MINISTRY OF DEFENCE

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  MINISTRY OF DEFENCE. Establishment Of National University In Islamabad Total position. 29 Domicile , All over Pakistan    Qualification  intermediate to bachelor positions . Project Engineer(Civil) account Officer  supervisor assistant office boy     How to apply.   Apply online through the link https://www.fgei-cg.gov.pk/nup-rec.php   Last date to apply  02 April 2023. No TA/DA Fo Interview 
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Endoplasmic Reticulum (Structure and Function)

Endoplasmic Reticulum (Structure and Function).

Endoplasmic reticulum

Endoplasmic reticulum

 It is a network of channels present throughout the cell most of these channels are continuous with the plasma membrane toward the outer side on their inner side.
They are in contact with the nuclear membrane.
 The entire system of channel is called endoplasmic reticulum.

 Morphologically  Endoplasmic reticulum occurs in three forms.

1. Cisternae:
 The channels of Endoplasmic Reticulum are composed of spherical or tubular membranes are called cisternae. (pancreas, notochord,brain).

 2. Vesicles
the vesicle are oval membrane-bounded vascular structure having the diameter of 25 to 500 micrometre.

 3.Tubules
The tubules are branched structure forming the reticular system along with the cisternae and vesicle.

Types of Endoplasmic Reticulum:

 There are two types 
1. Granular or rough endoplasmic reticulum.
  
Ribosomes are attached with the Rough Endoplasmic reticulum. Rough endoplasmic reticulum founds abundantly in those which are active in protein synthesis.
Such as pancreatic cell, plasma cell, Goblet cell and liver cells.

2. Agranular or smooth endoplasmic reticulum.

 These are without ribosomes.
The smooth endoplasmic reticulum occurs mostly in those cells which are involved in the metabolism of lipids (including steroids) and glycogen.
 The smooth endoplasmic reticulum is generally found in interstitial cells, glycogen storage cell of the liver, conduction fibres of heart, spermatocytes and leukocytes.
 The muscle cells are also rich with smooth type of Endoplasmic Reticulum and here they are known as sarcoplasmic reticulum.

 Function of Endoplasmic Reticulum


1. Endoplasmic reticulum provides mechanical support to the cell.
2. The SER  is also involved in the metabolism of lipids.
3. The smooth endoplasmic reticulum detoxifies the harmful drugs and toxic material.
 4. The smooth endoplasmic reticulum converts the cholesterol of skin into Vitamin D.
 5. Smooth endoplasmic reticulum has enzyme for glycogen breakdown.
6. The rough endoplasmic reticulum is involved in the synthesis of protein.
7. some compounds like proteins are stored temporary in the endoplasmic reticulum.
8. In some cells smooth endoplasmic reticulum is responsible for transmission of impulse ( muscle cell and nerve cell). 

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