Lecture 17: Oxidative Phosphorylation Flashcards Preview

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Flashcards in Lecture 17: Oxidative Phosphorylation Deck (11)
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1
Q

• Know the flow of electrons during respiration

A
Electrons follow a downhill route:
Glucose
-
NADH
-
ETC
-
Oxygen
2
Q

• Describe the role of the electron transport chain in controlling the release of
energy during oxidative phosphorylation

A

ETC controls the release of energy for ATP synthesis.

3
Q

• Know the location of the electron transport chain and the multi-protein
complexes that make up the chain

A
  • ETC is in the inner mitochondrial membrane.
4
Q

• Know how the free energy of electrons change as they move through the
electron transport chain and combine with the final electron acceptor, oxygen,
to form water

A

Electrons drop in free energy as they go down the chain and

are finally passed to O2, forming H2O

5
Q

• Know the complexes to which NADH and FADH2 donate their electrons and
describe the path these electrons take as they travel through the electron
transport chain

A

• Electrons enter the Chain via Complex I or II depending on whether they
enter as NADH or FADH2
• Electrons are passed from electron donors to acceptors until they reach the
final electron acceptor, oxygen
• When oxygen accepts the electron, it is reduced to water

6
Q

• Describe how oxidation and reduction relates to the movement of electrons
through the electron transport chain

A

• Coenzyme Q: accepts electrons from Complexes I and II and is reduced
to CoQH2
• CoQH2 diffuses in the inner membrane, docks, and transfers electrons to
Complex III
• Complex III transfers electrons to Cytochrome c
• Cytochrome c is reduced, diffuses in the membrane, and interacts with
Complex IV

7
Q

• Describe the role of protons in the electron transport chain including the
region where they accumulate within the mitochondria

A

• Energy is released as electrons are passed from NADH and FADH2 to O2
• Released energy
Ø Reduces electron carriers in the chain
Ø Pumps protons into the intermembrane space via Complexes I, III and IV
• End result:
Ø Accumulation of protons in the intermembrane space

8
Q

• Describe the relationship between proton concentrations within the
mitochondria and ATP Synthase

A

• Protons want to diffuse down their concentration gradient but cannot pass
through the membrane
• Proton concentration gradient contains high potential energy
• Protons in the intermembrane space diffuse down their electrical and
concentration gradients through ATP Synthase into the matrix

9
Q

• Know the basic structure of ATP Synthase

A
ATP Synthase:
F1 subunit (upper subunit):
- catalyzes synthesis of ATP
F0 subunit (lower subunit):
- forms a channel that rotates as protons pass through it.
10
Q

• Describe how the movement of protons through ATP Synthase generates
ATP

A

• Rotation of F0 leads to rotation of F1 in the
mitochondrial matrix

• Rotation of F1 causes conformational
changes in ATP Synthase that allow it to
catalyze the synthesis of ATP from ADP and P

11
Q

How much ATP is generated through ETC and oxidative phosphorylation.

A

32 molecules