cheese & yogurt 2. Muscle cells (i. e. sprint) Alcoholic n Location: cytoplasm n Products: 1. Regenerate NAD+ 2. Ethyl Alcohol 3. CO 2 n Yeast & some plant cells n Uses: 1. Wine & beer 2. Bread making

Lactic Acid Fermentation

Alcoholic Fermentation

Quick Review

Aerobic Respiration (O 2) Overview n 2 Steps: 1. 2. n Location: n n n Krebs Cycle (KC) Electron transport chain (ETC) Prokaryotes: KC & ETC in cytosol Eukaryotes: n KC: mitochondrial matrix n ETC: inner mitochondrial membrane Products: n n KC: 6 NADH, 2 FADH 2, 2 ATP, 4 CO 2 ETC: 34 ATP

Mitochondrion

Krebs Cycle n n Start: Pyruvic Acid (PA) enters matrix PA + Acetyl Coenzyme A Acetyl Co. A (2 -C) & CO 2 n Yields NADH Transition Step

Stop! Let’s Do Some Accounting Work! Step Molecule Glycolysis NADH How Many ATP Transition NADH CO 2 Krebs NADH FADH 2 ATP CO 2 ETC ATP ? ? ? ? ? ?

Electron Transport Chain n n NADH & FADH 2 release H+ & e- to make ATP e- released energy pump H+ between 2 membranes n Chemiosmosis: generates ATP O 2 final electron acceptor + e- + H+ Produces H 2 O Regenerate NAD+ & FAD http: //www. sumanasinc. com/webcontent/animations/content/cellularrespirat ion. html n

“Cash In Values” n Each NADH = 3 ATP n Each FADH 2 = 2 ATP

Energy Yield/ Efficiency Calculations!!