1. Nuclear membrane, the core of the nuclear envelope It consists of two cellular membranes called the inner nuclear membrane: and outer nuclear membrane, arranged parallel and separated to each another The outer nuclear membrane is directly continuous with the er and associated with enzymes characteristic of the ER and studded with ribosomes on its cytoplasmic surface so it is functionally similar to the rer The inner surface of the inner nuclear membrane is bound to a dense filamentous nuclear lamina meshwork Two nuclear membrane at as a barrier that separates the contents of the nucleus from the cytoplasm. Other molecules except small nonpolar molecules are unable to diffuse through both them, as lipid bilayer membranes1. Nuclear membrane, the core of the nuclear envelope It consists of two cellular membranes , called the inner nuclear membrane and outer nuclear membrane, arranged parallel and separated to each another. The outer nuclear membrane is directly continuous with the ER and associated with enzymes characteristic of the ER and studded with ribosomes on its cytoplasmic surface, so it is functionally similar to the RER. The inner surface of the inner nuclear membrane is bound to a dense filamentous nuclear lamina meshwork. Two nuclear membrane at as a barrier that separates the contents of the nucleus from the cytoplasm. Other molecules except small nonpolar molecules are unable to diffuse through both them, as lipid bilayer membranes