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Cellular Respiration. Key Concepts: The 3 Stages. Glycolysis anaerobic Citric Acid (Krebs) Cycle aerobic Electron Transport Chain aerobic. What is anaerobic respiration?. Oxygen. What is aerobic respiration?. Oxygen. Why is Aerobic Respiration Needed?.
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Key Concepts: The 3 Stages • Glycolysis • anaerobic • Citric Acid (Krebs) Cycle • aerobic • Electron Transport Chain • aerobic
What is aerobic respiration? Oxygen
Why is Aerobic Respiration Needed? • It produces 15 times more energy than anaerobic respiration • Energy = ATP • When oxygen is present, glucose can be further broken down • 34 or 36 ATP as opposed to 2 ATP from glucose
Citric Acid Cycle • Pyruvate from glycolysis moves from the cytoplasm to the mitochondria • Converted to Acetyl CoA • Removal of a CO2 molecule and transformation of NAD+ to NADH • Citric Acid (6 carbon molecule) is formed from the acetyl group • Forms a 5 carbon molecule after oxidation • Removal of a CO2 molecule and transformation of NAD+ to NADH • Forms a 4 carbon molecule • Transformation of ADP into ATP (ADP + P = ATP) • Converts NAD+ to NADH • Removal of CO2 • Transforms into a different 4 carbon molecule • Transformation of NAD+ to NADH and FAD to FADH2 • Cycle starts over with the other pyruvate molecule
Citric Acid Cycle • Harvests 2 ATP molecules • CO2 is a waste product • NADH and FADH2 are made and will be used in the ETC • http://www.1lecture.com/Biochemistry/How%20the%20Krebs%20Cycle%20Works/index.html
Electron Transport Chain • NADH and FADH2 come into play • Takes place in the membrane of the mitochondria • Network of electron-carrying proteins • NADH molecule transforms into NAD+ • Gives up its electrons • Moves across proteins • Energy created by moving electrons lets H+ ions move to intermembranous space • FADH2 molecule transforms into FAD+ • Gives up electrons • Moves across proteins • Causes H+ to move to intermembranous space • Protons move across membrane, electrons bounce from protein to protein • Electrons meet with protons and oxygen to make H2O (reduction rxn) • High concentration of protons in the intermembranous space • Those protons are channeled into an enzyme able to turn ADP + P into ATP
Electron Transport Chain • Products = H2O and many ATP molecules • Electrons travel through proteins • Meet with hydrogen to create protons capable of moving into the intermembranous space • Later, they meet with those protons to create water • Protons travel through enzyme to make ATP • Concentration
Compare/Contrast Glycolysis Citric Acid Cycle • Aerobic • FADH2 • 2 ATP • NADH • Mitochondria • Anaerobic • Pyruvate • 2 ATP • NADH • Cytoplasm • Each make 2 ATPs • Pyruvate • Make ATP • NADH • Make ATP • Aerobic • In mitochondria • Use NADH • Use FADH2 • Use electrons • Makes many ATP molecules • Intermembranous space of mitochondria • Aerobic respiration ETC