Oxidative phosphorylation

1
Oxidative phosphorylation

• Oxidative Phosphorylation electron transport
  chain and chemiosmosis
• e- trasport chain embedded in INNER mito membrane
• Composed of 3 transmembrane H pumps
• Electrons flow through e- chain
• Loss of energy from e-s powers H pump
• O2 is final electron acceptor, no O2 no e-
  chain

2
Electron Transport Chain ATP Synthase
3
Electron Transport Chain

• H ions flow back down gradient through ATP
  synthase
• ATP synthase harnesses the proton motive force
• ATP synthase adds a P to ADP to make ATP
• Do you think the inner mito membrane is permeable
  to H ions?
• This is the process of chemiosmosis

4
Chemiosmosis
5
Chemiosmosis

• Chemiosmosis an energy-coupling mechanism that
  uses energy stored in the form of an H gradient
  across a membrane to drive cellular work.
• The e- chain and chemiosmosis together make up
  the process of oxidative phosphorylation
• ATP is phosphoralayted
• Oxygen is necessary
• ATP/Glucose is 36-38,
• Oxidative phosphorylation produces 32-34 alone.

6
ATP Yield / Phase of Respiration
7
Remember

• Aerobic respiration uses oxygn

8
A few alternatives

• When O2 is not present

9
Fermentation

• Production of ATP w/o O2
• This is ANAerboic respiration
• Glycolysis still in the picture
• Rember O2 not needed for glycolysis
• NAD is electron acceptor
• Two common types
• Alcohol fermentation
• Lactic acid fermentation

10
Alcohol Fermentation

• Pyruvate converted to ethanol, releasing CO2
• NADH is oxidized to make NAD

11
(No Transcript)
12
Lactic Acid Fermentation

• Pyruvate reduced by NADH
• So did it gain or loose electrons?
• Lactate is formed as waste product.

13
(No Transcript)
14
Facultative Anerobes

• Organisms that can do aerobic respiration when
  possible
• Can switch to fermentation under aerobic
  conditions

15
Glycolysis and Citric Acid Cycle

• Intermediates of these processes can be diverted
  into a number of other anabolic pathways
• Biosynthesis is the production of macromolecules
• Many other compounds can be used to make ATP in
  cellular respiration
• Other sugars
• Proteins
• fats

16
Try these on for size

• Explain the specific role of glycolysis in
  cellular respiration.
• Describe the function of water in cellular
  respiration and photosynthesis.