LIFESCI 3 Chapter Notes - Chapter 17.1: Pseudouridine, Transfer Rna, Peptide
Document Summary
17. 1 deciphering the genetic code: trna as adaptor. Combinations of 3 nucleotides yield (43) 64 possible codons. Codon: combination of three nucleotides that specifies an amino acid. Transfer rna: covalently attaches to amino acids in a reaction require atp. Rna-amino acid hybrids could base-pair with mrna. Adaptor molecule that translates mrna sequence into polypeptides. Aminoacylated at the 3" terminus in an atp-dependent rxn trna + amino acid = aminoacyl-trna trna is charged with the amino acid. Amino acid specificity of trnas is provided by the enzymes that attach amino acids to. All trnas have a similar structure trnas form intramolecular base pairs and fold into a precise 3d structure. Trinucleotide sequence cca at the 3" terminus. 3" terminal a residue attaches to amino acid. Longer trnas have a short fifth arm trna folds up into a twisted l shape. Two arms of dna are critical for adaptor function. Located at the two ends of the l shape.
