Intracellular membrane traffic: the cells constantly adjust the composition of cell membranes in response to need, exocytosis process of transport to the outer environment of the cell. It involves delivery of newly produced carbohydrates and lipids to the plasma membranes and extracellular space: endocytosis transport in direction of the cytosol. Involves removal of the cell membrane components and their subsequent delivery to endosomes. The transported components are either relocated to other membrane areas or degraded in lysosomes. Endocytosis is also used for nutrients capture: lumen interior space of each membrane enclosed compartment, transport vesicle structure used for transporting molecules. That is achieved by specific composition of vesicle outer membranes: secretory pathway transport from endoplasmic reticulum towards. The presence of molecular markers used for guiding traffic in order to ensure fusion with correct vesicles: as membranes may have some similar markers, their identity is defined by an assembly of marker molecules, not by single markers.