describe the elongation phase of translation.

Solutions

Expert Solution

Elongation phase of translation in prokaryotes: It includes codon to codon translocation of active ribosomes on mRNA in 5'-3' direction and forms peptide bond between codon specified amino acid. There are three elongation factors namely:

EF-Tu: Transport charged tRNA from cytosol to the A site of the ribosome in GTP bound state.
EF-Ts: Act as guanine nucleotide exchange factor and regenerates EF-Tu.
EF-G: Mediate translocation of active ribosome from one codon to next codon (GTP dependent process).

Elongation includes three sub-steps:

Binding of aminoacyl tRNA (charged tRNA) to the A site of ribosomes: Binding of charged tRNA is catalysed by GTP bound EF-Tu. Once tRNA properly binds to the A site, EF-Tu release with GTP hydrolysis and generation of active EF-Tu is catalysed by EF-Ts by replacing GDP from GTP.
Peptide bond formation: After the release of EF-Tu amino group of A site amino acid act as nucleophile on carboxylic group of P site amino acid and makes peptide bond. After peptide bond formation P site tRNA becomes uncharged and A site tRNA generates dipeptidyl tRNA.
Translocation of ribosomes: After peptide bond formation ribosome translocate to next codon. Translocation shifts dipeptidyl tRNA from A site to P site and uncharged tRNA from P site to E site and A site occupy next codon thus open for incoming amino acyl tRNA (charged tRNA). Translocation reaction catalysed by ribosomes itself (without EF-G) but EF-G maintain translocation efficiency during translation.

Elongation phase of translation in eukaryotes: The mechanism is same as that of prokaryotes described above only the elongation factors changes, there are mainly three elongation factors in eukaryotes:

eEF-1 : Transport charged tRNA (aminoacyl tRNA) from cytoplasm to the A site of ribosomes and is a GTP dependent process.
eEF-1 : Regenerate eEF-1
eEF-2: Translocate ribosome codon to codon (GTP dependent process)

gladiator answered 1 year ago

Next > < Previous

Related Solutions

Describe the process occurring at each feature during the elongation phase of translation can u tell...

Describe the process occurring at each feature during the elongation phase of translation can u tell me please ans its a 10 marks question

What is the order/describe the steps of the translation elongation microcycle

Describe what happens at each stage of translation (initiation, elongation, termination).

4. Illustrate the elongation phase of translation where the tRNA is in the site of the ribosome and is bound to codon number 5

4. Illustrate the elongation phase of translation where the tRNA is in the site of the ribosome and is bound to codon number 5. Label the sand 3 ends of all RNA's and label the S'UTR, 3'UTR, the Shine-Dalgamo (Kozac) sequence, and the translational start and stop codons on the template mRNA. Be sure to include the growing peptide chain and the large and small ribosomal subunits. Label each of the three ribosome sites. 5. What is the role of tRNA...

1. Describe translational elongation in 3 basic steps. 2. Describe the termination of translation in 3...

1. Describe translational elongation in 3 basic steps. 2. Describe the termination of translation in 3 basic steps

Both transcription and translation have Initiation, Elongation, and Termination phases. LIST and BRIEFLY DESCRIBE the major...

Both transcription and translation have Initiation, Elongation, and Termination phases. LIST and BRIEFLY DESCRIBE the major features of each (4 pts each). You may use prokaryotic or eukaryotic transcription. Transcription Initiation: Transcription Elongation: Transcription Termination: Translation Initiation: Translation Elongation: Translation Termination:

Which of the following is NOT directly associated with translation? A) Elongation of the polypeptide B)...

Which of the following is NOT directly associated with translation? A) Elongation of the polypeptide B) Formation of peptide bonds C) Complementary base pairing between codon and anticodon D) mRNA synthesis at the ribosome E) Transfer of amino acids by tRNAs

Actinomycin A is a drug that prevents successful translation by inhibiting elongation. The most likely direct...

Actinomycin A is a drug that prevents successful translation by inhibiting elongation. The most likely direct effect of this drug is to prevent the: a. Binding of the large ribosomal subunit to the small subunit b. breaking of the bond between tRNA and its amino acid c. disassociation of the ribosomal subunits d. start codon from binding e. formation of peptide bonds between two tRNAs

RNA processing Elongation Termination Transcription Initiation of translation Amino acid attachment

Decide which sequence of events is most CORRECT for the initiation and elongation steps of translation...

Decide which sequence of events is most CORRECT for the initiation and elongation steps of translation in prokaryotic cells? (1) small ribosomal subunit binds to mRNA (2) initiator tRNA binds start codon on mRNA (3) active 70S ribosome is formed (4) translocation of ribosome (5) binding of second aminoacyl tRNA A. 2, 3, 1, 5, 4 B. 1, 2, 3, 5, 4 C. 2, 1, 3, 4, 5 D. 1, 2, 3, 4, 5 E. 1, 3, 2, 4, 5

Subjects