1. Carbohydrate Metabolism Turning Sugar into Energy

2. Outline What is Metabolism? Glycolysis TCA Cycle Electron Transport System

3. What is Metabolism? Sum of all chemical reactions in the body

4. What is Metabolism? Sum of all chemical reactions in the body Creates energy (ATP)

5. Why do we need to make ATP? Power muscular contraction Active Transport Homeostasis Synthesis of macromolecules

6. ATP is short-term energy storage ATP consumed < 1 minute from synthesis

7. Types of Metabolic Reactions Anabolic reactions –Building macromolecules in the body

8. Types of Metabolic Reactions Anabolic reactions –Building macromolecules in the body Catabolic reactions –Hydrolysis of foods in GI tract –Chemical breakdown releases energy

9. Types of Metabolic Reactions Anabolic reactions –Building macromolecules in the body Catabolic reactions –Hydrolysis of foods in GI tract –Chemical breakdown releases energy Where does the energy come from?

10. Fuel Up with Slyders!

11. Our Fuel Sources Carbohydrates –Sugars and starches –First choice of metabolic fuel Fats Protein

12. Glucose: Our Primary Fuel C 6 H 12 O 6 All carbohydrates we consume are eventually converted into glucose

13. Catabolism of Glucose C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy Transfer energy from glucose to ATP Most energy lost as heat Glucose

14. Catabolism of Glucose Occurs as a series of steps…. Major Pathways Glycolysis (does not require O 2 ) -glucose split into 2 parts, generating 2 ATP Aerobic Respiration (requires O 2 ) - catabolizes the products of glycolysis and generates more than 30 ATP

15. Where is Glucose Broken Down? TCA

16. Glycolysis (Sugar Splitting) Occurs in presence and absence of O 2 Occurs in cytoplasm Provides energy during strenuous exercise All I need is Glycolysis…And my Jenny.

17. 1.Glucose enters cell by facilitated diffusion Key Steps in Glycolysis

18. 2.Glucose is Phosphorylated by ATP Key Steps in Glycolysis

19. 3. Glucose split into two 3-carbon molecules Key Steps in Glycolysis

20. 4.Coenzyme NAD + collects hydrogen Key Steps in Glycolysis

21. Coenzymes in Metabolism Collect electrons (hydrogen atoms) during catabolism of glucose –Transfer 2H + and 2 e - at a time to coenzymes NAD + and FAD –NAD + (made from niacin) NAD + + 2H  NADH + H + –FAD (made from vitamin B 2 ) FAD + 2H  FADH 2 Temporary carriers of energy

22. 4.Coenzyme NAD + collects hydrogen Key Steps in Glycolysis

23. 5. Create 4 ATP by substrate-level phosphorylation Key Steps in Glycolysis

24. Substrate-level Phosphorylation

25. 6. Create 2 Pyruvate molecules Key Steps in Glycolysis

26. Final Products of Glycolysis 2 molecules of Pyruvate 2 molecules of NADH + H + 4 gross ATP molecules, but only 2 net ATP Quick Energy….but, not very much ATP Glycolysis Animation

27. Some Cells Stop at Glycolysis Red Blood Cells Skeletal Muscle (during exercise)

28. Much Energy Remains in Pyruvate 2 TCA ATP Produced

29. Aerobic vs. Anaerobic Respiration Kreb’s Cycle Electron Transport Chain So What Happens to Pyruvate?

30. Most ATP is Generated in Mitochondria Two principal steps: Matrix Reactions (Krebs Cycle) occurs in matrix of mitochondria Pyruvate is oxidized and electrons are transferred to NAD + and FAD, forming NADH +H and FADH 2 Membrane Reactions (Electron Transport Chain) Occurs within the inner mitochondrial membrane NADH & FADH 2 are oxidized, transferring energy to ATP and regenerating NAD + and FAD

31. Mitochondria: The Cell Powerhouse

32. The Krebs Cycle Also known as…. Tricarboxylic Acid Cycle TCA Cycle Citric Acid Cycle

33. Major Steps of the TCA Cycle 1. CO 2 removed from Pyruvate and several intermediate molecules C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy CO 2 is a metabolic waste product Glucose

34. 2.Hydrogen removed from intermediate molecules Picked up by NAD + and FAD coenzymes Major Steps of the TCA Cycle

35. Summary of Krebs Cycle 2 pyruvate + 6 H 2 O  6 CO 2 2 ADP + 2 P i  2 ATP 8 NAD + + 8 H 2  8 NADH + 8 H + 2 FAD + 2 H 2  2 FADH 2 Carbon from Pyruvate converted to CO 2 and exhaled Energy has been lost (as heat) or stored in 2 ATP, 8 NADH, and 2 FADH 2.

36. Kreb’s Cycle Animation Do not worry about the following: Names of Intermediate carbon molecules What GTP is (it is an ATP precursor) Focus on the following: CO 2 production Action of coenzymes NAD & FAD Creation of ATP Animation

37. To the Inner Mitochondrial Membrane! 22 TCA

38. So what happens to all of the NADH and FADH?

40. Most ATP is Generated in Mitochondria Two principal steps: Matrix Reactions (Krebs Cycle) occurs in matrix of mitochondria Pyruvate is oxidized and electrons are transferred to NAD + and FAD, forming NADH +H and FADH 2 Membrane Reactions (Electron Transport Chain) Occurs within the inner mitochondrial membrane NADH & FADH 2 are oxidized, transferring energy to ATP and regenerating NAD + and FAD

41. Electron Transport System (ETS) Occurs on Inner mitochondrial membrane Requires oxygen

42. ETS Makes Lots of ATP

43. Electron Transport System 1)NADH and FADH 2 release hydrogen atoms

44. Splitting of Hydrogen 2) Electrons passed along electron transport system Protons (H + ) pumped out of mitochondrial matrix Flow of electrons powers active transport of H +

45. ATP Synthase Creates ATP 3) H + diffuse into matrix through ATP Synthase Flow of H + powers anabolism of ATP

46. Electron Transport System Payoff Produce ~34 ATP Efficiency of 40% Rest is body heat

47. Electron Transport System Electron Transport AnimationAnimation

48. Summary of Glucose Catabolism TCA