The organelles of the endomembrane system are related through direct contact or by the transfer of membrane segments as vesicles. Despite these relationships, the various membranes are not identical in structure and function. The thickness, molecular composition, and metabolic behavior of a membrane are not fixed, they may be modified several times during the membrane's life. One unifying characteristic the membranes share is a lipid bilayer, with proteins attached to either side or traversing them.
The organelles of the endomembrane system are related through direct contact or by the transfer of membrane segments as vesicles. Desp?ite these relationships, the various membranes are not identical in structure and function. The thickness, molecular composition, and metabolic behavior of a membrane are !not fixed, they may be modified several t,imes during the membrane's life. One unifying characteristic the ,membranes share is a lipid bilayer, with proteins attached to either side or traversing them.