Cellular respiration is a catabolic process that occurs in the mitochondria of plants and animals. It uses oxygen to break down glucose and other food molecules to extract energy in the form of ATP. The process involves four main stages: glycolysis, the Krebs cycle, and the electron transport chain and oxidative phosphorylation. This releases energy to produce up to 38 ATP per glucose molecule.

1. Cellular Respiration copyright cmassengale

2. Cellular Respiration A catabolic, exergonic, oxygen (O 2 ) requiring process that uses energy extracted from macromolecules (glucose) to produce energy (ATP) and water (H 2 O). C 6 H 12 O 6 + 6O 2  6CO2 + 6H 2 O + energy copyright cmassengale glucose ATP

3. Question: In what kinds organisms does cellular respiration take place? copyright cmassengale

4. Plants and Animals Plants - Autotrophs : self-producers. Animals - Heterotrophs : consumers. copyright cmassengale

5. Mitochondria Organelle where cellular respiration takes place. copyright cmassengale Inner membrane Outer membrane Inner membrane space Matrix Cristae

6. Redox Reaction Transfer of one or more electrons from one reactant to another . Two types: 1. Oxidation 2. Reduction copyright cmassengale

7. Oxidation Reaction The loss of electrons from a substance . Or the gain of oxygen . C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy copyright cmassengale glucose ATP Oxidation

8. Reduction Reaction The gain of electrons to a substance . Or the loss of oxygen . copyright cmassengale glucose ATP C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy Reduction

9. Breakdown of Cellular Respiration Four main parts (reactions). 1. Glycolysis (splitting of sugar) a. cytosol, just outside of mitochondria. 2. Grooming Phase a. migration from cytosol to matrix. copyright cmassengale

10. Breakdown of Cellular Respiration 3. Krebs Cycle (Citric Acid Cycle) a. mitochondrial matrix 4. Electron Transport Chain (ETC) and Oxidative Phosphorylation a. Also called Chemiosmosis b. inner mitochondrial membrane. copyright cmassengale

11. 1. Glycolysis Occurs in the cytosol just outside of mitochondria. Two phases (10 steps): A. Energy investment phase a. Preparatory phase (first 5 steps) . B. Energy yielding phase a. Energy payoff phase (second 5 steps) . copyright cmassengale

12. 1. Glycolysis A. Energy Investment Phase: copyright cmassengale Glucose (6C) Glyceraldehyde phosphate (2 - 3C) (G3P or GAP) 2 ATP - used 0 ATP - produced 0 NADH - produced 2ATP 2ADP + P C-C-C-C-C-C C-C-C C-C-C

13. 1. Glycolysis B. Energy Yielding Phase copyright cmassengale Glyceraldehyde phosphate (2 - 3C) (G3P or GAP) Pyruvate (2 - 3C) (PYR) 0 ATP - used 4 ATP - produced 2 NADH - produced 4ATP 4ADP + P C-C-C C-C-C C-C-C C-C-C GAP GAP (PYR) (PYR)

14. 1. Glycolysis Total Net Yield 2 - 3C-Pyruvate (PYR) 2 - ATP (Substrate-level Phosphorylation) 2 - NADH copyright cmassengale

15. Substrate-Level Phosphorylation ATP is formed when an enzyme transfers a phosphate group from a substrate to ADP . Example: PEP to PYR copyright cmassengale Enzyme Substrate O - C=O C-O- CH 2 P P P Adenosine ADP (PEP) P P P ATP O - C=O C=O CH 2 Product (Pyruvate) Adenosine

16. Fermentation Occurs in cytosol when “NO Oxygen” is present (called anaerobic). Remember: glycolysis is part of fermentation . Two Types: 1. Alcohol Fermentation 2. Lactic Acid Fermentation copyright cmassengale

17. Alcohol Fermentation Plants and Fungi  beer and wine copyright cmassengale glucose Glycolysis C C C C C C C C C 2 Pyruvic acid 2ATP 2ADP + 2 2NADH P 2 NAD + C C 2 Ethanol 2CO 2 released 2NADH 2 NAD +

18. Alcohol Fermentation End Products: Alcohol fermentation 2 - ATP ( substrate-level phosphorylation) 2 - CO 2 2 - Ethanol’s copyright cmassengale

19. Lactic Acid Fermentation Animals (pain in muscle after a workout). copyright cmassengale 2 Lactic acid 2NADH 2 NAD + C C C Glucose Glycolysis C C C 2 Pyruvic acid 2ATP 2ADP + 2 2NADH P 2 NAD + C C C C C C

20. Lactic Acid Fermentation End Products: Lactic acid fermentation 2 - ATP ( substrate-level phosphorylation) 2 - Lactic Acids copyright cmassengale

21. 2. Grooming Phase Occurs when Oxygen is present (aerobic). 2 Pyruvate (3C) molecules are transported through the mitochondria membrane to the matrix and is converted to 2 Acetyl CoA (2C) molecules. copyright cmassengale Cytosol C C C 2 Pyruvate 2 CO 2 2 Acetyl CoA C-C 2NADH 2 NAD + Matrix

22. 2. Grooming Phase End Products: grooming phase 2 - NADH 2 - CO 2 2- Acetyl CoA (2C) copyright cmassengale

23. 3. Krebs Cycle (Citric Acid Cycle) Location: mitochondrial matrix . Acetyl CoA (2C) bonds to Oxalacetic acid (4C - OAA) to make Citrate (6C) . It takes 2 turns of the krebs cycle to oxidize 1 glucose molecule. copyright cmassengale Mitochondrial Matrix

24. 3. Krebs Cycle (Citric Acid Cycle) copyright cmassengale Krebs Cycle 1 Acetyl CoA (2C) 3 NAD + 3 NADH FAD FADH 2 ATP ADP + P (one turn) OAA (4C) Citrate (6C) 2 CO 2

25. 3. Krebs Cycle (Citric Acid Cycle) copyright cmassengale Krebs Cycle 2 Acetyl CoA (2C) 6 NAD + 6 NADH 2 FAD 2 FADH 2 2 ATP 2 ADP + P (two turns) OAA (4C) Citrate (6C) 4 CO 2

26. 3. Krebs Cycle (Citric Acid Cycle) Total net yield ( 2 turns of krebs cycle) 1. 2 - ATP (substrate-level phosphorylation) 2. 6 - NADH 3. 2 - FADH 2 4. 4 - CO 2 copyright cmassengale

27. 4. Electron Transport Chain (ETC) and Oxidative Phosphorylation ( Chemiosmosis ) Location: inner mitochondrial membrane. Uses ETC (cytochrome proteins) and ATP Synthase (enzyme) to make ATP . ETC pumps H + (protons) across innermembrane ( lowers pH in innermembrane space ). copyright cmassengale Inner Mitochondrial Membrane

28. 4. Electron Transport Chain (ETC) and Oxidative Phosphorylation ( Chemiosmosis ) The H+ then move via diffusion (Proton Motive Force) through ATP Synthase to make ATP . All NADH and FADH 2 converted to ATP during this stage of cellular respiration . Each NADH converts to 3 ATP . Each FADH 2 converts to 2 ATP (enters the ETC at a lower level than NADH ). copyright cmassengale

29. 4. Electron Transport Chain (ETC) and Oxidative Phosphorylation ( Chemiosmosis ) copyright cmassengale Inner membrane Outer membrane Inner membrane space Matrix Cristae

30. 4. ETC and Oxidative Phosphorylation ( Chemiosmosis for NADH ) copyright cmassengale NADH + H + ATP Synthase 1H + 2H + 3H + higher H + concentration H + ADP + ATP lower H + concentration H + (Proton Pumping) P E T C NAD+ 2H + + 1/2 O 2 H 2 O Intermembrane Space Matrix Inner Mitochondrial Membrane

31. 4. ETC and Oxidative Phosphorylation (Chemiosmosis for FADH 2 ) copyright cmassengale FADH 2 + H + ATP Synthase 1H + 2H + higher H + concentration H + ADP + ATP lower H + concentration H + (Proton Pumping) P E T C FAD+ 2H + + 1/2 O 2 H 2 O Intermembrane Space Matrix Inner Mitochondrial Membrane

32. TOTAL ATP YIELD 1. 04 ATP - substrate-level phosphorylation 2. 34 ATP - ETC & oxidative phosphorylation 38 ATP - TOTAL YIELD copyright cmassengale ATP

33. Eukaryotes (Have Membranes) Total ATP Yield 02 ATP - glycolysis (substrate-level phosphorylation) 04 ATP - converted from 2 NADH - glycolysis 06 ATP - converted from 2 NADH - grooming phase 02 ATP - Krebs cycle (substrate-level phosphorylation) 18 ATP - converted from 6 NADH - Krebs cycle 04 ATP - converted from 2 FADH 2 - Krebs cycle 36 ATP - TOTAL copyright cmassengale

34. Maximum ATP Yield for Cellular Respiration (Eukaryotes) 36 ATP (maximum per glucose) copyright cmassengale Glucose Glycolysis 2ATP 4ATP 6ATP 18ATP 4ATP 2ATP 2 ATP (substrate-level phosphorylation) 2NADH 2NADH 6NADH Krebs Cycle 2FADH 2 2 ATP (substrate-level phosphorylation) 2 Pyruvate 2 Acetyl CoA ETC and Oxidative Phosphorylation Cytosol Mitochondria

35. Prokaryotes (Lack Membranes) Total ATP Yield 02 ATP - glycolysis (substrate-level phosphorylation) 06 ATP - converted from 2 NADH - glycolysis 06 ATP - converted from 2 NADH - grooming phase 02 ATP - Krebs cycle (substrate-level phosphorylation) 18 ATP - converted from 6 NADH - Krebs cycle 04 ATP - converted from 2 FADH 2 - Krebs cycle 38 ATP - TOTAL copyright cmassengale

36. Question: In addition to glucose, what other various food molecules are use in Cellular Respiration? copyright cmassengale

37. Catabolism of Various Food Molecules Other organic molecules used for fuel. 1. Carbohydrates: polysaccharides 2. Fats: glycerol’s and fatty acids 3. Proteins: amino acids copyright cmassengale

38. copyright cmassengale