Question

Integral cell membrane proteins?

• A. Are partially embedded in lipid layer
• B. Are completely embedded in lipid layers
• C. Show lateral but not vertical movements with bilayer of lipid
• D. All of these

Answer 1

The correct option is B Are completely embedded in lipid layers

The fluid mosaic model explains various observations regarding the structure of functional cell membranes. According to this model, there is a lipid bilayer in which the protein molecules are embedded. The lipid bilayer gives fluidity and elasticity to the membrane. Small amounts of carbohydrates are also found in cell membrane. The cell is made up of two different types, or “classes”, of proteins. Integral proteins are nestled into the phospholipid bilayer and stick out on either end. Integral proteins are helpful for transporting larger molecules, like glucose, across the cell membrane. They have regions, called “polar” and “nonpolar” regions, that correspond with the polarity of the phospholipid bilayer.

So the correct option is 'are completely embedded in lipid layers'.