Free fatty acids are transported in the body through two main mechanisms: either bound to serum albumin or as part of triacylglycerols within lipoproteins.
Transport Mechanisms of Free Fatty Acids
Here's a breakdown of how these transport mechanisms work:
1. Binding to Serum Albumin
- Unesterified fatty acids (free fatty acids) are not water-soluble. Therefore, they cannot travel freely in the bloodstream.
- Serum albumin, a protein found in blood plasma, binds to these free fatty acids.
- This binding allows the fatty acids to be transported from one organ to another.
- This form of transport is used for relatively short-distance movement of fatty acids.
2. Incorporation into Triacylglycerols within Lipoproteins
- Triacylglycerols (also known as triglycerides) are esters of glycerol and three fatty acids. They are a compact form of fat storage.
- Free fatty acids can be converted into triacylglycerols.
- These triacylglycerols are then packaged into lipoproteins.
- Lipoproteins are complex particles containing lipids and proteins, that allow the transport of lipids in the blood.
- Lipoprotein lipase, an enzyme located on the surface of cells, then hydrolyzes these triacylglycerols back into free fatty acids.
- The free fatty acids can then be taken up by the cells.
Summary Table of Transport Mechanisms
| Transport Mechanism | Form of Fatty Acid | Carrier | Location of Action |
|---|---|---|---|
| Serum Albumin | Free Fatty Acids | Serum Albumin Protein | Bloodstream |
| Lipoproteins | Triacylglycerols | Lipoproteins | Bloodstream & Cell Surface |
Practical Insights
- The use of serum albumin for transport provides a rapid mechanism for the delivery of free fatty acids.
- The lipoprotein pathway is essential for transporting large quantities of lipids from organs like the liver and intestines to other tissues, where they can be used for energy or storage.
