NEET BIOLOGY

Detailed explanation-1: -Cell membranes act as a barrier and gatekeeper between two distinct areas. Due to their semi-permeable nature, only a small number of molecules may penetrate the lipid bilayer. Gas and small hydrophobic molecules, such as oxygen and and carbon dioxide can quickly pass through membranes.

Detailed explanation-2: -Protein machineries embedded in the membranes of our cells act as ‘gatekeepers’ controlling everything transported in and out of every cell in our bodies. Because these machineries, called membrane embedded proteins, are vital to the way our bodies function they are the target of at least 40% of drugs.

Detailed explanation-3: -The cell membrane, also called the plasma membrane, is found in all cells and separates the interior of the cell from the outside environment. The cell membrane consists of a lipid bilayer that is semipermeable.

Detailed explanation-4: -So the phospholipids are arranged in a double layer (a bilayer) to keep the cell separate from its environment. Lipids do not mix with water (recall that oil is a lipid), so the phospholipid bilayer of the cell membrane acts as a barrier, keeping water out of the cell, and keeping the cytoplasm inside the cell.