Structure and Function of Endoplasmic Reticulum

The endoplasmic reticulum (ER) is one of the cell organelles. Organelle means ‘the little organs’. Organelles have a definite structure and defined functions in the cell and have the same status in the cell as the organs have in the body of an animal or a plant. The endoplasmic reticulum is an irregular network of double membrane tube-like structures, whose primary function is to provide a supporting framework to the cell. It is of two types – rough and smooth endoplasmic reticulum. In this post, we will learn about the structure and functions of both – the rough and the smooth endoplasmic reticulum.

Endoplasmic Reticulum

STRUCTURE AND FUNCTION OF ENDOPLASMIC RETICULUM

The endoplasmic reticulum (ER) is so fine in its structure that its existence within the cell is revealed only through an electron microscope.

Structure of Endoplasmic Reticulum

• It is an irregular network of double membrane tube-like structures distributed over the entire cytoplasm in a cell.
• It is continuous with the cell or plasma membrane on the outside and the nuclear membrane on the inside.
• At its outer end, the endoplasmic reticulum (ER) is connected with the cell membrane.
• At the inner end, it is connected with the nuclear membrane.
• It is continuous with the cell or plasma membrane on the outside and the nuclear membrane on the inside
• The endoplasmic reticulum is of two types – rough and smooth. It appears uneven when the particles-like ribosomes are attached to it and appear smooth without them.

Common Functions of Smooth and Rough Endoplasmic Reticulum

• Its primary function is to form the supporting framework of the cell.
• It also serves as a pathway for the distribution of the material (protein and fats) from one part of the cell to the other.

Specific Function of rough endoplasmic reticulum

• Due to the presence of the ribosome – proteins and lipids are synthesized on the rough endoplasmic reticulum, which helps in regenerating cell membranes. This process is known as membrane biogenesis. (‘Biogenesis’ means ‘generation of a substance by living matter’).

Structure and function of endoplasmic reticulum in tabular form

Structure and function of the endoplasmic reticulum (ER)

RIBOSOMES AND ITS FUNCTION

The ribosomes are numerous small granules either scattered freely in the cytoplasm or attached to the membranes of the endoplasmic reticulum. These are the single-walled dense, spherical bodies composed mainly of RNA (Ribonucleic Acid). The most essential function of the ribosome is protein synthesis. Therefore, they are also called ‘factories’ or ‘sites’ for the synthesis of proteins.

The video from Bodhaguru explains the structure and function of the endoplasmic reticulum using a 3D model.