1/18/2016 Translation Elongation Translation Termination Termination codons-UAA. UAG.and UGA-are codons The first tRNA is released for which there are no corresponding tRNA. The second amino acid Thus,ribosome stops when it reaches a stop codon The ribosome continues The polypeptide is released to move along the mRNA The last tRNA is released New amino acids are ·Ribosome comes apart added to the polypeptide The polypeptide forms a protein Speeding Up Protein Assembly in Bacteria Finishing Touches To be active,a protein requires folding into its final 3D Translation of mRNA can structure As the peptide chain is released from the ribosome,it begins folding to achieve its biologically active tertiary mRNA is completed conformation Transcription and Other alterations c alled post-translational modifications translation occur acters may be add ly in bacteria form quaternary leve einsjoin Polyribosomal complex allows for the synthesis of many protein molecules simultar om the 111/18/2016 11 • The first tRNA is released Translation Elongation • The second amino acid joins the third by another peptide bond. • The ribosome continues to move along the mRNA. • New amino acids are added to the polypeptide • Termination codons – UAA, UAG, and UGA – are codons for which there are no Translation Termination corresponding tRNA. • Thus, ribosome stops when it reaches a stop codon • The polypeptide is released • The last tRNA is released • Ribosome comes apart • The polypeptide forms a protein • Translation of mRNA can begin before the transcription of the Speeding Up Protein Assembly in Bacteria mRNA is completed • Transcription and translation occur simultaneously in bacteria due to lack of a nucleus • Polyribosomal complex allows for the synthesis of many protein molecules simultaneously from the same mRNA molecule. • To be active, a protein requires folding into its final 3D structure • As the peptide chain is released from the ribosome, it begins folding to achieve its biologically active tertiary Finishing Touches g g gy y conformation • Other alterations called post-translational modifications may be required. Cofacters may be added or proteins join with other proteins to form quaternary levels of structures