Question

What is one property of a molecule that determines whether it will pass through a selectively permeable membrane?

Answer 1

Size. The size of the molecule is probably the most important single characteristic. E.g., glucose is very small, and although there are specific transporters for glucose, it can diffuse through a typical selectively permeable membrane (like a cellular membrane). However whether or not a small molecule will pass through a membrane depends on its concentrations inside and outside the cell.

Answer 2

Thank you