exocytosis and endocytosis

endocytosis

• living cell taking in of matter by a membrane folding to form a vacuole

• take in bulk or large substances by the membrane folding in

• does not cross the membrane

• moves INTO the cell

endocytosis process

• The plasma membrane folds inward that fills with substances

• The plasma membrane folds back on itself to trap the fluid inside the vesicle (storage)

• The vesicle is pinched off from the membrane, then processed by the cell

phagocytosis

• type of endocytosis

• “eats” large and solid materials

pinosytosis

• type of endocytosis

• “eats” fluid material around it

exocytosis

• contents of a cell vacuole are released to the exterior (outside environment) through fusion of the vacuole membrane with the cell membrane

• large or bulk substances leaving the cell

• moves OUT of the cell

• does not pass through membrane

exocytosis process

• The vesicle membrane attaches to the cell membrane

• Vesicles transported from within the cell to the cell membrane

• Fusion of the vesicle membrane with the cell membrane releases the vesicle contents outside the cell

phagocytosis virus process

• The virus and the cell come in contact

• virus binds to the cell surface receptors on the macrophage

• macrophage starts to surround the virus and engulf it into the cell

• surrounded virus becomes completely enclosed in a bubble-like structure, called a “phagosome”, within the cytoplasm

• phagosome fuses with a lysosome, becoming a “phagolysosome”.

virus infection cycle

• virus gets into cell during endocytosis

• goes into nucleus

• new virus leaves cell through exocytosis