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Ribosome

Definition

noun, plural: ribosomes

(Science: cell biology)

(1) A minute particle composed of protein and ribonucleic acid (RNA) that serves as the site of protein synthesis.

(2) A molecule consisting of two subunits that fit together and work as one to build proteins according to the genetic sequence held within the messenger RNA (mRNA). Using the mRNA as a template, the ribosome traverses each codon, pairing it with the appropriate amino acid. This is done through interacting with transfer RNA (tRNA) containing a complementary anticodon on one end and the appropriate amino acid on the other.

(3) A sphere-shaped structure found in the cytoplasm of prokaryotic and eukaryotic cells. Some ribosomes occur freely in the cytosol whereas others are attached to the nuclear membrane or to the endoplasmic reticulum (ER) giving the latter a rough appearance, hence, the name rough ER or rER.


Supplement

Ribosomes of prokaryotes (e.g. bacteria) are smaller than most of the ribosomes of eukaryotes (e.g. plants and animals). However, the plastids and mitochondria in eukaryotes have smaller ribosomes similar to those in prokaryotes – a possible indication of the evolutionary origin of these organelles.

In mid-1950s, ribosomes were first observed as dense particles or granules by George Palade with his electron microscope. In 1958, the term ribosome was proposed by the scientist, Richard B. Roberts.


Word origin: from ribonucleic acid and Greek: soma, meaning body.

Related forms: ribosomal (adjective).
Related terms: ribosome binding site, ribosome-lamella complex.


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Results from our forum


Re: Any SOLID arguments against evolution?

... many amino acids are in the enzymes which transcribe the mRNA? 2. The RNA journey --Then the mRNA leaves the nucleus like a snake and meets with a ribosome. How many amino acids are in the ribosome? 3. Translation -- Then the mRNA and ribosome lock together like material going through a sewing ...

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by AFJ
Wed Jun 03, 2009 12:15 am
 
Forum: Evolution
Topic: Any SOLID arguments against evolution?
Replies: 100
Views: 1605

Re: Any SOLID arguments against evolution?

... League school, Brown University). Never have figured out how evolutionists can ignore probability. Hemoglobin is formed by the coded mRNA and the ribosome, with the tRNA molecules which bring the proper amino acids which will match the nuecleotides in the mRNA. But mRNA gets its instructions from ...

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by AFJ
Sat May 30, 2009 2:36 am
 
Forum: Evolution
Topic: Any SOLID arguments against evolution?
Replies: 100
Views: 1605

Retained Intron through Translation

... out in the maturation of an mRNA strand? All I could come up with was that you would get a garbage protein with incorrect amino acids once the ribosome got to the intron. I guess also if the intron length (in nucleotides) were a multiple of 3 you would just get an extra domain in the normal ...

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by cgh24
Tue May 05, 2009 9:55 pm
 
Forum: Genetics
Topic: Retained Intron through Translation
Replies: 1
Views: 121

tRNA and anti-sense

well transcription and translation are dynamic processes, the polymerase and the ribosome move on the nucleic acid strand in a certain direction. what direction (from where to where)?

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by MrMistery
Sun May 03, 2009 1:56 pm
 
Forum: Molecular Biology
Topic: tRNA and anti-sense
Replies: 3
Views: 194

Protein Synthesis Steps

... that might help. There are a few things I wish I could change. For instance, the mRNA should loop into a circle before the small subunit of the ribosome docks at the 5' cap. Overall though, this shows the steps of transcription, splicing, nuclear export and ribosomal assembly in cartoon form. ...

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by jonmoulton
Wed Apr 08, 2009 3:39 pm
 
Forum: Genetics
Topic: Protein Synthesis Steps
Replies: 3
Views: 507
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