Ribosomes, Biology

Assignment Help:

Ribosomes:     are minute nonmembranous  and dense spheroidal particles or  granules. First observed by   electron   microscopy by palade 1955. Being only about 200 to 250 a in diameter these are smallest, but most abundant of all cytoplasmic organelles. Every cell contains several thousands to millions of ribosomes. Most  of these  are linked  at the surface of endoplasmic reticulum  many  are free  in   the cytosol, and some  are found in the   in the nucleus and mitochondria  also  in  chloroplasts  of plant cells.

Structurally. Each ribosome has two parts a proximal larger subunit linked to the endoplasmic are composed of RNA and proteins approximately in equal amounts. The ribosomal RNA  ( rRNA)   has only four macromolecules .  Three in the larger subunit  and one the  smaller subnuits.   Considerable portion of these RNA molecules secondarily become  double stranded due to intermolecular the intermolecular base  pairing  so that  the molecules become 3 dimensional .The ribosomal protein   include 73 macromolecules 40 in  large in 33 in small subunits .

Ribosomal  subunits  are assembled from  their  component  r RNA  and protein  molecules  in the nucleolus of nucleus. These  are of the four r RNA  molecules are  synthesized  in the nucleolus . The   fourth is   synthesized by some chromosome outside the nucleolus. This and the 73 protein molecules synthesized in the cytoplasm migrate to the nucleolus for being incorporated in ribosomal subunits. The latter diffuse out into the cytoplasm and assemble to form ribosome's most of which link the endoplasmic reticulum.


Related Discussions:- Ribosomes

What is recombination frequency?, What is recombination frequency? The ...

What is recombination frequency? The Recombination frequency, or crossing over rate, is the percentage of recombinant gametes made by crossing over (in relation to the number o

Netlike membranous complex of superposed flat saccules, Q. A netlike membra...

Q. A netlike membranous complex of superposed flat saccules with vesicles detaching from the extremities seen in electronic microscopy. What is the observed structure? What is its

Beta decay, Beta decay  is the type of radioactive decay in which the radio...

Beta decay  is the type of radioactive decay in which the radioisotope emits a little negatively-charged and fast-moving particle from its nucleus. A beta particle is almost simila

What is phylum porifera in classification of the animal king, What is Phylu...

What is Phylum Porifera in Classification of the Animal King? Sponges are the simplest form of animals. Their bodies are not organized in any specific pattern other than masses

Explain process of selection of taxonomic characters, Explain process of Se...

Explain process of Selection of taxonomic characters Selection of taxonomic characters Eventually classification systems may be based almost entirely on direct study of th

What is the treatment for hiv, Anti-retroviral drugs are given to the patie...

Anti-retroviral drugs are given to the patient. They lesser the viral load and gives relief from infection, but it is not lasting it is temporary relief i.e. it cannot cure.

Chemical stress - atmospheric imbalances, Chemical Stress - Atmospheric imb...

Chemical Stress - Atmospheric imbalances At least two components of the environment, oxygen and carbon dioxide that plants require are predominantly in the gaseous form. As yo

One benefit of including vegetable fibre in the diet, State one benefit of ...

State one benefit of including vegetable fibre (roughage) in the diet   Vegetable fibre retains water (keeping the faeces soft and bulky), stops constipation, decreases the

Mechanism of regeneration, MECHANISM OF REGENERATION - T.H. morgan reco...

MECHANISM OF REGENERATION - T.H. morgan recognised 2 primary mechanisms - M o r ph o l axis Epim orphosis 1. Production of enti

Pathophysiology of constrictive pericarditis, Q. Pathophysiology of constri...

Q. Pathophysiology of constrictive pericarditis? Ans. The thickened and rigid pericardium causes constriction of the heart and restricts ventricular dialatation and diasto

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd