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

Explain coarctation of aorta, Explain Coarctation of Aorta ? Coarctati...

Explain Coarctation of Aorta ? Coarctation of aorta may be isolated or it may have other co-existing cardiac and vascular lesions. In critically ill neonates with coarctation,

What do you mean by endemic goiter, Q. What is a goiter? What is endemic go...

Q. What is a goiter? What is endemic goiter? How this problem is socially solved? Goiter is the abnormal enlargement of the thyroid gland the goiter appears as a tumor in the a

Silver point extended below canal orifice-endodontics, Silver point extende...

Silver point extended below canal orifice: - This discrepancy between the round silver wire and an irregularly shaped canal provides the clinician with an opportunity to use so

Brodmann areas, One way that the cortex has been parcellated is based on fi...

One way that the cortex has been parcellated is based on fine-grained anatomical differences in the composition of the cortical layers: their thickness and types of neurons that ar

Identical twins, Identical Twins Human twins may be similar, when they...

Identical Twins Human twins may be similar, when they are formed from one egg (monozygotic) or fraternal while they are the result of fertilization of two different ova releas

Diagnosis of diabetes mellitus, Q. Diagnosis of diabetes mellitus? Time...

Q. Diagnosis of diabetes mellitus? Timely and proper diagnosis plays a key role not only in identifying new cases but also in managing old cases with or without diabetic compli

Describe ts murmur and their characterstic, Describe TS Murmur and their ch...

Describe TS Murmur and their characterstic ? Characteristic: It is a rumbling, and diastolic murmur heard at left lower sterna border that increases with inspiration. An OS may

Explain benefits of protein, Explain benefits of Protein Protein: Once ...

Explain benefits of Protein Protein: Once the energy requirements have  been estimated, protein requirements can be addressed. The aim is to achieve nitrogen balance. There are

Transport of substances done across the bryophyte tissues, Q. How is the tr...

Q. How is the transport of substances done across the bryophyte tissues? How is this feature related to the general size of these plants? In bryophytes there are no nutrient-co

Excretion in non-chordates, Excretion in Non-Chordates Excretion as de...

Excretion in Non-Chordates Excretion as described under Introduction of this unit refers to removal of the waste products of metabolism - carbon dioxide (CO 2 ) and water rele

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