Aerobic Respiration Pyruvate Oxidation The Citric Acid Cycle (Kreb’s Cycle)

Get Organized NameWhereStartEndCost Glycolysis CytoplasmGlucose2 Pyruvate +4 ATP -2 ATP +2 NADH Pyruvate oxidation Mitochondrial matrix 2 pyruvate + 2 CoA 2 CO acetyl- CoA + 2 NADH Citric Acid Cycle (Krebs cycle) Mitochondrial matrix 2 acetyl-CoA + 2 oxaloacetate 2 CoA + 2 oxaloacetate + 4 CO 2 +2 ATP +6 NADH, +2 FADH 2 Electron Transport Chain (Oxidative phosphorylation) Mitochondrial membrane NADH FADH 2 NAD+ FAD +34 ATP TotalCellC 6 H 12 O 6 (s) + 6 O 2 (g) 6 CO 2 (g) + 6 H 2 O(l) + heat ΔG = −2880 kJ per mol of C 6 H 12 O ATP molecules

What happens to pyruvate?

Pyruvate Oxidation If oxygen is present, the pyruvate molecules are transported from the cytoplasm into the mitochondrial matrix

Pyruvate Oxidation

Oxidative decarboxylation of pyruvate 3 enzyme-catalyzed changes: decarboxylation oxidation attachment of coenzyme A

Pyruvate Oxidation pyruvate  acetyl-CoA CO 2 released NADH produced

The Citric Acid Cycle (Krebs Cycle) 8 enzyme-catalyzed reactions in the mitochondrial matrix aerobic cyclic: oxaloacetate is the reactant of the first reaction and product of the last reaction Purpose: generate more high energy molecules (NADH, FADH 2 and ATP)

Reactions… decarboxylation (reactions 3 & 4) redox (reactions 3,4,6,8) energy production (reaction 5)

Citric Acid Cycle Summary 2 cycles for EACH glucose molecule acetyl-CoA  oxaloacetate (per cycle) 2 CO 2 released (per cycle) 3 NADH produced (per cycle) 1 FADH 2 produced (per cycle) 1 ATP produced (per cycle)

oxaloacetate is regenerated by now, all 6 carbons from glucose have been oxidized to CO 2 all of the energy from glucose is in the form of ATP, NADH and FADH 2 ( fuel for the electron transport chain, for making lots of ATP) Citric Acid Cycle Summary Continued

Krebs Cycle Overall Reaction 2 acetyl CoA + 6NAD FAD + 2ADP + 2 P i 4 CO NADH + 6 H FADH ATP

Animations Simple reaction review: nts/Biology/Bio231/krebs.html nts/Biology/Bio231/krebs.html Animation & Quiz: hill.com/sites/ /student_view 0/chapter25/animation__how_the_krebs _cycle_works__quiz_1_.html hill.com/sites/ /student_view 0/chapter25/animation__how_the_krebs _cycle_works__quiz_1_.html (

Preview of ETC… If you’re confused about the Electron Transport Chain, this animation might help: hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535: :535::/sites/dl/free/ /120071/bio11.swf::Electron%20Transport%20System%20a nd%20ATP%20Synthesishttp://highered.mcgraw- hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535: :535::/sites/dl/free/ /120071/bio11.swf::Electron%20Transport%20System%20a nd%20ATP%20Synthesis (

ER: What do you do? Patient is admitted unconscious. Mentioned that she had general weakness, giddiness, headaches, vertigo, confusion, and perceived difficulty in breathing.vertigo Breathing is now rapid and patient is entering a deep coma, with cherry red skin colour. You suspect cardiac arrest is coming. What do you ask?

Patient worked in at a gold mining site and there was a release of hydrogen cyanide. Cyanide an inhibitor of enzyme cytochrome c oxidase in the electron transport chain. It attaches to the iron within this protein. The binding of cyanide to this enzyme prevents transport of electrons from cytochrome c to oxygen (can’t use electron transport chain)….. What is happening to the patient?

What do you do? Atropine: Treats bradycardia (a heart rate < 60 beats per minute). Hydroxocobalamin: (vitamin B12a) binds with the cyanide to form the harmless cyanocobalamin Epinephrine: Treat cardiac arrest, return of spontaneous circulation Defibrillator: Reset the heart beat to a normal rhythm

Homework Read pg (ETC & Chemiosmosis) Q pg 182 # 4,8,9,10