……….in the mitochondria AEROBIC RESPIRATION ……….in the mitochondria

Mitochondria The mitochondria are organelles (found in eukaryotic cells) which specialize in the production of large quantities of ATP Processes cannot proceed without oxygen (aerobic) Three stages: Pyruvate Oxidation Kreb’s Cycle Electron Transport Chain

Mitochondria Possess a double membrane composed of a smooth outer membrane and a highly folded inner membrane The folds of the inner membrane are called cristae, which have numerous substances (proteins, enzymes, etc.) embedded in its phospholipid bilayer

Mitochondria The inner membrane also creates two compartments which play a critical role in aerobic respiration The Mitochondrial Matrix: a protein rich liquid that fills the innermost space of the mitochondria The Intermembrane Space: a fluid filled space that lies between the inner and outer membrane

Pyruvate Oxidation The two pyruvate molecules formed in glycolysis are transported into the mitochondria (via a transport protein) where a multi-enzyme complex catalyzes the following three changes: Low energy carboxyl group is removed from pyruvate as CO2 (the enzyme responsible is called pyruvate decarboxylase) The remaining 2-carbon portion is oxidized by NAD+, therefore NAD+ gets reduced to NADH. The 2 carbon molecule becomes (acetate) acetic acid. A sulfur containing compound called coenzyme A is attached to the acetate forming acetyl CoA

Stage Two: Pyruvate Oxidation decarboxylation 2. dehydrogenation 3. reaction with coenzyme A to produce acetyl-CoA

Overall Equation 2 pyruvate + 2NAD+ + 2CoA  2 acetyl CoA + 2NADH + 2CO2 enter the Kreb’s Cycle proceed to Stage 4 (ETC & Chemiosmosis) to produce ATP by oxidative phosphorylation diffuse out of mitochondrion and out of cell as waste

Homework Section 4.1 p. 169-170 Section 4.2 p. 174-175 Know this stuff!! 