Question

What controls the flow of substances in and out of a cell?

Answer 1

Transport of material in cells:

1. Many substances move in or out of the cell through passive and active transport.
2. If the molecule can transport without the requirement of energy, then the movement is called passive transport. Diffusion, osmosis etc., are examples of passive transport.
3. If the transport of materials is done by utilising energy, then the transport is called active transport.

Cell membrane:

1. Cell cytoplasm is surrounded by a phospholipid bilayer called cell membrane.
2. Proteins are found embedded in the cell membrane.
3. Cell membrane is important because it controls the movement of substances across it.