The Aerobic system Flashcards
When is the aerobic system used?
- Used during rest and moderate intensity exercise where oxygen is readily available.
What are the fuel sources for the aerobic system?
- Glycogen, fats and proteins.
Why is the aerobic system good?
- Is the most preferred energy system.
- Most efficient at ATP re-synthesis= it produces 18x more energy than any of the anaerobic systems.
The process (3 stages)
Stage 1: Aerobic Glycolysis
Stage 2: The Krebs Cycle
Stage 3: Electron Transport Chain.
Stage 1: Aerobic glycolysis
Takes place in the sarcoplasm.
1. Glycogen (broken down by PFK).
2. Forms Glucose-6-phosphate.
3. Energy is released which produces 2 moles of ATP.
4. Pyruvate acid forms.
5. Sufficient oxygen is available.
6. Pyruvate combines with Coenzyme A to form Acetyl- coenzyme A.
7. Energy site changes from the sarcoplasm to the Mitochondria.
Stage 2: the Krebs Cycle
Takes place in the mitochondria.
1. Acetyl-coenzyme A leaves the sarcoplasm and enters the mitochondria.
2. Acetyl-coenzyme A combines with Oxaloacetic to form Citric acid.
3. Citric acid is oxidised to form Hydrogen, Carbon dioxide and 2 moles of ATP.
4. Hydrogen is sent to the Electron Transport Chain.
5. Carbon dioxide is sent to the lungs.
6. 2 moles of ATP are used in muscular contraction.
Stage 3: Electron transport chain
Takes place in the mitochondria.
1. Hydrogen atoms are split into ions and electrons.
2. They are charged with energy.
3. Hydrogen atoms combine with oxygen to form water.
4. Hydrogen electrons provide energy to resynthesise ATP (34 moles of ATP).
What is mitochondria?
- Powerhouse of the cell.
- ATP production during aerobic conditions.
- Lots of mitochondria available.
Where are the mitochondria found?
- Slow twitch muscle fibres.
What do the mitochondria do?
- Facilitate the breakdown of Glycogen and Fats in order to produce energy for ATP resynthesis.
What takes place in the mitochondria?
- The Krebs cycle and the Electron transport chain.
