1. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Cellular Respiration process where cells break down sugars to produce ATP both autotrophs and heterotrophs use make CO 2 and water from sugar and O 2 Occurs in the mitochondria Products of cellular respiration are the reactants of photosynthesis Products of photosynthesis are the reactants in cellular respiration Two stages 1.Glycolysis 2.Aerobic respiration

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Photosynthesis-Cellular Respiration Cycle

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Cellular Respiration

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Glycolysis takes place in the cytosol of cells (cytoplasm) does not need Oxygen present (anaerobic) Step 1 1 six-carbon glucose molecule is split to form 2 three-carbon pyruvic acid molecules 2 ATP molecules are used

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Glycolysis takes place in the cytosol of cells (cytoplasm) does not need Oxygen present (anaerobic) Step 2 Electrons from the pyruvic acid molecules join NAD + to form NADH Pyruvic acid molecules become Pyruvate 4 ATP are made A net yield of 2 ATP molecules is produced

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Glycolysis

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Glycolysis

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Efficiency of Glycolysis not very efficient at transferring energy from glucose to ATP only about 2% of the energy available from the oxidation of glucose is captured as ATP energy originally contained in glucose is still held in pyruvic acid

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Aerobic Respiration occurs in the mitochondria only occurs if oxygen is present in the cell Two stages 1.Krebs Cycle occurs in the mitochondrial matrix 2.Electron Transport Chain (which is associated with chemiosmosis) located in the inner membrane

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Krebs Cycle Step 1 Pyruvate splits into a two carbon molecule and CO 2 Electrons join NAD+ to make NADH

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Krebs Cycle Step 2 Pyruvic acid (2 carbon molecule) reacts with coenzyme A to form acetyl CoA Acetyl CoA enters the Krebs cycle

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Krebs Cycle Step 3 CoA joins with a four carbon molecule to make Citric acid (a six carbon molecule) Coenzyme A goes back to step 2

13. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Krebs Cycle Step 4 Citric acid is broken down and makes a five carbon molecule NADH is made CO 2 is made

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Krebs Cycle Step 5 The five carbon molecule is broken down to make a four carbon molecule NADH is made CO2 is made 1 ATP is made

15. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Krebs Cycle Step 6 Enzymes rearrange the four carbon molecule Electrons are released NADH is made Products from one glucose molecule: –6 CO 2, 2 ATP, 8 NADH, 2 FADH 2

16. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Krebs Cycle

17. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Electron Transport Chain & Chemiosmosis Step 1 Electrons are removed from NADH and FADH 2

18. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Electron Transport Chain & Chemiosmosis Step 2 Electrons are passed from molecule to molecule in the ETC Hydrogen ions are pumped across the membrane

19. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Electron Transport Chain & Chemiosmosis Step 3 Hydrogen ions diffuse through a protein channel ATP synthase adds phosphates to ADP to Make ATP

20. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Electron Transport Chain & Chemiosmosis Step 4 Oxygen combines with electrons and Hydrogen ions to form water

21. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Efficiency of Cellular Respiration produce up to 38 ATP molecules from a single molecule of glucose 2 from glycolysis, 2 from Krebs, 34 from ETC Cellular respiration is 20 times more efficient than glycolysis alone

22. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Summary of Cellular Respiration

23. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Comparing Aerobic and Anaerobic Respiration

24. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Cellular Respiration Versus Fermentation