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

Why is sub-culturing essential in plant tissue culture, Why is sub-culturin...

Why is sub-culturing essential in plant tissue culture? Explain the process of heterosis. How is it dissimilar from inbreeding depression? Where and how is urea produced in

Nervous system control of blood pressure, Q. Nervous System control of bloo...

Q. Nervous System control of blood pressure? Most nervous controls are achieved via involuntary reflex arcs involving pressoreceptors, the vasomotor centers of the medulla, and

Saturated fatty acids, Saturated Fatty Acids - These are solid at ro...

Saturated Fatty Acids - These are solid at room temperature. These are metabolically less active so have a tendency to deposit in the body (synthesized in body) These

Physiological adaptation of parasites for infectioness, physiological adapt...

physiological adaptation of parasites for infectiousness?

What is central shunt in palliative operations, What is Central Shunt in Pa...

What is Central Shunt in Palliative Operations? When the pulmonary artery branches are small, an interposition graft could be used as a shunt between main pulmonary artery and

Circulatory system, Circulatory system, closed is a system which uses a co...

Circulatory system, closed is a system which uses a continuous series of the vessels of different sizes to deliver blood to body cells and return it back to the heart; it is found

Are alleles segregate during meosis, Gregor mendel was an austrain augustia...

Gregor mendel was an austrain augustianian monk; his work most notably showed that. a. Alleles segregate during meosis b. Capital alleles are dominant c. The genetic material is pa

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