Cellular Respiration

1. Cellular Respiration Energy and ATP!!!!

2. The Marathon Challenge • What Happens to Your Body During Periods of Prolonged Exercise • http://www.pbs.org/wgbh/nova/body/marathon-challenge.html

3. C6H12O6 + 6O2(reactants) -----> 6CO2 + 6H20 + energy (heat and ATP) (products)

4. Definition • A catacbolic, exergonic, oxygen requiring process that uses energy extracted from macromolecules (glucose) to produce energy (ATP) and water

5. B. Two Forms of Respiration • 1. Aerobic Respiration • A. Occurs when oxygen is present • B. occurs in the mitochondria of cells • C. Releases more energy (ATP molecules) usually 36-38 ATP molecules per cycle

6. 2. Anaerobic Respiration • A. Occurs when oxygen is not present • B. Releases less energy thn aerobic respiration; only 2-4 ATP molecules per cycle • C. Occurs in the cytoplasm of clls • D. Also called fermentation • (1) Lactic Acid Fermentation • (2) Alcoholic Fermentation

7. 3. In what type of organisms does cellular respiration take place? • A. All organisms! Cellular respiration takes place in all living organisms all the time! • B. Heterotrophs – organisms that must consume their own food • C. Autotrophs – organisms that must make their own food

8. Energy • A. Background Information • 1. def - Capacity to move or change matter • 2. Forms of energy are important to life include Chemical, radiant (heat & light), mechanical, and electrical 3. Energy can be transformed from one form to another

9. 4. Chemical energy is the energy contained in the chemical bonds of molecules • Radiant energy travels in waves and is sometimes called electromagnetic energy. An example is visible light • Cell respiration is a process where the chemical energy that is found in the bonds of food molecules is converted into the chemical bonds of ATP. The ATP bonds can then be broken to release energy for the life processes.

10. 7. Photosynthesis converts light energy to chemical energy 8. Energy that is stored is called potential energy

11. B. Laws of Thermodynamics 1. 1st law- Energy cannot be created or destroyed. • Energy can be converted from one form to another. The sum of the energy before the conversion is equal to the sum of the energy after the conversion.

12. 2. 2nd law- Some usable energy is lost during transformations. During changes from one form of energy to another, some usable energy is lost, usually as heat. The amount of usable energy therefore decreases.

13. C. The Energy Molecule - ATP • 1. Adenosine triphosphate (ATP) 2. Energy carrying molecule used by cells to fuel their cellular processes 3. ATP is composed of an adenine base, ribose sugar, & 3 phosphate (PO4) groups

15. 4. The PO4 bonds are high-energy bonds that require energy to be made & release energy when broken

17. What Does ATP Do for You? It supplies YOU withENERGY!

18. How Do We Get Energy From ATP? By breaking the high- energy bonds between the last two phosphates in ATP

19. What is the Process Called? HYDROLYSIS (Adding H2O) H2O

20. How Does That Happen? An Enzyme! ATPase

21. How is ATP Re-Made? The reverse of the previous process occurs. Another Enzyme is used! ATP Synthetase

22. The ADP-ATP Cycle ATP Synthetase ATP-ase

23. 5. ATP is made & used continuously by cells 6. Every minute all of an organism's ATP is recycled 7. Phosphorylation refers to the chemical reactions that make ATP by adding Pi to ADP • 8. ADP (adenosine diphosphate – only 2 phosphates; di = 2) • ADP + Pi + energy «  ATP + H2O

24. 9. Enzymes  (ATP synthetase& ATPase) help break & reform these high energy PO4 bonds in a process called substrate-level phosphorylation 10. When the high-energy phosphate bond is broken, it releases energy, a free phosphate group, & adenosine diphosphate (ADP)

25. 11. When this occurs, ATP is broken down into a free phosphate group, ADP, and energy is released!

27. Energy Carriers During Respiration: • ATP • NADH • FADH2

28. NADH • A second energy carrying molecule in the mitochondria; produces 3ATP

30. FADH2: A third energy carrying molecule in the mitochondria; produces 2 ATP

31. D. Enzymes in Metabolic Pathways 1. Biological catalysts 2. Speeds up chemical reactions 3. Lowers the amount of activation energy needed by weakening existing bonds in substrates

33. 4. Highly specific protein molecules • 5. Have an area called the active site where substrates temporarily join

34. 6. Form an enzyme-substrate complex to stress bonds 7. Enzyme usable • enzyme substrate complex

35. III. Mitochondria: 1. Has outer smooth, outer membrane & folded inner membrane 2. Folds are called cristae 3. Space inside cristae is called the matrix & contains DNA & ribosomes

36. Mitochondria

37. 4. Site of aerobic respiration • Krebs cycle takes place in matrix • Electron Transport Chain takes place in cristae 

38. Cellular Respiration Overview: 1. C6H12O6 + 6O2 -----> 6CO2 + 6H20 + energy (heat and ATP) 2. Controlled release of energy from organic molecules (most often glucose) 3. The carbon atoms of glucose (C6H12O6) are released as CO2 4. Generates ATP (adenosine triphosphate)

40. Anaerobic vs. Aerobic Cellular Respiration

41. 5. The energy in one glucose molecule may be used to produce 36 ATP 6. Aerobic respiration involves a series of 3 reactions --- Glycolysis, Kreb's Cycle, & Electron Transport Chain

42. Glycolysis: 1. Occurs in the cytoplasm • Present during both aerobic and anaerobic cellular respiration • Summary of the steps of Glycolysis:

44. Glycolysis (cont.)

45. . 4. If oxygen is available to the cell, the pyruvate will move into the mitochondria & aerobic respiration will begin.

46. Net Yield from Glycolysis • 4 NADH2 • 2 CO2 • 4 ATP ( 2 used to start reaction)

47. If no oxygen is available to the cell (anaerobic), the pyruvate will be fermented

48. Anaerobic Respiration • A. Overview • 1. Process that occurs when oxygen is not available • 2. Produces less ATP molecules than aerobic respiration • 3. Occurs in the cytoplasm • 4. Starts with glycolysis • A. The breakdown of glucose to pyruvate

49. Lactic Acid Fermentation • 1. Occurs in animals • 2. Produces Lactic Acid and 2 ATP • 3. Build Up of lactic acid causes burning sensation in muscles and cramping.

50. Lactic Acid Fermentation