Final answer:
Glucose inhibits the entry of fatty acids into the mitochondria and subsequent fatty acid oxidation by inhibiting the enzyme CPTI. High glucose levels favor the use of glucose as an energy source over fatty acids. This ensures energy balance and efficient use of different energy sources.
Step-by-step explanation:
The entry of fatty acids into the mitochondria and subsequent fatty acid oxidation is inhibited by glucose. Glucose inhibits the enzyme carnitine acyltransferase I (CPTI), which is responsible for attaching the fatty acyl-CoA to carnitine for transport into the mitochondrial matrix. This inhibition prevents the fatty acids from entering the mitochondria and being oxidized for energy production.
When glucose levels are high, the body preferentially uses glucose as a source of energy instead of fatty acids. This is because glucose metabolism is more efficient and produces more ATP per molecule than fatty acid oxidation. Therefore, the presence of glucose inhibits fatty acid oxidation.
Overall, glucose acts as a regulator of fatty acid metabolism, ensuring that fatty acids are only oxidized when glucose levels are low. This allows for energy balance and efficient use of different energy sources by the body.