Question

Write a note on exocytosis and endocytosis.

Answer 1

Hint:Both endocytosis and exocytosis are active transport methods that help in transporting materials from inside to the outside of the cells and vice versa.

Complete answer
Exocytosis- The movement of materials from within the cell to the exterior of the cell is called exocytosis. It is an active transport since it requires energy. The agents of transportation are membrane-bound vesicles containing cellular molecules that are transported across the cell membrane. The vesicles are bound with the cell membrane and squirt their content out. This process is important for expelling excess water from the cell transporting chemical messages between the cells and for rebuilding the cell membrane. The vesicles involved in the transportation are made by Golgi apparatus, endosomes and presynaptic neurons. It can be brought about with the help of three pathways constitutive exocytosis, regulated exocytosis and lysosome mediated exocytosis. The vesicles carrying the waste products from the cell are sent to the cell membrane which then attaches the vesicles to itself and their fusion causes the release of the vascular contents outside the cell.

Endocytosis- endocytosis is a transport method with which the contents from the outer side of the cell are able to transport into the cell like large molecules parts of cells, wholesales, hormones, stimuli etc. it is an active process since it requires energy. When the target particle reaches the plasma membrane it forms a pocket around the particle the pocket pinches resulting in a particle being contained in a newly created intracellular vesicle that is formed from the plasma membrane.

Note: Endocytosis and exocytosis involve transport through the semi permeable plasma membrane. Apart from this there are many different types of transport seen in cells.