translation

• Translation is the process by which ribosomes read an mRNA molecule to produce a protein.
• During translation, tRNAs bring specific amino acids to the growing polypeptide chain at the correct locations specified by the codons on the mRNA.
• The genetic code consists of three-letter sequences called codons, with each codon specifying one amino acid or a stop or start signal.
• Most amino acids have more than one codon that codes for them.
• RNA polymerase moves along the template strand in the 3' to 5' direction
• the mRNA will contain uracil instead of thymine
• In translation, mRNA molecule attaches to a ribosome
• tRNA molecules have a triplet of unpaired bases at one end, this is the anticodon and a region where a specific amino acid can attach at the other
• There are about 20 different tRNA molecules, each with a specific anticodon and specific amino acid binding site

  The tRNA molecules bind with their specific amino acids and bring them to the mRNA molecule on the ribosome
• the anticodon on each tRNA molecule pairs with a complementary codon on the mRNA molecule
• Two tRNA molecules fit onto the ribosome at one time, one carrying each amino acid
• A peptide bond is formed (via a condensation reaction) between the two amino acids
• This process continues until a ‘stop’ codon on the mRNA molecule is reached
• The amino acid chain then forms the final polypeptide