Afunction of cell membranes in humans is the

Functions of the cell membrane in humans include:

1. It maintains the physical integrity of the cell by enclosing the cytoplasm and organelles within it.

2. Forms a barrier between the inside of the cell and the environment outside the cell, enabling different chemical environments to exist on each side of the cell.

3. Active transport. The cell membrane allows active transport  of specific molecules across the cell membrane in either direction, that is into or out of the cell.

4. Holds  embedded surface protein markers which serve to identify the cell enabling cells to communicate with each other.

a scenario where a cell may be needed to perform a form of endocytosis is when transporting large molecules. a scenario where a cell may be needed to perform a form of exocytosis is when releasing the large molecule from the cell.