Question

Which one of the following is not a correct statement regarding the design of biological membranes?

• A. Carbohydrate molecules associated with membranes tend to be associated with protein molecules embedded in the membrane
• B. Hydrophobic ends of phospholipid molecules in the outer monolayer of the membrane are exposed directly to the extracellular environment
• C. Cholesterol is a type of lipid frequently found in membranes of animal cells
• D. Protein molecules can be located on the inner and outer surfaces of the membrane as well as traverse the entire thickness of the bilayer

Answer 1

The correct option is B Hydrophobic ends of phospholipid molecules in the outer monolayer of the membrane are exposed directly to the extracellular environment

In a cell membrane, the hydrophobic ends of phospholipid molecules in the outer monolayer of the membrane are sandwiched between the hydrophilic heads of the phospholipid bilayer and are not exposed to the extracellular environment.

So, the correct answer is 'Hydrophobic ends of phospholipid molecules in the outer monolayer of the membrane are exposed directly to the extracellular environment'.