1. DNA: Transcription & Translation How do we go from DNA to PROTEIN?

2. WHAT DO WE NEED? DNA RNA –mRNA: messenger RNA –rRNA: ribosomal RNA –tRNA: transfer RNA Amino Acids  Proteins

3. DNA The genetic code or “blue-print” of life Contains the bases A, T, C, and G to code for amino acids

4. DNA/ Genes/ Codons DNA is made of approximately 80,000 genes Genes are sections of DNA that code for a single protein Codons are a set of 3 bases that code for an amino acid

5. RNA Polymer of ribonucleotides –Sugar (ribose) –Phosphate group –Nitrogenous base (A, U, C, G) Single-strand Three types: mRNA, rRNA, tRNA

6. ROLES OF RNA mRNA: transports information from DNA from the nucleus to the cell’s cytoplasm rRNA: (makes up ribosomes): clamps on to mRNA and reads its information to assemble amino acids in the correct order tRNA: transports amino acids to the ribosomes to be assembled into proteins

7. Transcription & Translation

8. TRANSCRIPTION Process in the cell’s nucleus where enzymes make an RNA copy (mRNA) of the DNA strand

9. Steps of Transcription Separation of Strands: enzymes unzip DNA in the bases Base Pairing: free RNA ribonucleotides pair with complementary DNA bases –Only happens to ONE strand of DNA –Uracil bonds with Adenine of the DNA

10. Steps of Transcription (cont’d) Ribonucleotides Bond: ribonucleotides of mRNA bond due to an enzyme Leaves Nucleus: mRNA strand breaks away from DNA and enters the cytoplasm (where translation begins)

11. Transcription to Translation

12. Translation Process of converting information in mRNA into a sequence of amino acids that will make a protein

13. Steps of Translation Ribosomes Attach: mRNA enters the cytoplasm where ribosomes of rRNA attach to it rRNA reads mRNA: rRNA slides down the mRNA and signals to tRNA to bring the right amino acid –Start codon (AUG) signals where to begin making the protein

14. tRNA tRNA has a clover- leaf shape with an anti-codon attached to one of the “leaves” and an amino acid attached to the “stem”

15. Steps of Translation (cont’d) tRNA brings amino acids: tRNA with the correct anti-codon arrives and temporarily bonds to the codon of mRNA rRNA slides and reads: rRNA continues to slide down the mRNA and reads next codon  new tRNA

16. Steps of Translation (cont’d) Amino acids join: an enzyme joins the amino acids (of tRNA) with peptide bonds –Once joined, the now amino acid free tRNA detaches from the mRNA strand –This process continues until a stop codon (UAA/UAG/UGA) is read

17. Transcription & Translation: END RESULT A chain of amino acids joined by peptide bonds  PROTEIN

18. Transcription & Translation Sequence Animation of Protein Synthesis

19. Protein Synthesis Video

20. References Transcription & Translation Images: http://www.brooklyn.cuny.edu/bc/ahp/BioInfo/SD.TransTr ans.HP.html http://www.brooklyn.cuny.edu/bc/ahp/BioInfo/SD.TransTr ans.HP.html Transcription & Translation Animation: http://learn.genetics.utah.edu/units/basics/transcribe/ Protein Synthesis Video: Messenger RNA, Transfer RNA, and Protein Synthesis. United Learning. 2001. Discovery Education. 15 December 2009