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Figure 6.14 The induced fit between an enzyme and its substrate

Figure 6.14 The induced fit between an enzyme and its substrate. How does an enzyme reduce the activation energy?. Figure 6.15 The catalytic cycle of an enzyme. Enzyme + Substrate ES Complex Enzyme + Product.

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Figure 6.14 The induced fit between an enzyme and its substrate

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  1. Figure 6.14 The induced fit between an enzyme and its substrate How does an enzyme reduce the activation energy?

  2. Figure 6.15 The catalytic cycle of an enzyme Enzyme + Substrate ES Complex Enzyme + Product

  3. Environmental effects on enzyme activity and the regulation of enzyme activity.

  4. Some Enzymes require Co-enzymes or Cofactors -Bound at active site, help with catalysis -Co-enzymes are organic molecules, often vitamins or dericvitives -Cofactors are metal ions like Mg++, Zn++, Fe++

  5. Inhibition of enzyme activity “Allosteric Inhibition”

  6. Figure 6.18 Allosteric regulation of enzyme activity

  7. Figure 6.19 Feedback inhibition

  8. Figure 6.20 Cooperativity

  9. Figure 6.21 Organelles and structural order in metabolism

  10. What are the metabolic pathways used to harvest energy in cells?

  11. Figure 9.1 Energy flow and chemical recycling in ecosystems

  12. Figure 9.2 A review of how ATP drives cellular work

  13. So what do you think of when you hear the term “Respiration”?

  14. But why do cells need oxygen? C6H12O6 + 6O2 6CO2 + 6H2O + ENERGY (ATP)

  15. Oxidation C6H12O6 + 6O2 6CO2 + 6H2O G = -686 kcal Reduction Oxidation/Reduction Reaction or “Redox Reaction” Oxidation: Loss of electrons (loss of H) Reduction: Gain of electrons (gain of H) Not all Redox reactions involve the complete transfer of electrons, but a change in the degree of sharing of electrons between atoms in covalent bonds. If, in a Redox reaction, electrons end up with less potential energy, then energy is released.

  16. Electrons have less potential energy if they “fall” closer to an electronegative nucleus. Figure 9.3 Methane combustion as an energy-yielding redox reaction Much more stable electron configuration, less potential energy - energy was released.

  17. The coenzyme NAD+ acts as an electron shuttle between dehydrogenation reactions(during the breakdown of glucose) and the transfer of H to O2 to form H2O. Figure 9.4 NAD+ as an electron shuttle Very little energy lost from electrons when transferred to NAD+

  18. oxidation C6H12O6 + 6O2 6CO2 + 6H2O ΔG= -686 kcal reduction ATP Very little energy lost from electrons when transferred to NAD+

  19. Figure 9.6 An overview of cellular respiration (Layer 3)

  20. Figure 9.7 Substrate-level phosphorylation

  21. Figure 9.6 An overview of cellular respiration (Layer 3)

  22. Figure 9.5 An introduction to electron transport chains Oxidative Phosphorylation

  23. Glycolysis

  24. Figure 9.9 A closer look at glycolysis: energy investment phase (Layer 2)

  25. Figure 9.9 A closer look at glycolysis: energy payoff phase (Layer 4)

  26. http://www.northland.cc.mn.us/biology/Biology1111/animations/glycolysis.htmlhttp://www.northland.cc.mn.us/biology/Biology1111/animations/glycolysis.html

  27. Glycolysis Summary

  28. Kreb’s Cycle Summary (In mitochondial matrix) -Carbons of pyruvate CO2 -ATP generated by substrate level phosphorylation -More NADH (and FADH2) formed

  29. Figure 9.10 Conversion of pyruvate to acetyl CoA, the junction between glycolysis and the Krebs cycle Matrix Outer membrane Inner membrane

  30. Figure 9.11 A closer look at the Krebs cycle (Layer 4) http://www.youtube.com/watch?v=FgXnH087JIk

  31. Now, how do we cash-in on the high-energy electrons of NADH and FADH2? How many have we generated from a molecule of glucose? Glycolysis: 2NADH 2Pyruvate 2Acetyl COA: 2NADH Kreb’s Cycle: 6NADH, 2FADH2

  32. Figure 9.5 An introduction to electron transport chains Oxidative Phosphorylation

  33. Figure 9.13 Free-energy change during electron transport Electron Transport Chain

  34. Figure 9.15 Chemiosmosis couples the electron transport chain to ATP synthesis http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter9/animations.html#

  35. Each NADH results in 3 ATP Each FADH2 results in 2 ATP http://www.sp.uconn.edu/%7Eterry/images/movs/synthase.mov

  36. So how much ATP is formed from 1 Glucose? Substrate level phosphorylation? Oxidative phosphorylation?

  37. Figure 9.16 Review: how each molecule of glucose yields many ATP molecules during cellular respiration 28 ATP 30-32 ATP

  38. Figure 9.18 Pyruvate as a key juncture in catabolism

  39. Figure 9.17a Fermentation

  40. Figure 9.17b Fermentation

  41. Figure 9.19 The catabolism of various food molecules

  42. Figure 9.20 The control of cellular respiration  Phosphofructokinase: inhibited by ATP, Citrate. Activated by ADP and AMP.

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