Question

what is tRNA

Answer 1

tRNA is involved in the translation of the nucleic acid message into the amino acids of proteins. tRNA itself is an RNA molecule with a conserved inverted L structure. One end of the tRNA contains an anticodon loop which pairs with a mRNA specifying a certain amino acid. The other end of the tRNA has the amino acid attached to the 3' OH group via an ester linkage.

tRNA with an attached amino acid is said to be "charged". The enzyme that attaches the amino acid to the 3'-OH is called an aminoacyl tRNA synthetase (aaRS). There is a specific tRNA for each amino acid, 20 in all. Similarly, there is a specific aaRS for each tRNA.

Only the first 2 nucleotides in the tRNA anticodon loop are strictly required for the decoding of the mRNA codon into an amino acid. The third nucleotide in the anticodon is less stringent in its base-pairing to the codon, and is referred to as the "wobble" base. Since the genetic code is degenerate, meaning that more than one codon can specify a single amino acid, the anticodon of tRNA can pair with more than one mRNA codon and still be specific for a single amino acid.

Answer 2

you can also refer to the following sites...............
http://en.wikipedia.org/wiki/Transfer_RNA
http://www.cs.stedwards.edu/chem/Chemistry/CHEM43/CHEM43/tRNA/Function.htm