1. Metabolism Transformations and Interactions Copyright 2005 Wadsworth Group, a division of Thomson Learning

2. Metabolism Photosynthesis Fuel Metabolism Copyright 2005 Wadsworth Group, a division of Thomson Learning

3. Chemical Reactions Copyright 2005 Wadsworth Group, a division of Thomson Learning

4. Adenosine Triphosphate Copyright 2005 Wadsworth Group, a division of Thomson Learning

5. Chemical Reactions Coupled reactions Copyright 2005 Wadsworth Group, a division of Thomson Learning

6. A Typical Cell

7. Chemical Reactions Copyright 2005 Wadsworth Group, a division of Thomson Learning

9. Chemical Reactions Helpers in reactions –Enzymes Cofactors –Coenzymes Copyright 2005 Wadsworth Group, a division of Thomson Learning

10. Nutrients for Energy Copyright 2005 Wadsworth Group, a division of Thomson Learning

11. Nutrients for Energy Glycolysis Pyruvate  acetyl CoA TCA cycle Electron transport chain Copyright 2005 Wadsworth Group, a division of Thomson Learning

12. Glycolysis: Glucose-to- Pyruvate

13. Glucose The fate of pyruvate –Anaerobic vs. aerobic pathways Copyright 2005 Wadsworth Group, a division of Thomson Learning

14. Glucose The fate of pyruvate –Anaerobic Pyruvate-to-lactic acid –Cori cycle Copyright 2005 Wadsworth Group, a division of Thomson Learning

15. Pyruvate-to-Lactic Acid (Anaerobic)

16. Glucose The fate of pyruvate –Aerobic Pyruvate-to-acetyl CoA Copyright 2005 Wadsworth Group, a division of Thomson Learning

17. Pyruvate- to-Acetyl CoA (Aerobic)

18. Copyright 2005 Wadsworth Group, a division of Thomson Learning The Paths of Pyruvate and Acetyl CoA

19. Copyright 2005 Wadsworth Group, a division of Thomson Learning Glucose yields energy

20. Glycerol & Fatty Acids Glycerol-to-pyruvate Copyright 2005 Wadsworth Group, a division of Thomson Learning

21. Glycerol & Fatty Acids Fatty acids-to-acetyl CoA Copyright 2005 Wadsworth Group, a division of Thomson Learning

22. Fatty acids-to-acetyl CoA, cont’d This repeating step is also known as beta-oxidation!

23. Fats Enter the Energy Pathway

24. Glycerol & Fatty Acids Fatty acids cannot be used to synthesize glucose: Why is this important??

25. Amino Acids Amino acids-to-acetyl CoA

26. Amino Acids Amino acids-to-glucose

27. Amino Acids Deamination –Keto acid –Ammonia

28. Amino Acids Transamination

29. Amino Acids Ammonia- to-urea Copyright 2005 Wadsworth Group, a division of Thomson Learning

30. Urea excretion via the kidneys

31. Copyright 2005 Wadsworth Group, a division of Thomson Learning

32. The Final Steps The TCA cycle –Acetyl-CoA goes in and oxaloacetate comes out...which ironically is used to continue the cycle...? –Many B vitmins used as cofactors. –By-products go into the E- transport chain. –ATP generated along the way! Copyright 2005 Wadsworth Group, a division of Thomson Learning

33. The TCA Cycle

34. The Final Steps The electron transport chain - Consumes oxygen - Produces carbon dioxide and water - Produces energy as ATP! Copyright 2005 Wadsworth Group, a division of Thomson Learning

35. Electron Transport Chain and ATP Synthesis

36. The Final Steps The kcalories-per-gram secret revealed Copyright 2005 Wadsworth Group, a division of Thomson Learning

37. The Central Pathways of Energy Metabolism

38. Energy Balance Feasting—Excess Energy –Excess protein is converted to fat but this is inefficient and indirect. Its priority is other roles. –Excess carbohydrate –Excess carbohydrate is converted to fat but this is inefficient and indirect. Its priority is glycogen stores. –Excess fat is efficiently converted to fat. The transition from feasting to fasting draws on reserves.

39. Economics of Feasting

40. Economics of Fasting

41. Glucose needed for the brain Protein meets glucose needs Suppression of appetite Slowing of metabolism Are you starving now??

42. Energy Balance Fasting—Inadequate Energy –Symptoms of Starvation Muscle wasting Decreased heart rate, respiratory rate, metabolic rate, and body temperature Impaired vision Organ failure Decreased immunity Depression, anxiety, and food-related dreams... yes, if I was starving I would naturally dream about food!