Question

Lipoproteins are like suitcases that move cholesterol, fatty acid remnants, triglycerides, and phospholipids from one place to another in the body. Given what you know about the insolubility of lipids in water, which of the four kinds of lipids would you predict to be on the outside of a lipoprotein clump, bathed in the water-based fluid portion of blood?

Answer 1

Phospholipids are likely to be found on the outside of a lipoprotein clump, making contact with the water-based fluid in blood due to their hydrophilic properties, while the hydrophobic tails hide the other lipids and cholesterol inside.

Step-by-step explanation:

Considering the insolubility of lipids in water, phospholipids would be predicted to be on the outside of a lipoprotein particle, bathed in the water-based fluid portion of blood. Phospholipids have a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails. Therefore, in a lipoprotein particle, phospholipids are oriented in such a way that the hydrophilic heads are exposed to the aqueous environment while the hydrophobic tails face inward, mingling with the cholesterol and other lipids.

This special orientation allows lipoproteins to be soluble in the blood, a necessity for the transportation of lipids through the bloodstream. The proteins associated with lipoproteins, known as apolipoproteins, further contribute to the solubility and function in the body's lipid transport system. In essence, lipoproteins are perfectly designed for their role as lipid carriers in an otherwise inhospitable water-based environment.