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Central Dogma Assignment

Print Name ___________________________________________

Directions: Complete this worksheet after listening to the Central Dogma recorded lecture posted

on Blackboard. Each student will turn in his/her individual worksheet at the beginning of class.

COMPLETE THE TABLE. LABEL YOUR 5’ AND 3’ ENDS.

YOU MUST GET THE ENTIRE TABLE CORRECT FOR CREDIT. NO PARTIAL CREDIT.

DNA template (-) 5’ GTACTATTAATT TACTGGGTGCAT CCGCATGGTACG 3’

DNA coding (+) strand

mRNA (+) codons

Only write the tRNA

anticodons for actual

codons coding for

amino acids

amino acid sequence

1. You isolate and sequence a novel cytoplasmic membrane protein from Staphylococcus aureus that appears to function in the transport of cations into the cell. A colleague working in a competing lab

in France isolates a cytoplasmic membrane protein from Streptococcus pyogenes that appears to have

the identical function as your protein. In fact, the primary structure of the S. pyogenes protein is

identical to the S. aureus protein. Does this mean that the genes for these two proteins are identical in

Staphylococcus aureus and Streptococcus pyogenes? Explain your answer.

2. What is the effect of DNA mutation on protein sequence?

3. In sickle-cell disease, the replacement of A by T at the 17th nucleotide of the gene for the beta

chain of hemoglobin changes the mRNA codon as shown below (in red).

Wild-type mRNA 5’… A C U C C U G A G G A G…

Sickle-cell mRNA 5’… A C U C C U G U G G A G….

a. What amino acids are encoded by the two mRNAs?

Wild-type amino acids:

Sickle-cell amino acids:

b. What kind of mutation does this cause in the protein?