2. PROTEIN SYNTHESIS PRESENTATION Adenine Uracil Guanine Cytosine

3. There are two processes involved: Transcription- Copying of DNA code to form mRNA. Translation- Conversion of RNA code into a sequence of amino acids.

4. RNA POLYMERASE DNA DOUBLE HELIX Transcription-RNA polymerase binds to double helix at promoter region

5. Sense strand Anti-sense strand Bonds between bases are broken and DNA double helix unwinds

6. Sense strand Anti-sense strand Free nucleotides from inside nucleus bind onto exposed DNA bases forming a molecule of mRNA Free Nucleotides

7. + DNA double helix rewinds mRNA When mRNA has formed, it moves away and the DNA reforms

8. mRNA 5` end 3` end Guanine “CAP” Poly-A The 5` end of the polynucleotide mRNA is modified by a guanine cap which is thought to be a translation promoter. About 100 adenines (POLY A) are added to the 3` end which is thought to: >to be a signal for the exit of mRNA from the nucleus. >Protect mRNA from enzyme action.

9. Anti Codon bases tRNA Amino acid Translation- Diagram of an anti-codon

10. 2 Codons mRNA Ribosome 5` end 3` end Anti Codon. 2 codons enter the information processing region of ribosome. An anti-codon attaches to the bottom of ribosome and codes the amino acid with corresponding bases.

11. mRNA Ribosome 5` end 3` end Anti Codon. A second anti-codon comes along and after it has coded its amino acid, a peptide bond is formed between the 2 amino acids Peptide bond

12. 5` end 3` end Peptide bond 2nd and 3rd codons The first anti-codon detaches leaving its amino acid behind. The mRNA moves along ribosome and a third tRNA binds onto the third codon.

13. The End By Sahira, Kulsoom and Sarah.