BIOCHEM 3G03 Chapter 22: Chapter 22 Protein Synthesis

• School: McMaster University
• Department: Biochemistry
• Course: BIOCHEM 3G03
• Professor: Daniel Yang

Document Summary

Translation (cid:396)e(cid:395)ui(cid:396)ed (cid:862)adapto(cid:396)(cid:863) (cid:373)ole(cid:272)ules (cid:894)trna(cid:895) that (cid:272)a(cid:396)(cid:396)ied a(cid:374) a(cid:373)i(cid:374)o a(cid:272)id a(cid:374)d (cid:396)e(cid:272)og(cid:374)ized genetic information in the form of a sequence of nucleotides. Mutation resulting from deletion of a nucleotide can be correct by a second mutation inserting another nucleotide into the gene corrects the reading frame: given nucleotide sequence in mrna can potentially have 3 different reading frames. Genetic code is degenerate several mrna codons may respond to the same amino acid: only met and trp have one codon also occur the least frequently. Met (aug) = start codon; uaa, uag, uga = stop/nonsense codons. Bacteria ~ 30-40 different trnas; mammalian cell ~150 redundancy. Iso-acceptor trnas: trnas that bear the same amino acid but have different anticodons. Structure of all trnas are similar: ~76 nucleotides (54-100 range); are post-transcriptionally modified, many bases pair intramolecularly creating a cloverleaf secondary structure. Eg(cid:373)e(cid:374)t at 5" pai(cid:396)s (cid:449)ith (cid:271)ases (cid:374)ea(cid:396) (cid:1007)" acceptor stem. D loop contains modified base dihydrouridine.