1. Biochemistry Bioenergetics: How the body converts food to energy

2. Bioenergetics  Metabolism  Metabolism: The sum of all Chemical Reactions involved in maintaining the dynamic state of the cell –Catabolism –Catabolism - breaking down of molecules to supply energy –Anabolism –Anabolism - synthesis of molecules –Biochemical Pathway –Biochemical Pathway - a series of consecutive chemical reactions

3. Common Catabolic Pathway Conversion of FOOD to ATP:  FOOD produces C 4 and C 2 fragments  C 4 and C 2 fragments enter Citric Acid Cycle  CO 2, NADH, FADH 2, are produced  Electron Transport  Electron Transport produces ATP

4. O2O2 O2O2 Citric Acid Cycle C2C2C2C2 C2C2C2C2 C2C2C2C2 CO 2 C4C4C4C4 C4C4C4C4 NADH FADH 2 ATP H2OH2O outer membrane inner membrane e - transport

5. Cells and Mitochondria Components of a typical cell:  nucleus - replication of cell begins here  lysosomes - remove damaged cellular components  Golgi bodies - package and transport proteins  organelles - specialized structures with specific function  mitochondria - common catabolic pathway

6. Cells and Mitochondria

8. Mitochondria  Mitochondria –Two membranes –Common Catabolic Pathway Crista –Enzymes located in folds or “Crista” Protein Gates –Transport thru the inner membrane occurs with the help of Protein Gates

9. Mitochondrion

10. Common Catabolic Pathway 2 Parts:  Citric Acid Cycle –or Tricarboxylic Acid Cycle –or TCA cycle –or Kreb’s Cycle  Oxidative Phosphorylation –or Electron Transport –or Respiratory Chain 1 2

11. Compounds - ADP  Adenosine diphosphate (ADP)

12. Compounds - ATP  AMP, ADP, ATP High energy phosphate anhydride bonds triphosphate

13. Compounds - ATP  ATP –We make about 88 lbs. of ATP a day!!! –Used for: »muscle contraction »nerve signal conduction »biosynthesis

14. Fig. 26.6, p.651

15. Compounds - Redox  NAD + and FAD –Oxidizing agents –Actually coenzymes –Contain an ADP core (part of R or R’) NAD + FAD

16. Compounds - Redox  NAD + is converted to NADH Oxidized form Reduced form to ET

17. Compounds - Redox  FAD is converted to FADH 2 Oxidized form Reduced form to ET

18. Compounds Acetyl  The Acetyl carrying group - Acetyl coenzyme A  Carrying handle is Pantothenic Acid and Mercaptoethylamine

19. Coenzyme A

20. 4C3C2C

21. Fig. 26.8, p.652

22. http://www.youtube.com/watch?v=iXmw3fR8fh0 http://www.youtube.com/watch?v=lvoZ21P4JK8 http://www.youtube.com/watch?v=A1DjTM1qnPM http://www.youtube.com/watch?v=FgXnH087JIk

23. Citric Acid Cycle  Acetyl CoA contains a 2 carbon fragment that is carried into the Citric Acid Cycle  Also called the: –Tricarboxylic Acid Cycle –TCA Cycle –Kreb’s Cycle  Acetyl group is split out as CO 2 C5C5 CO 2 C4C4 C4C4 C6C6 C2C2

24. Citric Acid Cycle  Step 1 –oxaloacetate will show up in last step –acetyl CoA is the THIO ESTER of acetic acid (CoA is Co Enzyme A)

25. Citric Acid Cycle  Step 1B –citrate or citric acid produced –citrate has 6 C (How many acid groups?)

26. Fig. 26.8, p.652

27. Citric Acid Cycle  Step 2 –dehydration to cis-Aconitate –hydration to isocitrate –enzymes required for each Rx

28. Fig. 26.8, p.652

29. Citric Acid Cycle  Step 3 –oxidation and decarboxylation –CO 2 is from the ???

30. Fig. 26.8, p.652

31. Citric Acid Cycle  Step 4 –Where did the CO 2 come from???

32. Fig. 26.8, p.652

33. Citric Acid Cycle  Step 5 –GTP is Guanosine triphosphate (as good as ATP!)

34. Fig. 26.8, p.652

35. Citric Acid Cycle  Step 6 –Oxidation with FAD –Fumaric Acid is trans-Fumaric Acid –Barbiturate is an inhibitor of Succinate dehydrogenase

36. Fig. 26.8, p.652

37. Citric Acid Cycle  Step 7 –hydration reaction –fumarase is enzyme

38. Citric Acid Cycle  Step 8 –oxidation using NAD + –product is oxaloacetate!

39. Fig. 26.8, p.652

40. Electron (and H + ) Transport  End products of the Citric Acid Cycle Reduced (or spent) Coenzymes –NADH –FADH 2  Carry H+ and e- and yield energy when combining with oxygen: 4 H + + 4 e - + O 2 2 H 2 O

41. Electron (and H + ) Transport  Many Enzymes are involved in ET  Enzymes are imbedded in inner membrane of the mitochondria  Enzymes are in a particular sequence –each accepts electrons –increasing affinity for electrons  Final acceptor of electrons is molecular O 2 to make water O2O2

42. Fig. 26.10, p.656

43. http://www.youtube.com/watch?v=xbJ0nbzt5Kw http://www.youtube.com/watch?v=Idy2XAlZIVA http://www.youtube.com/watch?v=A32CvcfA_K0&feature=PlayList& p=F09BC040A0B953F8&playnext=1&playnext_from=PL&index=10 http://www.youtube.com/watch?v=1engJR_XWVU Electron Transport chain - youtube

44. Electron (and H + ) Transport  Many Enzymes are involved in Oxidative Phosphorylation 2 H + + 2 e - + 1/2 O 2 H 2 O Flavo- protein Lipid bilayer FeS protein Q enzyme b b c1c1 c a a3a3 ATPase cytochromes O2O2O2O2 NADHNAD + FADH 2 FAD ATP 2 H + 2 ATP overall 2 ATP produced 3 ATP overall 3 ATP produced O 2-

45. The Energy Yield from a C 2  Each NADH produces 3 ATP  Each FADH 2 produces 2 ATP (Each pair of H + produces 1 ATP )  For each C 2 unit (acetyl CoA) we produce... –1 GTP directly (same as 1 ATP) from step 5 TCA –3 NADH in ET (3 x 3 = 9 ATP) Indirect –1 FADH 2 in ET (1 x 2 = 2 ATP) Indirect For a total of..................... 12 ATP (and some waste CO 2 ) $ Indirect (from ET)

46. Conversion of ATP How does the body utilize this Chemical Energy?  Conversion to Other Forms –biosynthesis  Electrical Energy –ion gradients (K +, Na + )  Mechanical Energy –muscle contraction  Heat Energy –maintain 37 o C or 98.6 o F

47. Muscle Contraction Chemical Energy converted to Mechanical Energy:  Thick (myosin) and thin (actin) filaments  Hydrolysis of ATP causes the interaction of the filaments (muscle contraction) contraction