Endoplasmic reticulum, Biology

ENDOPLASMIC RETICULUM

Bulk of the cytoplasmic  compartment of a cell is occupied by complex , continuous  channel  system  in the form a network  of closed membrane bound and  intercommunicating  branched tubules,  vesicles and flattened sacs ,This  system was  discovered by porter (1945)  and named endoplasmic  reticulum, by him in 1953. It is distinguished  into two part  rough or granular endoplasmic reticulum  and smooth  or agranular endoplasmic  reticulum ,At place  tubules  of the ER may be seen  connected  with plasma membrane and nuclear  envelope.

The wall of endoplasmic reticulum is a unit membrane  structurally resembling  the plasma  membrane .Its  outer surface faces the cytosol  and the  inner one faces the lumen of  the reticulum,  which  contains a  watery fluid , The  roughness of the RER is because  of numerous minute particles, called ribosomes, attached  to  its outer surface.

Functions of endoplasmic  reticulum:

1.  It provides  mechanical support  to the cytoplasm as  an accessory  to the cytoskeleton,

2.      It acts as a continuous intracellular  transport system  between   nucleus and  cytosol  and between  the cytosol and extracellular  medium, exchanging  materials with  the cyotosol by  osmosis, diffusion  and active transport .

3.      The RER collects  and stores, in the fluid of its cavity, the proteins synthesized  by its  surface  bound ribosomes. Many  of these proteins are first processed by Means of enzymes and , then transported to  the cytosol for use by  various  other organelles.

4.      The SER is rich in other  important metabolic  enzymes  which   bring  about  synthesis  of triglycerides for  storage such as in tissues, of phospholipids and   cholesterol in all cells for generating  new  units membrane  required for cell repair  growth  and division , and  of steroid  hormones inc certain endocrine glands.

5.       In liver cells, the SER is involved  insynthesis  of lipoproteins  carbohydrade  metabolism  synthesis  of glycogen , its  storage and its  subsequent breakdown   into  glucose .

6.       Its  vesicles reform the nuclear  membrane  at telophase stage   of cell  division , This membrane  dissolves at the earlier stages  of division .

7.      In  muscle cells. It serves   for  intracellular  conduction of impulses  and release and withdraw  of calcium ions.

8.      In lymphocytes , plasma  cells and liver cells etc.  SER is involved in  detoxification  of endogenous  and exogenous antigens.

Posted Date: 10/4/2012 1:38:38 AM | Location : United States







Related Discussions:- Endoplasmic reticulum, Assignment Help, Ask Question on Endoplasmic reticulum, Get Answer, Expert's Help, Endoplasmic reticulum Discussions

Write discussion on Endoplasmic reticulum
Your posts are moderated
Related Questions
mORPHOLOGY OF AMOEBA AND ITS ADAPTATIONS

Q. Evaluation of osseointegration? All the parameters of proper implant selection, atraumatic sequential osteotomy preparation and the attainment of primary stability are focus

Q. What do you mean by Binomial system in binomial nomenclature? In the previous sections we have outlined the concepts of binomial nomenclature at International level and the

Oseltamivir (Tamiflu)   This oral neuraminidase inhibitor, started within 36 hours of symptom onset, can decrease the severity and duration of symptoms caused by either influ

Define Metabolic Effects of Thyroid Hormones? Although (T 4 ) is quantitatively predominant, (T 3 ) is the more active form. The mechanism of action of thyroid hormones appears


Explain the Primary Treatment for Managing Food Allergies? The primary treatment for managing food allergies is eliminating the offending food or foods. In fact, non-pharmacolo

Mass transportation is the access or the exiting of substances in or from the cell engulfed by portions of membrane. The fusion of internal substance-having membranous vesicles wit

Q. Explain Pathology of aortic stenosis? Congenital abnormalities of aortic valve may lead to unicuspid aortic valve. This may be dome shaped with central stenotic orifice. Uni

Define Antioxidant Action of Polyphenols? The properties of Polyphenols due to which they have been identified to act as antioxidant is because they: - act as termi