It brings big materials from out side the cell to the inside.
Materials get into the cell by active and passive transport are the ones that are relatively small in size. This is for these materials to go through the gates in the . If a material is big in size like a bacterial cell for example and the cell needs to take it in, then active and passive transport through the membrane will not work as the bacterial cell cannot be pushed into the cell through these openings. When a bacterial cell gets into the human blood, the immune system needs to get rid of it, and to do so the white blood cells need to engulf it so they can digest it. To engulf this an endocytic vesicle should be formed around it then this vesicle is detached from the cell membrane to the inside of the cell so the bacteria can be digested. another example of using endocytic vesicles is the engulfing of food particles from a pond by unicellular organisms like euglena and paramecium.
