KEY CONCEPT Translation converts an mRNA message

1. KEY CONCEPT Translation converts an mRNA message into a polypeptide…protein.

2. FROM GENES to PROTEINS - Translation converts mRNA recipes into needed polypeptides. • Part 1 – TRANSCRIPTION… FROM DNA TO RNA Transcription – how DNA sends messages -> RNA “recipes” • Part 2 - TRANSLATION… FROM RNA TO PROTEINS

3. Transcription Questions

4. FROM GENES to PROTEINS - Translation converts mRNA recipes into needed polypeptides. • Part 1 – TRANSCRIPTION… FROM DNA TO RNA Transcription – how DNA sends messages -> RNA “recipes” • Part 2 - TRANSLATION… FROM RNA TO PROTEINS

5. codon for methionine (Met) codon for leucine (Leu) Amino acids are coded by mRNA base sequences. • A codon is a sequence of three nucleotides that codes for an amino acid in the protein ”recipe”. “Butter” “Onions” …tomatoes?

6. Amino acids are linked to become a protein. • An anticodon is a set of three nucleotides that is complementary to an mRNA codon. • An anticodon marks a tRNA with a specific amino acid.

7. Proteins needed by your body are polymers. • Proteins are Polymers (Chains!) • Proteins are made of Monomers =1 Amino Acid at a time • Amino Acids are carried by Transport RNA (tRNA) • The Amino Acids ingredients a Protein are linked by Peptide Bonds

8. Ribosomes consist of two subunits. • The large subunit has three binding sites for tRNA. • The small subunit binds to mRNA. Up Next: Video Clip!

9. Wiki watchers! Go to www.dnai.org/a/index.html to watch this video: Click tab 3 Reading the Code, choose last Frame Put It Together, click Translation

10. From Genes to Proteins– the RNA-team Translates DNA’s message

11. For translation to begin, the three “friends” must assemble: tRNA binds to a start codon (mRNA) and signals the ribosome to assemble. • Exposed codon attracts complementary tRNA molecule, bringing its amino acid close to the first amino acid.

12. 2) Ribosome helps form a polypeptide bond between the amino acids. • 3) Ribosome pulls the mRNA strand the length of one codon.

13. 4) The now empty tRNA molecule exits the ribosome. • 5) A complementary tRNA molecule binds to the next exposed codon. • 6) Once the stop codon is reached, the ribosome releases the protein and disassembles.

14. A change in the order in which codons are read changes the resulting protein. • Regardless of the organism, codons code for the same amino acid.

15. www.classzone.com Biology 2010 Animated Biology Unit 3- CH 8 “Build a Protein” It does take time to load, so be patient. The tutorial will help you practice… Gene Expression = Protein Synthesis Transcription + Translation = Protein Your Turn! www.dnai.org/a/index.html Click tab 3 Reading the Code, last frame Put It Together, then Interactive

16. We can use our knowledge of Base Pairing Rules to work forward or backward in a DNA decoding challenge. What would be the mRNA message that called up this anticodon? __ __ __ Methionine is called by the “start” signal codon.

17. The genetic code matches each RNA codon with its amino acid or function. • The genetic code matches each codon to its amino acid or function. • one start codon, codes for methionine • three stop codons

18. Codon = Amino Acid AUG – GGC- CGU- AGC- UAU- CGU- UAG- Met Gly Arg Ser Tyr Arg Stop

19. UUA AAU Think! Do you need Codon or Anticodon? LEUCINE

21. For your homework: Be a DNA Decoder !