Aerobic Energy Pathways

Question 1

Outline the process of the ‘Slow glycolysis’ cycle.

Answer 1

• In aerobic conditions, this is the first stage of respiration.
• In the presence of oxygen, pyruvate diffuses via active transport into the mitochondrial matrix.
• Pyruvate is oxidised + converted into Acetyl co-enzyme A.

Question 2

Where to the process of glycolysis (fast + slow) occur?

Answer 2

Cytoplasm.

Question 3

What are the products produced during ‘Slow glycolysis’?

Answer 3

• 2 ATP (net)
• 2 NADH (hydrogen transporter)
• Carbon dioxide.

Question 4

Outline the process of the Krebs cycle.

Answer 4

1. Acetyl co-enzyme A + oxaloacetate acid combine to release further Acetyl co-enzyme A + citric acid.
2. When released the co-enzyme A is recycled.
3. Combines with pyruvate to create more co-enzyme A’s.
4. CO2 is released from citric acid.
5. Hydrogen is released + combined with NAD to form NADH.
6. CO2 continuous to be progressively lost.

Question 5

What can the Krebs cycle also be referred to as?

Answer 5

The Citric Acid Cycle.

Question 6

What are the products produced during the Krebs cycle?

Answer 6

• 10 NADH (net)
• 2FADH (net)

Question 7

Outline the process of the Mitochondrial chemiosmotic mechanism/Electron transport chain.

Answer 7

1. Hydrogen atoms are ionized.
2. ‘Freed’ electrons enter the Electron transport chain of ‘electron acceptors’ and reach cytochrome oxidase.
3. During electron transport, energy is released for ATP replenishment.
4. Energy, pumps Hydrogen ions out of the mitochondrial matrix and into the Intermembrane space.
5. Chemical and voltage gradient created, causes hydrogen ions to drive the use of the ATPase mechanism.
6. Energy from this ‘flow’ is used to convert ADP→ATP.
7. ATP moves to the cytoplasm.

Question 8

What are the products produced after the Glycolysis, Krebs cycle and Electron Transport Chain?

Answer 8

30 to 32 ATP.

Question 9

Outline the aspects of the aerobic energy pathway.

Answer 9

• Oxygen-dependent metabolism.
• Has glycolytic and lipolytic components.
• Reliant on both muscle glycogen and blood glucose.
• Preferential pathway for exercise longer than 2 minutes.

Question 10

What are activities where the aerobic energy system would be primarily used?

Answer 10

• 1500m.
• 5km run.
• Marathon.

Question 11

What are the 3 stages of the aerobic energy system?

Answer 11

1. Glycolysis.
2. Krebs Cycle.
3. Electron Transport System.