ENDOPLASMIC RETICULUM

ENDOPLASMIC RETICULUM
Endoplasmic reticulum is an extensive network of interconnected channels and vesicles called cisternae, these membranous channels extends from the nuclear membrane into the cytoplasm. The membrane enclosed space between the cisternae is called the lumen of ER.

TYPES OF ENDOPLASMIC RETICULUM
On the basis of the presence or the absence of the ribosomes there are two types of ER

SMOOTH ENDOPLASMIC RETICULUM
The surface of smooth ER is devoid of the ribosomes, and thus called the smooth ER.

FUNCTION OF SMOOTH ENDOPLASMIC RETICULUM:

AS A TRANSPORT SYSTEM
The endoplasmic reticulum acts as an intracellular circulatory or transporting system. The channels help in the transport of material in the cell.

DETOXIFICATION OF TOXIC SUBSTANCE
Smooth ER helps in the detoxification of toxic substance in liver

LIPID METABOLISM:
Smooth ER helps in lipid metabolism.

ROUGH ENDOPLASMIC RETICULUM:
The surface of the rough ER is studded with ribosomes and thus is called as rough endoplasmic reticulum. RER is in direct contact with the nuclear membrane, and RER the nuclear membrane is also studded with ribosomes.

FUNCTION OF ROUGH ENDOPLASMIC RETICULUM:

SKELETAL FRAMEWORK:
The endoplasmic reticulum provides an ultra- structural skeleton frame work to the cell and gives mechanical support to the colloidal cytoplasmic matrix.
AS A TRANSPORT SYSTEM:
The endoplasmic reticulum acts as an intracellular circulatory or transporting system.
The channels help in the transport of material in the cell.
PROTEIN SYNTHETIC MACHINERY:
Rough ER helps in the synthesis of proteins.
FORMATION OF NUCLEAR ENVELOP:
The ER membranes from the new nuclear envelope after each nuclear division.