Ribosomes, Biology

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.

Posted Date: 10/4/2012 1:47:16 AM | Location : United States







Related Discussions:- Ribosomes, Assignment Help, Ask Question on Ribosomes, Get Answer, Expert's Help, Ribosomes Discussions

Write discussion on Ribosomes
Your posts are moderated
Related Questions
Explain some Do's and Don'ts when working in Laboratory? 1) Always wear a lab coat when working a laboratory. 2) Ensure that no harm is caused to yourself or the people work

Chromium Chromium functions as a component of the glucose tolerance factor, which serves to potentiate the action of insulin. Adding low concentrations (0.02 to 1.0 mg/kg) of c

Explain the Work of John Ray in Animal Taxonomy? The first important work on both animal and plants was initiated by John Ray (1627-1705). He followed Aristotle and divided ani

Bone Density The compact bone surrounding dense evenly spaced trabeculae with small cancellous spaces is ideal/suitable for implant placement. Dense or porous cortical bone is

Define Proteins in the immune system? Proteins such as γ-globulin serve to protect the body against foreign cells. The immunoglobulin produced by lymphocytes is the large polyp

I have a six page assignment, which involves barely any writing, just labeling some plant structures etc. Can someone do this?

Define the Buffer capacity - Nutritional Biochemistry? Buffer capacity can be defined as, 'the capacity of a solution to resist changes in pH on the addition of strong acid or

What are the affinities of pteridophytes with gymnosperms?

When lipid is added to a solution of a detergent in water, the detergent breaks up large globules of the lipid into much smaller globules. What effect do you think a detergent woul

Explain about G-protein   A.  When an agonist binds to the binding site of a G-protein-coupled receptor (GPCR), this leads to GTP displacing a GDP bound to the alpha subunit of