Cellular Respiration

1. Cellular Respiration Food In… ATP Out!

2. Feel the Burn • Do you like to run, bike, or swim? These all are good ways to exercise. When you exercise, your body uses oxygen to get energy from glucose,a six-carbon sugar. 1. How does your body feel at the start of exercise, such as a long, slowrun? How do you feel 1 minute into the run; 10 minutes into the run? 2. What do you think is happening in your cells to cause the changesin how you feel? 3. Think about running as fast as you can for 100 meters. Could youkeep up this pace for a much longer distance? Explain your answer.

3. Cellular respiration: the process by which glucose molecules are broken down to release energy. • Occurs in mitochondria of all eukaryotic cells—plant cells and animal cells. What is cellular respiration?

4. Aerobic Respiration: requires oxygen • Produces 36 ATP (from each glucose molecule) • Steps: Glycolysis, Kreb's Cycle and ETC • Anaerobic Respiration: does not require oxygen • Produces only 2 ATP (from each glucose molecule) • Steps: Glycolysis, Fermentation 2Types of Cellular Respiration

5. Steps of aerobic respiration = oxygen present in the cell: 1. Glycolysis: Glucose is broken down producing pyruvate, ATP and NADH. 2. Kreb’s cycle: Produces ATP and NADH & FADH2 3. Electron Transport Chain: Produces 32-34 ATP molecules and water What are the steps of aerobic respiration?

6. Section 9-1 Glucose Krebs cycle Electrontransport Glycolysis Alcohol or lactic acid Fermentation (without oxygen)

8. C6H12O6 + 6O26CO2 + 6H2O + 36 ATP The equation:

9. Aerobic Cellular Respiration Glucose(C6H1206) + Oxygen(02) Glycolysis KrebsCycle ElectronTransportChain ATP CO2 + H2O

10. Glycolysis: 1st stage of cellular respiration • Lysis = splitting • Glyco = glucose • Occurs in cytoplasm of eukaryoticandprokaryotic cells What is glycolysis?

11. What goes in? • Glucose • 2ATP • What comes out? • 2 pyruvate molecules (splitting of 6 carbon glucose) • 4 ATP (net gain of 2 ATP) • 2NADH(goes to electron transportchain) What is glycolysis?

12. Glycolysis

13. Glycolysis Section 9-1 Glucose 2 Pyruvic acid To the electron transport chain

14. This process is so fast that cells can produce thousands of ATP molecules in just a few milliseconds! • Glycolysis does NOT require oxygen (which is good because this process can happen when oxygen is not available: strenuous exercise) What is glycolysis?

15. Pyruvic acid can enter the mitochondria, but cannot enter the Kreb’s cycle • Must be converted to 2 molecules of Acetyl Co-A (a 2 Carbon molecule) • This step produces CO2 What happens before the Kreb’s Cycle?

17. Figure 9.10 Conversion of pyruvate to acetyl CoA, the junction between glycolysis and the Krebs cycle

18. Kreb’s Cycle: 2nd stage of cellular respiration • occurs in mitochondria • What goes in? • Acetyl Co-A • What comes out? • Carbondioxide (from pyruvic acid breakdown) • 2 ATP • Electron carriers NADH and FADH2 (similar to NADPH in photosynthesis) What is the Kreb’s Cycle?

19. The Krebs Cycle is also called the Citric Acid Cycle

20.  The Krebs Cycle Section 9-2 Citric Acid Production Mitochondrion

22. Electron transport Chain: 3rd stage of cellular respiration • Occurs in the mitochondria’s inner membranes (Cristae) • The energy the electrons from NADH and FADH2 release is captured as ATP. • The final electron acceptor is oxygen. Hydrogen atoms carrying the electrons are joined to this Oxygen producing Water. How does the electron transport chain help us produce ATP?

23. What goes in? • NADH and FADH2 molecules • Oxygen • What comes out? • 32-34ATP! • Water (proof: breath on a mirror) ETC

24. E- Transport Chain

25.  Electron Transport Chain Section 9-2 Electron Transport Hydrogen Ion Movement Channel Mitochondrion Intermembrane Space ATP synthase Inner Membrane Matrix ATP Production

26. Aerobic respiration produces 36 ATP molecules! How much ATP?

28. Anaerobic Respiration: • If no oxygen is present, the pyruvate produced from glycolysis must follow a different path…. • Fermentation: • lactic acid and carbon dioxide • ethyl alcohol and carbon dioxide. What happens if there is no oxygen present?

29. Glycolysis is the first step in anaerobic respiration and produces the only 2 ATP molecules made. • Anaerobic respiration never gets inside a mitochondrion. What is the first step in anaerobic respiration?

30. Fermentation • 2 types: 1. Lactic Acid Fermentation: • occurs in animal cells’ cytoplasm including muscle cells • converts pyruvate into lactic acid • causes muscle soreness What happens after glycolysis if no oxygen is present?

31. 2. Alcoholic Fermentation: • occurs in plants and fungi (yeast) cells’ cytoplasm • converts pyruvate to ethyl alcohol and CO2 • causes bread to rise, creates wine and beer What happens after glycolysis if no oxygen is present?

32. Comparison of Fermentation to Cellular Respiration Lactic Acid Alcoholic Cellular respiration glucose glucose glucose glycolysis (pyruvic acid) glycolysis (pyruvic acid) glycolysis (pyruvic acid) carbon dioxide carbon dioxide water lactic acid alcohol 2 ATP 2 ATP 38 ATP Section 3 Check

33. If there are not enough carbohydrates in an organism’s diet to meet its energy needs, other molecules will be broken down to release energy. • One gram of fat contains more than twice the energy of a gram of glucose. Can other fuels besides carbohydrates be used to make ATP?

34. Comparing Photosynthesis and Cellular Respiration Table 9.1 Comparison of Photosynthesis and Cellular Respiration Cellular Respiration Photosynthesis Food synthesized Food broken down Energy of glucose released Energy from sun stored in glucose Carbon dioxide taken in Carbon dioxide given off Oxygen taken in Oxygen given off Produces sugars from PGAL Produces CO2 and H2O Does not require light Requires light Occurs only in presence of chlorophyll Occurs in all living cells Section 9.3 Summary – pages 231-237