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Metabolic Pathways

Metabolic Pathways. Metabolic Pathways. This section will cover the cellular pathways that produce ATP from glucose and other nutrients. (Chapter 7). There is potential energy in covalent bonds. But where does the energy come from?. Metabolic Pathways. H. H. H. H. Metabolic Pathways.

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Metabolic Pathways

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  1. Metabolic Pathways

  2. Metabolic Pathways This section will cover the cellular pathways that produce ATP from glucose and other nutrients. (Chapter 7)

  3. There is potential energy in covalent bonds. But where does the energy come from? Metabolic Pathways

  4. H H H H

  5. Metabolic Pathways The disorder of the system has decreased. or The entropy has decreased. ΔS < 0

  6. Metabolic Pathways Since ΔG = - TΔS Then If ΔS<0, ΔG>0

  7. H H H H ΔG>0 or the potential energy has increased

  8. There is potential energy in covalent bonds. But where does the energy come from? Metabolic Pathways

  9. H H Metabolic Pathways The energy is stored in the electrons.

  10. H H Metabolic Pathways A covalent bond is the sharing of 2 electrons.

  11. H H Metabolic Pathways The electrons have a certain degree of entropy. Because the orbitals overlap in a covalent bond, there is less entropy.

  12. H H Metabolic Pathways ΔS<0 then ΔG>0 or the potential energy has increased.

  13. Bond Energy C-N 308 kJ/mol C-C 348 C-O 360 H-O 366 C-H 413 H-H 436

  14. H H Metabolic Pathways Strong bonds have low chemical energy and weak bonds have high chemical energy.

  15. REDOX reactions oxidation - reduction reactions Metabolic Pathways

  16. In a REDOX reaction electrons are transferred from one atom to another. This transfer of electrons is a transfer of energy. Metabolic Pathways

  17. Transferring electrons from one molecule to another is a means by which energy can be transferred from one molecule to another. Metabolic Pathways

  18. In the cell, glucose is metabolized to carbon dioxide, water, and energy. C6H12O6 + 6 O2→ 6 CO2 + 6 H2O + energy The energy yielding steps in the metabolism of glucose are REDOX reactions. Metabolic Pathways

  19. REDOX reactions are chemical reactions in which one of the reactants becomes oxidized (loses an electron) and the other reactant becomes reduced (gains an electron). Metabolic Pathways

  20. Oxidation-Reduction reactions or Redox reactions are 2 reactions that always occur together. Metabolic Pathways

  21. Oxidation is LOSS of electrons. Metabolic Pathways

  22. This loss of electrons can be outright to form an ion or the electrons may be shared with a substance that has a greater affinity for the electrons, such as oxygen. Metabolic Pathways

  23. Most oxidation reactions are associated with the liberation of energy. Metabolic Pathways

  24. Reduction is the GAIN of electrons. Metabolic Pathways

  25. All reductions are accompanied by an oxidation. Metabolic Pathways

  26. A is oxidized B is reduced Metabolic Pathways

  27. An oxidizing agent is the reactant that accepts an electron or a hydrogen atom. A reducing agent is the reactant that donates an electron or a hydrogen atom. Metabolic Pathways

  28. Metabolic Pathways Reducing Agent Oxidizing Agent

  29. A is oxidized B is reduced Metabolic Pathways

  30. During the metabolism of glucose, glucose donates electrons. Therefore, glucose is oxidized. Metabolic Pathways C6H12O6 + 6 O2 6 CO2 + 6 H2O + energy

  31. Oxygen accepts electrons. Therefore, oxygen is reduced. Metabolic Pathways C6H12O6 + 6 O2 6 CO2 + 6 H2O + energy

  32. Metabolic Pathways

  33. The Hydrogen molecule H2 H H H Metabolic Pathways The Hydrogen atom H+ Hydrogen ion (proton)

  34. Whenever one molecule reduced, another is oxidized. In this process, energy is transferred as the electron is transferred from molecule to molecule. This energy will ultimately be captured in ATP. ADP + Pi ATP Metabolic Pathways

  35. However, during glucose oxidation, the electrons of glucose are first passed to an electron carrier. Metabolic Pathways C6H12O6 + 6 O2 6 CO2 + 6 H2O + energy

  36. The cell has 2 electron carriers NAD+ or FAD. Metabolic Pathways

  37. NAD+ and FAD accept the electrons from glucose and transfers them to the mitochondria, where ATP is synthesized. Metabolic Pathways

  38. The coenzyme nicotinamide adenine dinucleotide (NAD) is an essential electron carrier in cellular redox reactions. Metabolic Pathways

  39. NAD+

  40. O O P O- O- NADP+ NADP+ is usually used for anabolic reactions.

  41. NAD can be oxidized or reduced. NAD exists in an oxidized form NAD+ and a reduced form NADH + H+. Metabolic Pathways

  42. NAD+ accepts 2 electrons + 1 hydrogen ion (H+) from 2 hydrogen atoms. Metabolic Pathways

  43. NADH + H+NAD+ + energy Metabolic Pathways

  44. The reduction of NAD+ requires an input of energy (endergonic): NAD+ + 2H + energy→ NADH + H+ Metabolic Pathways

  45. The oxidation of NADH+ H+ is exergonic: NADH + H+→ NAD+ + energy Metabolic Pathways

  46. Energy is required. Energy is required.

  47. Energy is released.

  48. Energy is released. Energy is required.

  49. Flavin adenine dinucleotide (FAD) is another electron transporter in cellular redox reactions FAD + 2H FADH2 Metabolic Pathways

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