Question

List the function of rough and smooth endoplasmic reticulum and Golgi bodies?

Answer 1

Hint: Endoplasmic reticulum is the network of reticulum of tiny tubular structures scattered in the cytoplasm. Golgi bodies are densely stained reticular structures present near the nucleus of the cell and it was first observed by Camillo Golgi in 1898.

Complete answer:
The interior of the eukaryotic cell is composed of many membrane bound organelles and have distinct structure and function. The Endoplasmic reticulum, Golgi complex, Lysosomes and Vacuoles function in a coordinated manner and constitute an endomembrane system.
Endoplasmic Reticulum is composed of three parts:
> Cisternae
> Tubules
> Vesicles
On the basis of presence or absence of ribosomes on the surface of endoplasmic reticulum, it is divided into two types:
Smooth or agranular endoplasmic reticulum (SER): The ribosomes are not present on the surface of this endoplasmic reticulum. When it is observed under the electron microscope it appears as smooth tubular structure.
Functions:
It is specialized in the synthesis of lipids and steroids.
It is involved in the detoxification of drugs.
It is associated with muscle contraction by release and uptake of Ca ions.
It transfers the synthetic products of RER to Golgi bodies.
Rough endoplasmic reticulum (RER): The ribosomes are present on the surface of this endoplasmic reticulum and it gives a rough granular appearance under the electron microscope. RER contains two types of glycoprotein i.e., Ribophorin-1 and Ribophorin-2.
Functions:
> It is actively involved in protein synthesis and secretion.
> It provides the precursors of enzymes for the formation of lysosomes in the Golgi complex.
> It gives rise to Smooth endoplasmic reticulum.
Golgi apparatus is composed of four parts:
> Cisternae
> Tubules
> Vesicles
> Golgian vacuoles
Functions:
The important function of Golgi bodies is to process, package and transport the material for secretion.
It is the important site of formation of glycoprotein and glycolipids.
Root cap is rich in Golgi bodies which secrete mucilage for the lubrication of root tip.
Acrosome of the sperm is modified Golgi apparatus.
It is involved in the formation of plasma membranes during cytokinesis.

Note: The muscle cells are also rich in a smooth type of endoplasmic reticulum which is known as Sarcoplasmic reticulum. Golgi bodies are present in all eukaryotic cells except sieve tubes of plants, mature RBCs of mammals, sperm cells of bryophytes.