1. Cellular Respiration

3. The Chemistry of Respiration energy and mitochondria clip

4. Adenosine triphosphate ► The energy released during respiration is not used directly by cells. ► Instead it is used to make a molecule called ATP which stores the energy until it is needed. ATP = Adenosine triphosphate

5. What does ATP do? ► ATP supplies energy for all the processes that need it. ► For example: ► movement ► chemical reactions ► growth. slow twitch/fast twitch investigation

6. Structure of ATP adenosine Pi

7. ► ► How is ATP formed?

8. Formation of ATP ATP is made when another molecule called adenosine diphosphate (ADP) is bonded to a third inorganic phosphate (Pi) using the energy released from glucose. ATP is made when another molecule called adenosine diphosphate (ADP) is bonded to a third inorganic phosphate (Pi) using the energy released from glucose.

9. Pi adenosine Pi + adenosine Pi Enzymes Energy from respiration Energy Rich bond formed

10. Summarized as: ADP + Pi ATP The whole process is under the control of enzymes

11. The role of ATP ► ATP stores the energy in the third bond of the molecule ► How is energy released?

12. ► The energy is released when that bond is broken to release the third inorganic phosphate (Pi).

13. Pi adenosine Pi + Energy released to do work ATP ADP Enzymes adenosine Pi

14. Summary ATP ADP + Pi energy (out) energy (in) cellular respiration cell activities ATP energy (out) cellular respiration cell activities The whole process is an enzyme controlled reaction.

15. Aerobic Respiration Aerobic respiration = respiration with oxygen.

16. glucose + OXYGEN energy + carbon dioxide + water (to make ATP)

17. Aerobic respiration happens in 3 stages: Stage 1 – Glycolysis glyco lysis glucose splitting

18. In glycolysis, a glucose molecule is broken down into pyruvic acid. energy released to make small quantity of ATP (2 molecules) series of enzyme controlled reactions 2 pyruvic acid, 4 ATP (used 2), 2 NADH glucose Glycolysis does not require oxygen

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20. Glycolysis Section 3 Cellular Respiration Chapter 5

21. Stage 2 – Breakdown of pyruvic acid The pyruvic acid made in glycolysis (stage1) still contains a lot of energy It can only be broken down to release the rest of the energy in the presence of oxygen. It can only be broken down to release the rest of the energy in the presence of oxygen.

22. energy released to make large quantity of ATP (34 molecules) series of enzyme controlled reactions pyruvic acid carbon dioxide + water

23. Kreb’s cycle AKA Citric Acid cycle ► ► Citric acid is the first compound formed

24.  The Process- ► one C- atom is removed from pyruvic acid ► If the cell has enough ATP- the new molecules are changed to fats for storage ► If the cell needs ATP- the new molecules are used in the Krebs Cycle. ► Krebs Cycle- produces 2 CO2, 1 ATP, NADH, and another carbon molecule that can repeat the cycle

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26. Krebs Cycle Section 3 Cellular Respiration Chapter 5

27. ► Electron Transport Chains- NADH can give electrons to move the electron transport chain.  Proton pumps move protons outside the mitochondrial membranes.  As they cross the membrane again, they provide energy to make ADP into ATP  Extra Hydrogens join oxygen molecules to form water

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29. Electron Transport Chain of Aerobic Respiration Section 3 Cellular Respiration Chapter 5

30. ATP production – summary 34 ADP + 34 Pi = 34 ATP glucose pyruvic acid carbon dioxide + water 2 ADP + 2 Pi = 2 ATP

31. Summary of ATP production ► Stage 1, 2, and 3 release all the chemical energy in one molecule of glucose to make a total of 36 ATP molecules. 2 molecules ATP from glucose  pyruvic acid 2 molecules ATP from glucose  pyruvic acid 34 molecules ATP from pyruvic acid  carbon- dioxide + water 34 molecules ATP from pyruvic acid  carbon- dioxide + water Total 36 molecules ATP

32. Anaerobic Respiration (in animals) anaerobic = in the absence of oxygen

33. In low oxygen conditions or during heavy exercise, when not enough oxygen can be supplied, muscle cells swap to anaerobic respiration

34. glycolysis still happens as it does not require oxygen in absence of oxygen pyruvic acid is turned into lactic acid. pyruvic acid lactic acid glucose 2 ADP + 2 Pi 2 ATP

35. A build up of lactic acid produces muscle fatigue. Muscle fatigue makes muscles ache and contract less powerfully. A recovery period is needed. During this time more oxygen is taken in to convert the lactic acid back into pyruvic acid again. The volume of oxygen needed is called the oxygen debt.

36. Summary oxygen debt e.g. during hard exercise oxygen debt repaid during recovery time glucose pyruvic acid lactic acid

37. Anaerobic Respiration in plants The same process occurs in plants and yeast in low oxygen conditions, e.g. muddy, flooded soils.

38. glycolysis still happens, producing 2 ATP molecules This time in absence of oxygen, pyruvic acid is turned into carbon dioxide and ethanol glucose pyruvic acid ethanol + carbon dioxide This is irreversible 2 ADP + 2 Pi 2 ATP

39. Aerobic respiration Anaerobic Respiration in animals in plants and yeast Oxygen required? Glycolysis occurs ATP yield Glucose completely broke down? End products

40. Comparison of aerobic and anaerobic respiration Aerobic respiration Anaerobic Respiration in animals in plants and yeast Oxygen required? yesnono Glycolysis occurs yesyesyes ATP yield 36ATP2ATP2ATP Glucose completely broke down? yesnono End products Carbon dioxide and water Lactic acid Ethanol and carbon dioxide

41. Food for Thought… ► Humans store excess energy in the form of fat instead of carbohydrates. Why is this?

42. Helpful Hints ► When broken down by the body, each six- carbon fat molecule yields 51 ATP ► A six carbon carbohydrate would yield 36 ATP ► Carbohydrates store water when bound. Water yields zero ATP when metabolized. Fat stores no water.

43. Continued… ► An adult who weighs 70 kg can survive on the energy from fat for 30 days without eating. ► The same person would have to weigh nearly 140 kg to survive 30 days on carbohydrates.

44. ► The End