What is the nuclear membrane's role?

The nuclear membrane, also known as the nuclear envelope, plays a significant role in regulating the passage of substances between the nucleus and the cytoplasm. This double membrane structure is embedded with nuclear pores that selectively allow certain molecules, such as RNA and proteins, to enter or exit the nucleus. By controlling the movement of these materials, the nuclear membrane helps maintain the conditions necessary for processes like gene expression and replication of DNA.

While it might seem that packaging proteins or making ribosomes are roles associated with cellular components, those activities primarily occur in the rough endoplasmic reticulum and nucleolus, respectively. The structural integrity of the cell is indeed supported by various components, but the primary function of the nuclear membrane is specifically related to regulating what enters and leaves the nucleus, thus facilitating communication and material exchange essential for cellular function.