explain the difference between endocytosis and exocytosis and provide an example of a molecule (remembering to state its function) that is transferred using this method.
Endocytosis and exocytosis are the processes by which cells move materials into or out of the cell that are too large to directly pass through the plasma membrane. Endocytosis is the process of capturing a substance or particle from outside the cell by engulfing it with the cell membrane, and bringing it into the cell. Exocytosis is the process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell.
By the process of endocytosis cells take up plasma membrane components, fluid, solutes, macromolecules, and particulate substances. Endocytosed cargo includes receptor–ligand complexes, a spectrum of nutrients and their carriers, extracellular matrix components, cell debris, bacteria, viruses and other cells. Through endocytosis, the cell regulates the composition of its plasma membrane in response to changing extracellular conditions. Through the process of exocytosis the secretory pathway delivers newly synthesized proteins, carbohydrates, and lipids either to the plasma membrane or the extracellular space.
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