The nuclear side of the envelope is lined by the nuclear lamina, which is a netlike array of protein filaments that keep the shape of the nucleus. Also within is the chromatin, a material that organizes DNA and proteins. When the cells beginnings to reproduce, the chromatin condenses becoming thick separate structures know as chromosomes. Ribosomes consist of two sub units and functioning as the site of protein synthesis in the cytoplasm. Free ribosomes function in the cytosol, while bound ribosomes generally make proteins that are for inclusion into the membrane, packaging, or for export from the cell.
Endoplasmic reticulum makes up more then half the membrane of the cell.
Smooth endoplasmic reticulum appears to be smooth because it lacks ribosomes on the cytoplasmic surface. Yet the other endoplasmic reticulum appears rough because ribosomes stud the cytoplasmic surface. After leaving the endoplasmic reticulum, many transport vesicles travel to the Golgi apparatus. This apparatus consists of flattened membranous sacs. This is the center of manufacturing, warehousing, sorting and shipping.