1. Translation Section 11-2 cont.

2. Transcription

3. Translation 20 different amino acids 20 different amino acids A group of three nucleotides in mRNA code for one amino acid. This is called a codon. A group of three nucleotides in mRNA code for one amino acid. This is called a codon. AUG – start codon AUG – start codon UAA – Stop codon UAA – Stop codon Converts mRNA to Protein Converts mRNA to Protein Occurs at the ribosome in the cytoplasm Occurs at the ribosome in the cytoplasm

4. 1. When the strands of mRNA arrive in the cytoplasm, ribosomes attach to them. 2. Each tRNA molecule attaches to only one type of amino acid. The tRNA brings the amino acid to the ribosome.

5. 3. On the opposite side of the tRNA molecule from the amino acid site, there is a sequence of 3 nucleotides that are complement of the nucleotides in the codon.

6. 4. First codon is AUG (the start codon). The ribosome then slides along the mRNA to the next codon. 5. A new tRNA molecule carrying an amino acid pairs with the second mRNA codon.

7. 6. The first and second amino acid are jointed together by a peptide bond. 7. The process continues, forming a chain of amino acids until the ribosome reach a stop codon.

8. Translation