Passing Genetic Notes in Class

1. Passing Genetic Notes in Class CC106 / Discussion D by John R. Finnerty

2. BioUNITY

3. LUCA Last Universal Common Ancestor Bacteria Archaea Eukaryota Unity & Diversity • metabolism • protein assembly • genetic material • genetic code

4. Metabolic Unity Use the same enzymes to digest sugars.

5. Molecular Unity Use the same molecular machinery to build proteins.

6. Genetic Unity Use DNA & RNA to transmit encoded information. & use the same genetic code.

7. CYSTEINE LEUCINE ISO-LEUCINE L I C Portion of a gene -C-T-A-T-T-A-A-G-T- DNA alphabet -G-A-T-A-A-T-T-C-A- gene is transcribed into a “message” c -C-U-A-U-U-A-A-G-U- RNA alphabet message is translated into a protein using the genetic code Protein sequence string of amino acids

8. E. coli bacterium Implication of Shared Genetic Code Human insulin gene Human insulin protein

9. Key Properties of the Code • Each codon (= word) is 3-letters long. • There is a reading frame. • The code is redundant: multiple words say the same thing. • The code is somewhat robust to errors. Not all mutations (= spelling mistakes) change the meaning.

10. I. Using the 1-letter abbreviations for amino acids, compose a note instructing your teammates to perform some action. 20 available letters: A C D E F G H I K L M N P Q R S T V W Y

11. II. Reverse translate your protein note into DNA letters (ACGT) using the genetic code. C T A G A A G C C A A T

12. II. Reverse translate your protein note into DNA letters (ACGT) using the genetic code. C G C T A G A A G C C A A T A IIa. Add 0, 1, or 2 dummy letters at the beginning and end to hide the reading frame.

13. III. Transmit note, now encoded in DNA form to another team, who will mutate 1 of every 5 letters. C G C T A G A A G C C A A T A C G T T A G A G G C C A A A A IIIa. Pass mutated message to intended recipients. C G T T A G A G G C C A A A A

14. IV. Recipients translate message (after being told the correct reading frame). C G T T A G A G G C C A A A A STOP R R P K

15. C G T T A G A G G C C A A A A IV. Recipients translate message (after being told the correct reading frame). C G T T A G A G G C C A A A A STOP R R P K L E K A

16. C G T T A G A G G C C A A A A L E K A V. Deduce what the message is supposed to say. • Clues: should direct me to perform an action. • Message would be mutated in 3 places. • But, not all DNA mutations would change the meaning of the message (the amino acid).

17. C G T T A G A G G C C A A A A C G T T A G A G G C C A A A A L E K A V. Deduce what the message is supposed to say. P E K E • Clues: should direct me to perform an action. • Message would be mutated in 3 places. • But, not all DNA mutations would change the meaning of the message (the amino acid).

18. C G T T A G A G G C C A A A A C G C C A G A G G A AA A A A L E K A V. Deduce what the message is supposed to say. P E K E • Clues: should direct me to perform an action. • Message would be mutated in 3 places. • But, not all DNA mutations would change the meaning of the message (the amino acid).

19. C G T T A G A G G C C A A A A C G T T A G A G G C C A A A A L E K A V. Deduce what the message is supposed to say. L E P A • Clues: should direct me to perform an action. • Message would be mutated in 3 places. • But, not all DNA mutations would change the meaning of the message (the amino acid).

20. C G T T A G A G G C C A A A A C G T T A G A G G C C C C A A L E K A V. Deduce what the message is supposed to say. L E P A • Clues: should direct me to perform an action. • Message would be mutated in 3 places. • But, not all DNA mutations would change the meaning of the message (the amino acid).

21. C G T T A G A G G C C A A A A C G T T A G A G G C C A A T A L E K A V. Deduce what the message is supposed to say. L E N A • Clues: should direct me to perform an action. • Message would be mutated in 3 places. • But, not all DNA mutations would change the meaning of the message (the amino acid).

22. Second letter in codon Third letter in codon First letter in codon