AP BIOLOGY

Detailed explanation-1: -By acting as a gatekeeper, the plasma membrane protects the cell from its surroundings and keeps important molecules from leaving the cell, so that the correct balance of molecules is maintained.

Detailed explanation-2: -Cell membrane The cell membrane encloses the cell. It acts like a gatekeeper-allowing some materials to pass through it, but not others. throughout the cytoplasm are Word Watch!

Detailed explanation-3: -Cell membranes serve as barriers and gatekeepers. They are semi-permeable, which means that some molecules can diffuse across the lipid bilayer but others cannot. Small hydrophobic molecules and gases like oxygen and carbon dioxide cross membranes rapidly.

Detailed explanation-4: -A membrane is the cell’s interface with the rest of the world-it’s gatekeeper, if you will. This phospholipid bilayer determines what molecules can move into or out of the cell, and so is in large part responsible for maintaining the delicate homeostasis of each cell.

Detailed explanation-5: -Plasma membranes must allow certain substances to enter and leave a cell, while preventing harmful material from entering and essential material from leaving. In other words, plasma membranes are selectively permeable-they allow some substances through but not others.