Endocytosis and Exocytosis

Exocytosis: Vesicles, small sacs made of membranes, can transport and store substances within the cytoplasm. Exocytosis moves substances from cytoplasm to plasma membrane during secretion.

Endocytosis: Endocytosis encloses particles in small portions of plasma membrane to form vesicles that then move into the cytoplasm. Phagocytic cells (amoebas and white blood cells) digest the contents of the endocytic vesicles by means of enzymes within lysosomes which fuse with the vesicles.

This animation (Audio - Important) describes endocytosis and exocytosis.

REVIEW: Which of the following is NOT a form of active transport?
a. sodium-potassium pump
b. endocytosis
c. exocytosis
d. diffusion
e. none of these

Answer d