Nuclear Membrane

All the eukaryotic cells that are found in plants, animals, fungi and protists have a control center, called as nucleus where DNA is stored. Every nucleus is surrounded and covered by a double-layered membrane, known as the nuclear membrane or nuclear envelope. This membrane separates the nucleoplasm, fluid present in the nucleus through the cytoplasm.


A nuclear membrane is made up two membrane – an outer and an inner membrane. Each membrane consists of phospholipids that are arranged in a bilayer. The complete nuclear membrane includes four rows of phospholipids. The perinuclear space separates in inner and outer membrane. The outer nuclear membrane works with the rough endoplasmic reticulum. It is an organelle which is important in transportation of proteins.

Endoplasmic Reticulum

The rough endoplasmic reticulum and the outer membrane both are covered in ribosomes as these are the actual location of protein synthesis. The nuclear lamina is attached to the inner nuclear membrane on the nucleoplasm. The nuclear lamina also connects to and anchors chromatin which are arranged loosely in DNA and protein structure. A layer of proteins that gives strength and support to the nuclear membrane.

Functions of Nuclear Membrane

  • Nuclear envelope has small holes which are known as nuclear pores. These pores allow the content to move in and out of the nucleus. Also, used as connector for inner membrane and outer membrane.
  • The surface area of the nuclear envelope expands and doubles the nuclear pores during the inter phase portion of cell division.
  • This membrane covers the nucleus with a double membrane by multiple pores. These pores helps in regulating the passage of macro-molecules such as RNA and proteins and allow free passage of water, ATP, ions and small molecules. The membrane takes some control over the flow of information in the cell as it is carried by the macro molecules.

Practise This Question

Which of the following is an IUD?