Question

11-19 Although membrane proteins contribute roughly 50% of the total mass of the membrane,

there are about 50 times more lipid molecules than there are protein molecules in cellular
membranes. Explain this apparent discrepancy.

Answer 1

The apparent discrepancy between the number of lipid molecules and protein molecules in cellular membranes is due to the difference in mass contribution and concentration. Lipids are smaller molecules that are densely packed in the membrane, while proteins are larger and occupy more space.

Step-by-step explanation:

The apparent discrepancy between the number of lipid molecules and protein molecules in cellular membranes is due to the difference in mass contribution and concentration.

Membrane proteins contribute roughly 50% of the total mass of the membrane, while lipid molecules are present in much higher quantities. This is because lipids are smaller molecules that are more densely packed in the membrane, while proteins are larger and occupy more space.

For example, let's consider a hypothetical membrane with 100 lipid molecules and 2 protein molecules. The mass contribution of lipid molecules would be 98%, while the mass contribution of protein molecules would be 2%.

However, in terms of concentration, there are about 50 times more lipid molecules (100) than protein molecules (2) in this membrane.