The outer boundary of the cell is known as the cell membrane. It is a vital component that separates the interior of the cell from the external environment. The cell membrane is selectively permeable, meaning it allows certain substances to pass through while blocking others.
The cell membrane is primarily composed of a double layer of lipids, known as the lipid bilayer, which contains proteins and carbohydrates. These components work together to regulate the movement of molecules in and out of the cell, maintain the cell’s shape, and facilitate communication with other cells.
In addition to the cell membrane, plant cells have an additional outer layer called the cell wall. The cell wall is rigid and provides extra support and protection to the cell. It is mainly composed of cellulose, a complex carbohydrate.
In summary, the outer boundary of the cell is the cell membrane, and in plant cells, it is supplemented by the cell wall. These structures are essential for maintaining the cell’s integrity and functionality.