TRANSPORT – Endo/Exo cytosis
Endocytosis – Used for bulk transport of substances into the cell, via the creation of a vesicle using ATP energy
Process:
- The cell surface membrane engulfs the solid/liquid bulk material
- Part of the phospholipid membrane bilayer forms this vesicle
- The vesicle carries the contents into the cell
TYPES of endocytosis
- Phagocytosis – (cellular eating) a cell engulfs a particle and packages it within a food vacuole.
- Pinocytosis – (cellular drinking) a cell “gulps” droplets of fluid by forming tiny vesicles
- Receptor-mediated endocytosis – a cell takes in very specific molecules based upon receptor proteins in the membrane that bind the molecules to be included in the vesicle
Exocytosis – Used for bulk transport of substances out of the cell (e.g. waste products), via the creation of a vesicle using ATP energy
Process:
- The vesicle carries the contents towards the membrane
- The cell surface membrane fuses with the vesicle à the vesicle becomes part of the bilayer
- The contents are released out of the cell
