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

Set up a potometer in the laboratory, A student set up a potometer in the l...

A student set up a potometer in the laboratory and measured the rate of movement of water in the capillary. An average of four readings gave a rate of 50mm per minute. The apparatu

Explain the major classes of lipids, Explain the major classes of lipids ...

Explain the major classes of lipids The major classes of lipids are simple lipids (acylglycerols and waxes); Compound lipids (glycerophospholipids); Derived lipids (compounds t

Glands associated with eyes, GLANDS - 1 .       LACRYMAL GLANDS - ...

GLANDS - 1 .       LACRYMAL GLANDS - Tear glands numbers are 3. Its secretion is aquous & salty, keeps eye ball wet, give nourishment to cornea. Lysozyme also present

Renal failure and transplantation, KIDNE Y (RENAL FAILURE) - RF - Part...

KIDNE Y (RENAL FAILURE) - RF - Partial or total inability of kidney to carry excretory functions is called RF. It leads to uremia (excess of urea in blood), salt-water imba

Islet of langerhans, Islet of Langerhans: They are insulin-producing tissue...

Islet of Langerhans: They are insulin-producing tissues. It was discovered by Paul Langerhans in 1869. These cells are in groups and look like islands in the pancreas. There are ab

Advantages and disadvantages of mechanical valves, Advantages Durab...

Advantages Durability of these vales are long lasting.  Disadvantages Need for anticoagulant therapy is life long.  Risk of thrombo-embolism is hi

Define standardization - nutritional biochemistry, Define Standardization ...

Define Standardization - Nutritional  Biochemistry? One of the substances involved in a titration must be used as a standard for which the amount of substance present is accura

Explain the the system of the nomenclature, Explain the The system of the n...

Explain the The system of the nomenclature The system of the nomenclature and the classification of enzymes is based exclusively on the reaction that is catalyzed and does not

What do you mean by blinking and peering in the eyelid, What do you mean by...

What do you mean by blinking and peering in the eyelid? Blinking and Peering: Blinking considers as to the opening and closing movements of the eyelid. The function of b

An experiment to determine which seed is best for lawn, Assume that your ya...

Assume that your yard has many tall trees that result in about fifty percent of the yard being shaded and fifty percent of the yard being exposed to full sun. The shaded areas and

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