BY4 Respiration

Card Set Information

BY4 Respiration
2014-02-25 14:44:21

Wjec BY4
Show Answers:

  1. What is the advantage of having cristae on mitochondria?
    Greater surface area for oxidative phosphorylation.
  2. What is the purpose of phosphorylating Glucose to Fructose 1,6 - Bisphosphate in the first stage of Glycolysis?
    • Make it more reactive.
    • Maintains the concentration gradient for glucose to move in via facilitated diffusion.
  3. What happens to the Fructose 1,6 Bisphosphate in glycolysis?
    It splits into 2 molecules of triose phosphate.
  4. What happens to the Triose phosphate in Glycolysis?
    • Converted into pyruvic acid.
    • Yeilds 4 ATP from substrate level phosphorylation (net gain is only 2 due to 2 being used to phosphorylate glucose)
    • 2 reduced NAD from dehydrogenation  ( 6 ATP )
  5. How is pyruvate converted into Acetyl coenzyme A?
    • Decarboxylated COremoved 
    • Dehydrogenated hydrogen lost is accepted by NAD to form reduced NAD.
    • The 2 carbon acetate combines with co-enzyme A.
  6. Acetate (2C) combines with Oxaloacetate (4C) to form what in the Krebs cycle?
    • Citrate 
    • 6C
  7. What are the products after Citrate has been decarboxylated and dehydrogenated?
    • CO2
    • reduced NAD
    • Alpha Ketoglutarate (5C)
  8. What are the products of converting Alpha Ketoglutarate to Oxaloacetate?
    • reduced NAD 
    • reduced FAD
    • 1 ATP

    happens twice per glucose molecule.
  9. Why can NAD release 3 ATP ?
    NAD releases 3 ATP as it can associate with 3 proton pumps.
  10. Why can FAD only release 2 ATP?
    FAD releases 2 ATP as it can only associate with 2 proton pumps.
  11. Why does a high concentration of protons build up in the inter membrane space?
    • Proton pumps pump protons from the matrix ( from the reduced NAD and FAD) into the inter membrane space.
    • Powered by the electron transport chain.
  12. How is ATP synthesized by ATP synthetase?
    • Protons flow down ATP synthetase via facilitated diffusion.
    • Which acts as a driving force to combine ADP with Pi to form ATP
  13. What is the role of oxygen in respiration?
    It acts as the final electron acceptor and also combines with protons to form water.
  14. What would happen if there was no oxygen present for the electron transport chain?
    • There would be a build up of protons in the matrix so no concentration gradient across the membrane. 
    • Electrons accumulate along the chain and the reaction comes to a halt.
    • Meaning ATP synthetase cannot function.