Endomembrane System

∞ generated and posted on 2016.08.26 ∞

Series of membrane-bound organelles that are found inside of eukaryotic cells.

Endomembrane system members include the nucleus, rough endoplasmic reticulum, smooth endoplasmic reticulum, Golgi apparatus, various vesicles, lysosomes, phagosomes, phagolysosomes, and vacuoles.

Neither mitochondria nor chloroplasts, though membrane-bound organelles, are members of the endomembrane system. The plasma membrane, however, is a component of the endomembrane system though not strictly found "inside" of cells.

The membranes of endomembrane system members contact cytoplasm on one side and, except for the plasma membrane, possess what is known as a "lumen" on the other, where lumen represents the interior volume of an endomembrane system member. An exception to this "contacting cytoplasm" rule is found with the nuclear membrane which on one side contacts the interior of the nucleus rather than cytoplasm.