Fat Utilization and Lipolysis

Energy from Fats

• The brain does not use fats for energy.

Breakdown of Triglycerides

• Lipase is the main enzyme involved in breaking down triglycerides.
• Hormone-sensitive lipase (HSL) is stimulated by epinephrine (adrenaline) to break down triglycerides.
• When triglycerides are broken down, they release glycerol and fatty acids.

Lipolysis

• Glycerol is broken apart from fatty acids during lipolysis.
• Albumin is the transporter for free fatty acids in the blood.

Fatty Acid Transport

• Fatty acid-binding proteins are the primary transporters for fatty acids in muscle cells.
• Carnitine palmitoyltransferase I (CPT-I) is the enzyme that allows fatty acids to enter the mitochondria for energy production.

Fat as Energy Source

• Fats are primarily used for energy during rest because they provide a slow and steady release of energy.
• Fats are not the preferred fuel source during exercise because they are not quickly metabolized to produce energy.