Primary Active Transport - Endocytosis

Endocytosis

Endocytosis is the process by which cells take in materials. The cellular membrane folds around the desired materials outside the cell. The ingested particle becomes trapped within a pouch, vacuole or inside the cytoplasm. Often enzymes from lysosomes are then used to digest the molecules absorbed by this process.

Biologists distinguish two main types of endocyctosis: pinocytosis and phagocytosis.

• In pinocytosis, cells engulf liquid particles (in humans this process occurs in the small intestine, cells there engulf fat droplets).
• In phagocytosis, cells engulf solid particles.