Molecules are continuously transported across the cells. Some of them need proteins and energy to travel across the cell. Transportation of the molecules is carried out by two processes:
- Active Transport – It requires the expenditure of The energy used is in the form of ATP molecules. The transportation is carried out by protein molecules present on the cell membrane.
Passive Transport – It does not require energy and carries out the movement of molecules without spending energy. Diffusion is a type of passive transport.