Question

What is the primary way that lipids are transported though the bloodstream?

1) As free fatty acids
2) As lipoproteins
3) As cholesterol
4) As triglycerides

Answer 1

Lipids are primarily transported through the bloodstream as lipoproteins, which are complexes of lipids and proteins that allow these insoluble molecules to move in an aqueous environment. Chylomicrons transport dietary triacylglycerols, while other classes such as LDL and HDL are involved in cholesterol transport.

Step-by-step explanation:

The primary way that lipids are transported through the bloodstream is as lipoproteins. These molecules are complexes of lipids and proteins, with the lipids being nonpolar and insoluble in water. Lipoproteins include classes such as chylomicrons, very low-density lipoproteins (VLDL), low-density lipoprotein (LDL), and high-density lipoproteins (HDL), each with distinct functions and lipid-to-protein ratios.

Chylomicrons are responsible for transporting lipids from digestion into the bloodstream and are the form in which dietary triacylglycerols are carried. They encounter lipoprotein lipase, which breaks down triacylglycerols into fatty acids and glycerol, allowing them to be used for energy or stored. In contrast, LDL and HDL are key in the transport of cholesterol. This complex system ensures that lipids can be moved throughout the body in a water-soluble format.