Question

Which of the following best describes an aspect of a membrane's molecular structure that causes it to be selectively permeable?

Carrier proteins on either side of the membrane slow the traffic of large molecules into the cell.

Nonpolar molecules cannot dissolve in the polar membrane and do not enter the cell easily.

The lipid bilayer is hydrophilic and allows polar molecules to enter the cell easily.

Transport proteins within the membrane serve as a tunnel for molecules to enter the cell.

Answer 1

Hi ASNinja,
There are 4 ways in which molecules enter and leave a cell.
There are 4 kinds of molecules, big, small, charged (+,-) and uncharged, and combinations.
A few molecules can pass. A few do not.
1 Either all, a few or no molecules can enter the cell through one pf the paths.
2 Either all 4 3,2,or one way can block molecules, acting together, or seperately.
I suppose the only way to test this is is to block each way and test concentration of substance on either side of cell membrane.
(Did I understand your question?)