Lipids as an energy source
The utilization of lipids for energy production takes place in three basic phases:
- Lipid mobilization - hydrolysis of TAG to MK and glycerol and their transport blood.
- Activation of MK in the cytosol and their transport into the matrix mitochondria.
- β-oxidation - breaking down MK into acetyl~CoA, which enters the Krebs cycle, or ketone bodies are formed from it.
Lipid mobilization – lipolysis[edit | edit source]
The mobilization of stored lipids is enzymatically ensured by hormone-sensitive lipase' (HSL). It catalyzes the reaction:
- TAG → 3 MK + glycerol
Regulation of lipolysis[edit | edit source]
As the name suggests, the enzyme is under strict hormonal control. Its activity is stimulated by the ``phosphorylation of its molecule. Insulin as an anabolic hormone causes its inhibition, counterregulatory hormones (glucagon, catecholamines) or thyroid hormones on the contrary activate it.