Question

What are lipid rafts? What isn't present?

A) Stable membrane domains; lack cholesterol
B) Dynamic membrane regions; absence of proteins
C) Microscopic lipid clusters; no sphingolipids
D) Fluid membrane regions; absence of saturated fatty acids

Answer 1

Lipid rafts are stable membrane domains composed of specific lipids, including sphingolipids and cholesterol. They play important roles in cellular processes such as signal transduction and membrane trafficking. Lipid rafts are not present in fluid membrane regions lacking saturated fatty acids.

Step-by-step explanation:

Lipid rafts are stable membrane domains that are composed of specific lipids, including sphingolipids and cholesterol. These lipid rafts play important roles in various cellular processes, such as signal transduction and membrane trafficking. They can act as platforms for the clustering of proteins and the localization of specific molecules.

In this context, lipid rafts are not present in fluid membrane regions where there is an absence of saturated fatty acids. Saturated fatty acids tend to make the membrane more rigid and less fluid, whereas unsaturated fatty acids introduce kinks in the carbon chain, increasing the membrane's fluidity.