6. Cell Membrane & Transport
Endocytosis and Exocytosis
Endocytosis Allows Entry to the Cell
Endocytosis and Exocytosis Example 1
Pinocytosis brings only water molecules into the cell, receptor-mediated endocytosis brings in other molecules also
Pinocytosis increases the surface area of the plasma membrane, receptor-mediated endocytosis decreases it
Pinocytosis is nonselective, receptor-mediated endocytosis offers more selectivity
Pinocytosis can concentrate substances from the extracellular fluid, receptor-mediated endocytosis cannot
Exocytosis Allows Exiting from the Cell
It forms intracellular vesicles from inward folding of the plasma membrane.
It requires fusion of vesicles with the plasma membrane.
It secretes large molecules out of the cell.
It is responsible for removing large waste particles that cannot be recycled by the cell.