Question

Answer the question ​

Answer 1

Answer:

cell membranes serve as barriers and gatekeepers.

Explanation:

They are semi- permeable , which means that some molecules can diffuse across the lipid bilayer but others cannot .... specialized proteins in the cell membrane regulates the concentration of specific molecules inside the cell.

Answer 2

The membrane that surrounds the organelles of the cell and protects them from external environment is called the plasma membrane. Plasma membrane is called selectively permeable membrane because it allows only selective substances for diffusion. Not all substances are allowed to diffuse.

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