Cell membranes are said to be ________ because they allow some substances to pass but not others.
A)extremely thin
B)a phospholipid bilayer
C)selectively permeable
D)sensitive to the environment
E)physically isolating

Question

Quizplus · Accepted Answer

Cell membranes are selectively permeable, meaning that they only allow certain molecules to pass through, while others are blocked. This is due to the structure of the membrane, which is composed of a phospholipid bilayer that has a hydrophobic (water-repelling) interior and a hydrophilic (water-attracting) exterior. This structure allows small, nonpolar molecules such as oxygen and carbon dioxide to pass freely, while larger or charged molecules require special transport proteins to facilitate their passage. This selectivity is essential for the proper functioning of cells and helps maintain the internal environment necessary for life.

Cell Membranes Are Said to Be ________ Because They Allow