AP BIOLOGY

Detailed explanation-1: -The cell membrane is semipermeable to small, uncharged molecules like oxygen and carbon dioxide. It is selectively permeable to molecules the cell needs, such as glucose, amino acids, and more.

Detailed explanation-2: -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-3: -A semipermeable membrane is a barrier that will only allow some molecules to pass through while blocking the passage of other molecules. A semipermeable barrier essentially acts as a filter. Different types of semipermeable membranes can block out different sized molecules.

Detailed explanation-4: -The plasma membrane is known as semi-permeable because it regulates the movement of substances in and out of the cell. This means that the plasma membrane allows the entry of only some substances and prevents the movement of some other materials.

Detailed explanation-5: -An example of a semi-permeable membrane is a lipid bilayer, on which is based the plasma membrane that surrounds all biological cells. Many natural and synthetic materials thicker than a membrane are also semipermeable. An example of this is the thin film on the inside of an egg.