Final Answer:
As the molecular weight of a molecule increases, its D) membrane permeability decreases.
Step-by-step explanation:
The permeability of a molecule through biological membranes is often influenced by its molecular weight. Larger molecules typically have a harder time crossing cell membranes compared to smaller ones. This is particularly evident in the lipid bilayer, where smaller, non-polar molecules can diffuse more readily than larger ones.
Options A, B, C, and E do not align with the expected behavior based on molecular weight. Concentration in a solution (Option A) depends on factors like solubility, and the rate of diffusion (Option B) generally decreases with increased molecular weight. The ability to dissolve in lipids (Option C) may not necessarily increase, and the ability to form a charge (Option E) depends on the specific molecule.
Option D) Membrane permeability decreases is the answer.