DNA Translation

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  • Created by: Leila
  • Created on: 04-06-11 15:54

Translation - is the assembly of polypeptides at ribosomes

Translation is the second stage of protein synthesis where amino acids are assembled into a polypeptide.

Each group of THREE bases on the mRNA molecule is called a codon. Each codon stands for a particular amino acid.
Some codons however code for STOP or START.
e.g. Methionine - START - AUG
                         - STOP - UAA

The sequence of amino acids is critical because :

- it forms the primary structure of a protein

- its primary structure determines it tertiary structure

- therefore it determines the FUNCTION of the protein

Transfer RNA (tRNA) is made in the nucleus and passes out to the cytoplasm. tRNA is folded up into a hairpin shape and has three exposed nucleotides at one end where an AMINO ACID will join. At the other end it will have an ANTICODON. The anticodon will join with its complementary CODON on the mRNA.

tRNA with a certain anitcodon can only bind with a certain amino acid.

How the Polypeptide is assembled

1.  A molecule of mRNA binds to a ribosome. Two codons along

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