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Post by IanMalcolm on Jun 26, 2004 5:14:35 GMT -5
Every educated person knows that DNA is an abbreviation for Deoxyribonucleic Acid. But what I dont know is what RNA and mRNA is (mRNA means messanger RNA). I would also like to know what tRNA and RNAi stands for...
Any help would be nice, thanks.
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Post by IanMalcolm on Jun 26, 2004 21:50:49 GMT -5
Pretty much, RNA is ribonucleac acid. and its in a single strand not the duble helix of DNA and is found mostly in cytoplasm. m-RNA carries transcribed genetic code from the DNA in the nucleus of a cell to the ribosomes at the protien building site. t-RNA or transfer RNA selects and transfers the amino acids required for protien synthesis. S-RNA is another name for t-RNA. tRNA is Transfer RNA. tRNA and mRNA both aid in protein synthesis I believe, they help with the duplication of DNA...
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Post by IanMalcolm on Jun 26, 2004 22:17:51 GMT -5
RNA - Ribonucleic acid.
DNA - deoxyRibonucleic acid.
The difference is that the nucleic acid is made of a base (A, T, C or G for DNA; A, U, C or G for RNA) attached to a sugar and phosphate backbone. The sugar in RNA is Ribose, the sugar in DNA is deoxyRibose, which is Ribose with one Oxygen atom missing (hence "Deoxy"Ribose).
mRNA is a "photocopy" of a specific gene. When a gene is switched "On" the specific DNA in the genome is copied into messenger RNA. The messenger RNA is then fed into a large collection of proteins and RNA molecules called the "Ribosome" (these structural RNA molecules are known as Ribosomal RNAs or rRNA).
The Ribosome translates the code, three bases at time (three bases is known as a triplet "Codon"). Depending on the sequence of As, Us, Cs or Gs in the codon, the ribosome attaches one of the 20 amino acids that make up proteins. Three codon sequences also code for a STOP, which is a marker for the end of the protein.
tRNA is transfer RNA - a short stretch of RNA that folds into a clove-leaf like shape. One end attaches to a specific amino-acid, and there are specific tRNA molecules for each of the 20 amino acids. The other end of the tRNA binds to the codon which is currently being processed by the ribosome. In this way the correct amino acid is presented to the ribosome.
As the ribosome works its way along the messenger RNA, more and more amino acids are joined together in a long chain. This long chain then folds into the correct shape for the mature protein.
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Post by Azmodan on Jun 28, 2004 11:21:25 GMT -5
Duh...... brain hurts
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