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Dictionary » R » Ribosome RibosomeDefinition 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.
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.
Related forms: ribosomal (adjective).
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Results from our forumRe: 'Evolution'-the most retarded myth ever.... yet you are advocating a Jewish old earth creationist book by Lee Spetner? We see then that the mutation reduces the specificity of the ribosome protein and that means a loss of genetic information. ... Rather than saying the bacterium gained resistance to the antibiotic, it is more ...
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Re: 'Evolution'-the most retarded myth ever.... my goodness, they will have HELL to pay. http://en.wikipedia.org/wiki/Lee_Spetner We see then that the mutation reduces the specificity of the ribosome protein and that means a loss of genetic information. ... Rather than saying the bacterium gained resistance to the antibiotic, it is more ...
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'Evolution'-the most retarded myth ever.... my goodness, they will have HELL to pay. http://en.wikipedia.org/wiki/Lee_Spetner We see then that the mutation reduces the specificity of the ribosome protein and that means a loss of genetic information. ... Rather than saying the bacterium gained resistance to the antibiotic, it is more ...
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Re: Theories - Origin of Life... natural occurring mobile genetic elements in tetracyclines that produces the resistance. I also went on to state Even if a mutation occurs in the ribosome that may provide an advantage to the bacterium, it would come at a cost. Ribosomal mutations, while providing antibiotic resistance for the ...
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Re: question for evolutionary biologist.... NASA has discounted it. One of the latest studies published in March this year can be found here:- http://news.illinois.edu/news/12/0312ribosome_GustavoCaetano-Anolles.html Study of ribosome evolution challenges RNA world hypothesis Here is what the lead researcher had to say “This is ...
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