Aerobic Respiration

Section 3, Chapter 4

mitochondrion

If oxygen is available, pyruvic acid can continue through aerobic respiration inside the mitochondria

Pyruvic Acid(3 Carbon)

Aerobic Pathways Includes1. Citric Acid Cycle2. Electron Transport Chain (ETC)

Mitochondrion

mitochondria

Mitochondria are the powerhouse of cell.

Most ATP are synthesized within mitochondria

Mitochondria consists of two layers Outer Membrane Inner Membrane – the inner membrane is highly

folded into cristae. Cristae greatly increase the surface area for the ETC

Priming Pyruvic Acid for the Citric Acid Cycle

Before pyruvic acid can enter the CAC it must first be converted into acetyl CoA

Acetyl CoA is the substrate for the citric acid cycle.

For each pyruvic acid, this reaction produces 1 CO2 molecule 1 NADH molecule 1 Acetyl CoA

pyruvic acid

1 molecule of CO2 is released

NAD+

NADH

acetyl CoA

Coenzyme A

Citric Acid Cycle

The citric acid cycle occurs in the matrix of the mitochondrion.

acetic acidoxaloacetic acid

citric acid

acetyl coA

Conenzyme A released

+

Citric Acid Cycle3 NAD+

3 NADHFAD

FADH2

ADP + PATP

2CO2

Citric Acid CycleAcetyl CoA combines with oxaloacetic acid to form citric acid.

Citric acid is converted back to oxaloacetic acid

pyruvic acid

1 ATP

3 NADH = transports electrons to ETC

1 FADH2 = transports electrons to ETC

2 CO2

Products of the citric acid cycle include:

electron transport chain (ETC)The ETC is located on the inner membrane of mitochondria

An enzyme called ATP synthase forms ATP by attaching a phosphate to ADP

ATP synthase is powered by the transfer of e- along a chain protein complexes that form the ETC.

The ETC produces 32-34 ATP per glucose

Oxygen removes electrons from the final complex protein, so it is the final e- acceptor

ETC

1. NADH (and FADH2) transfer their electrons to the first complex protein.

2. e- are transported along the protein complexes of the ETC.

3. Energy from the e- transfer is used to pump H+ into the inner membrane space.

4. Oxygen removes e- from the last complex protein. Water is formed in this reaction.

5. The H+ gradient established by the ETC is used to power ATP Synthase.

6. ATP Synthase generates new ATP by adding a phosphate to ADP.

Electron Transport Chain

Products of Electron Transport Chain include 32-34 ATP and Water.

Lipids & Proteins can also be broken down and used for ATP synthesis

Most organic molecules are converted into acetyl CoA and enter the citric acid cycle as acetyl coA

End of Section 3, Chapter 4

catabolism of proteins, fats, & carbohydrates