Unit 3 Genetics

• Aerobic pathway


  Pathway of glucose metabolism that requires oxygen

  
• Anaerobic pathway


  Pathway of glucose metabolism that does not require oxygen

  
• Glucose metabolism


  1. Glycolysis

  2. TCA Cycle

  3. Electron Transport Chain

  4. ATP Synthase
• Glycolysis, TCA Cycle & Oxidative Phosphorylation utilize the energy of glucose to produce ATP, releasing CO2

  
• At every step of glucose metabolism, molecules are reduced or oxidized
• Glycolysis produces 4 ATPs, 2 ATPs are left after the process
• Oxidative phosphorylation produces a large amount of ATP compared to substrate-level phosphorylation
• Glycolysis occurs in the cytoplasm, TCA Cycle and Oxidative Phosphorylation occur in the mitochondria

  
• ATP is produced by substrate-level phosphorylation in glycolysis and TCA Cycle, and by oxidative phosphorylation in the electron transport chain
• CO2 is produced and O2 is consumed during glucose metabolism
• If oxygen concentration drops to zero


  ETC stops, ATP synthase stops, TCA cycle stops, glycolysis may continue through fermentation
• Electron transport chain


  Series of REDOX reactions that establish an electrochemical gradient to power ATP synthase
• The final electron acceptor in the ETC is O2, which is reduced to water
• Fermentation


  Anaerobic pathway that oxidizes NADH to NAD+ to allow glycolysis to continue and produce ATP

  
• Different cells in the human body dynamically adapt their nutrient utilization
• Metabolic inhibitors


  Substances that block specific steps in glucose metabolism
• Inhibitors of the electron transport chain

  • Rotenone (blocks complex I)
  • Carboxin (blocks complex II)
  • Antimycin (blocks complex III)
  • Cyanide (blocks complex IV)
• Inhibitors of oxidative phosphorylation

  • Oligomycin (blocks ATP synthase)
• Uncoupling agents


  Substances that allow protons to diffuse across a membrane, uncoupling electron transport from ATP synthesis
• Uncoupling agents


  • 2,4-Dinitrophenol (DNP)
• Metabolic inhibitors and uncouplers are useful tools to study cellular processes

  
• Cyanide binds to cytochrome c oxidase

  ETC stops, oxygen consumption decreases, glucose consumption increases