Electron Transport Chain

  1. What leaves the citric acid cycle to enter and serve as fuel for the the electron transport chain?
    • 6 NADH
    • 2 FADH2
  2. Why is the electron transport chain called a chain
    It involves a series of molecules, mostly proteins, which are sequentially linked to each other.
  3. Where are the molecules of the electron transport chain embedded?
    partition-like mitochondrial structures called cristae
  4. What does electron transport involve?
    a series of redox reactions?
  5. Is oxygen required for electron transport? Is it consumed?
    • Yes it is required and consumed
    • Highly aerobic
  6. How many molecules of oxygen are consumed for each glucose molecule?
  7. What starts the electron cascade?
    NADH is oxidized to NAD+ with the release of energy which starts the electron cascade
  8. Describe the electron cascade in the electron transport chain.
    Electrons slide down an "energy hill" as electron carrier molecules undergo sequential redox reactions
  9. Describe the carrier molecules in the electron transport chain.
    The first carrier molecule is oxidized as the next one is reduced, and so on, down to the last atom which is oxygen. Small amounts of energy are shed and temporally stored within the mitochondria during each carrier molecule transfer.
  10. What is the last atom in the electron transport chain?
  11. Why do electrons move downhill in the electron transport chain?
    because each carrier molecule has a greater affinity for electrons than it's uphill neighbor
  12. What eventually occurs within the electron transfer chain in relation to the conversion of ADP to ATP?
    small amounts of energy are shed and temporarily stored within the mitochondria during each carrier molecule transfer

    eventually enough energy is accumulated to reduce ADP to ATP
  13. What does the final oxygen atom in the chain capture and what does it form at the bottom of the hill?
    captures the cascading hydrogen electron at the bottom of the hill to form H2O
  14. What is another fuel for the electron transport chain other than NADH?
  15. Why is FADH2 less significant than NADH?
    It enters the electron transport chain at a lower energy level and produces 1/3 less energy than NADH
  16. What would occur if oxygen atoms where directly combined with hydrogen atoms without the intervening electron transport cascade?
    a violent explosion
  17. In the electron transport chain what substance are produced? How much of each?
    • 32 (34) molecules of ATP
    • 6 molecules of water
  18. How much energy of the glucose molecule is captured by ATP?
  19. What becomes of the unused energy in the electron transport chain?
    • The remaining energy (60%) is given off as heat
    • used to maintain body temperature higher than ambient temperature
Card Set
Electron Transport Chain
Chapter 25 A&PII Electron Transport Chain