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

Define regulation of water balance for the kidneys, Define Regulation of Wa...

Define Regulation of Water Balance For the kidneys? The kidneys are highly efficient conservators of body water. Although the kidneys filter 180 L of blood per day (125 ml / mi

Simple febrile convulsions, Simple Febrile Convulsions These are convu...

Simple Febrile Convulsions These are convulsions associated with fever and infection, and is commonest causes of seizures during infancy and early childhood. These convulsio

Mutualist exploration of cellulose digestion, Q. What is meant by "mutualis...

Q. What is meant by "mutualist exploration of cellulose digestion", a phenomenon that occurs in some mammals and insects? Herbivorous animals eat great amounts of cellulose a s

Difference between translation and transcription, Q. What is the difference...

Q. What is the difference between translation and transcription? Transcription is the name given to the formation of DNA molecules from an open DNA chain used as a template, Tr

Determine the working of law of diminishing return, Determine the working o...

Determine the working of Law of diminishing return According to the 'Law of diminishing return' the increase in the yield by a unit increase of the defi cient factor is proport

Accidents resulting in death, Accidents Resulting in Death Accidents t...

Accidents Resulting in Death Accidents that cause death are dealt with in a different way. The law requires full compensation to the widow for complete life or until remarriag

Bacteriophage, Bacteriophage is a virus which infects a bacterium and whic...

Bacteriophage is a virus which infects a bacterium and which is many times used in molecular genetics experiments as the vector, or cloning vehicle. Recombinant phages can be made

Middle piece - structure of the sperm, Middle piece - Structure of the Sper...

Middle piece - Structure of the Sperm Just behind the head, the small constriction (neck) carries a distal and a proximal centriole. The two lie at right angle to each other.

Natural versus artificial-man-made-environment, Natural versus Artificial (...

Natural versus Artificial (Man-made) Environment The environments discussed so far are, natural environments. In several instances man has greatly altered the natural condition

Xerophytes, Xerophytes Xerophytes are sometimes loosely defineri as 'pl...

Xerophytes Xerophytes are sometimes loosely defineri as 'plants of dry habitats'. But others have defined xerophytes as 'plants which grow on the substratum that usually beco

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