Endoplasmic reticulum, Biology

ENDOPLASMIC RETICULUM (ER)

Eucaryotic celIs have two major compartments- nucleus and cytoplasm. Cytoplasm was known to have no structure until the discovery of electron micrsscope. That cytoplasm is permeated by a membranous network called endoplasmic reticulum (ER), was revealed only after the introduction of electron microscope. Endoplasmic reticulum is a three dimensional network of membrane channels which constitutes more than half of the total membrane of the cell, ER is a highly folded and convoluted structure and forms a single continuous sheet enclosing one continuous sac. The interior of the sac is called "cisternal space" or "ER lumen". This is separated from the cytoplasm also called cytosol by a single membrane which mediates the communication between these two compartments. ER provides the cell with a compartment for storage of substances to be kept separate from cytosol. In addition, it has a key role in the biosynthesis of macromolecules.

ER is a double membranous organelle which consists of interconnecting flattened sacs called cisternae or interconnected tubules or vesicles. Cisternae are temporary storage sites for nutrients (Figure shown below).

 

527_endoplasmic teticulum.jpg

Posted Date: 12/10/2012 1:43:51 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
Question : (i) What is Ciguatera Fish Poisoning provide some examples of fishes implicated in Ciguatera Fish Poisoning in Mauritius? (ii) Provide a general account of its d

what the importance of phylla protozoa

Age-Sex Distribution While studying exponential growth we need to know more than just the birth and death rates because these rates vary with age and sex. Age structure in a

Classification of zoonoses More than 300 zoonoses of diverse etiologies are recognized. Thus, a very large number of zoonoses call for classification, especially for teaching

Define Derived proteins -  Primary Protein Derivatives? Derived proteins are the derivatives of the protein molecule, apparently fonned through hydrolytic changes in the molecu

Water Water usually forms about 50% to90% part of living protoplasm. Life upon earth originated in the ocean and the conditions of that aqueous primeval environment have been r

Properties and Functions of Synapses There is an interval between depolarisation of the presynaptic terminal and the earliest appearance of a postsynaptic response. This inter

Organic Substances - Abiotic Components These include carbohydrates, proteins, lipids and their derivatives which are derived from the waste products of plants and animals or

Q. Explain Degradation of Fats? Fats are the esters of glycerol and fatty acids and are called as 'glycerides'. Fats are susceptable to hydrolysis, oxidation and other che

Define the Sources of Vitamin E? Vitamin E is present in almost all foodstuffs. It is found in wheat germ, corn, nuts, seeds, olives, spinach, asparagus and other green leafy v