The Krebs Cycle & Electron Transport Chapter 9.2

Krebs Cycle (aka Citric Acid Cycle) Aerobic part of cellular respiration, it requires oxygen The process of breaking pyruvic acid into carbon dioxide (CO2) using oxygen (O2) This process releases energy

Takes place in mitochondrion Pyruvic acid (3C) from glycolysis is broken down to CO2 (leaves 2C) & electrons are removed to change NAD+ to NADH Acetyl-CoA (2C) + 4 C = citric acid (6C)

Citric acid (6 C) is broken down to 5C and then to 4C (CO2 & NADH formed each time) 1 ATP & 1 FADH2 are also formed 4 NADH formed

Electron Transport Chain ETC uses the high energy electrons from the Krebs Cycle to convert ADP into ATP ETC composed of carrier proteins in the inner membrane of the mitochondrion

At the end of ETC is an enzyme that combines e- from the ETC with H & O to form water Oxygen serves as final e- acceptor of the ETC

2 e- moving down the ETC transports H+ across the membrane; charge differential is created and used to form ATP

Most of the ATP produced during cellular respiration is made during the Electron Transport Chain

Totals Glycolysis = 2 ATP Krebs cycle = 2 ATP electron transport = 32 ATP Total 36 ATP

Video: http://www. copernicusproject. ucr. edu/ssi/HSBiologyResources Video: http://www.copernicusproject.ucr.edu/ssi/HSBiologyResources.htm Glycolysis and Cellular Respiration