Fuel sources during aerobic respiration

Question 1

What are the 3 fuels used in Aerobic energy production?

Answer 1

• Glycogen
• Triglycerides
• Proteins

Question 2

Triglycerides

Answer 2

Triglycerides are fats stored in the muscle.

The process:
- Triglycerides are broken down into fatty acids.
- Fatty acids are broken in the sarcoplasm by a process called beta-oxidation (the fat equivalent of glycolysis) into acetyl CoA.
- Acetyl CoA enters the Krebs cycle and then the Electron transport chain to produce 36 moles of ATP along with CO2 and water.

Question 3

What is beta-oxidation?

Answer 3

• Beta-oxidation is the fat equivalent of Glycolysis.
• it turns fatty acids into Acetyl CoA.

Question 4

Protein

Answer 4

• Protein is converted into Amino acids.
• Amino acids are converted into Acetyl CoA.
• Acetyl CoA enters the Krebs cycle then the Electron transport chain.

Question 5

Advantages

Answer 5

1. More ATP can be resynthesized- 36 moles compared with 2 (18x more).
2. The body has large stores of both glycogen and fats which means exercise can last for several hours.
3. Oxidation of glycogen and fatty acids does not produce fatiguing by-products.

Question 6

Disadvantages

Answer 6

1. Takes a while for sufficient O2 to become available, therefore the system cannot be used in the short term.
2. Using fatty acids requires 15% more oxygen in order to break them down into Acetyl CoA.
3. Fats can only be used in the presence of glycogen. If glycogen runs out the body tries to used fat stores by themselves which causes the muscles to spasm (hitting the wall).