Cells have many structures inside of them called organelles. These organelles are like the organs in a human and they help the cell stay alive. Each organelle has it's own specific function to help the cell survive. The nucleus of a eukaryotic cell directs the cell's activities and stores DNA.
The endomembrane system has the different membranes that are suspended in the cytoplasm within a eukaryotic cell. The membranes divide the cell into functional and structural compartments, or organelles.