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Translation

Translation

Description:

This lesson will explore the three stages of translation that culminate with the production of a polypeptide chain.

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Tutorial

What's Covered

This lesson is going to look at translation as the second step in protein synthesis by covering:

  • Initiation
  • Elongation and Termination

1. Initiation

In translation , instructions from a single stranded mRNA, which was formed from transcription, are translated into proteins. This occurs in the cytoplasm of the cell and there are three stages to translation:

  • Initiation
  • Elongation
  • Termination.

Term to Know

  • Translation
  • The process of “reading” a strand of mRNA and translating its message into a protein. This occurs in ribosomes and consists of mRNA and tRNA interacting with one another.

The first step is initiation. During initiation, the small and large ribosomal subunits will join together and then initiator tRNA will arrive at the start codon on mRNA. The start codon marks the beginning of a new polypeptide chain, and codons are groups of three nucleotides that code for amino acids. Then after this amino acids can be added.

Term to Know

  • Initiation
  • The beginning of translation, initiation occurs by the assembly of the ribosomal subunits and when tRNA interacts with the start codon on mRNA
The tRNA carries an anticodon, and these will match up with the strand of mRNA using the base pair rules. The tRNA also carries an amino acid.


The same thing will happen with this next codon, or group of three nucleotides. The next codon and anticodon will match, which signal for a certain amino acid. These amino acids will start building up in this chain called a polypeptide chain.

Term to Know

  • Polypeptide Chain
  • The primary structure of a protein, a polypeptide chain is a linear chain of amino acids that are covalently bound by peptide bonds.


2. Elongation and Termination

The newly formed polypeptide chains build proteins. These amino acids are held together by a peptide bond. This stage is where those amino acids are being built into a growing polypeptide chain through a process called elongation.

Termination being the last stage of translation, is when the stop codon of mRNA signals the end of translation. With that, the polypeptide chain is complete.

Term to Know

  • Elongation
  • When the appropriate anticodon of tRNA interacts with its codon counterpart on mRNA during translation. Elongation is the second step of translation and will continue until the stop codon is reached.
  • Termination
  • When the stop codon is reached during translation, translation ends and the polypeptide chain is released.

Summary

Initiation is the first stage in translation. Here the ribosomal units come together and then tRNA will arrive at the start codon of mRNA. The anticodons on the tRNA will match up with the codons on the mRNA. They will signal for certain amino acids, which then begin to build up and form a polypeptide chain. follow. Elongation occurs as the chain gets longer, and termination occurs when stop codon of the mRNA signals the end of translation.

Source: This work is adapted from Sophia Author Amanda Soderlind

TERMS TO KNOW
  • Translation

    The process of “reading” a strand of mRNA and translating its message into a protein. This occurs in ribosomes and consists of mRNA and tRNA interacting with one another.

  • Initiation

    The beginning of translation, initiation occurs by the assembly of the ribosomal subunits and when tRNA interacts with the start codon on mRNA.

  • Elongation

    When the appropriate anticodon of tRNA interacts with its codon counterpart on mRNA during translation. Elongation is the second step of translation and will continue until the stop codon is reached.

  • Termination

    When the stop codon is reached during translation, translation ends and the polypeptide chain is released.

  • Polypeptide Chain

    The primary structure of a protein, a polypeptide chain is a linear chain of amino acids that are covalently bound by peptide bonds.