STUDY GUIDE
Proteins make up most of the "machinery" of the cell, and the proteins a cell produces ultimately determine most of its character. Cell differentiation is the process by which cell ends up expressing (producing) proteins that suit it for a specialized role. Which genes it transcribes into mRNA and translates into protein will largely determine that role.
Study Question 1:
Why do we need to transcribe DNA to mRNA at all in order to make protein? Why don't our cells just keep their ribosomes inside the nucleus and translate the DNA directly? Try to come up with a plausible answer to this question.
(Hint: You can think about it evolutionarily, or you can think about how many copies we have of a given piece of DNA, you can make an argument based on DNA's structure... there are many ways to answer this!)
Study Question 2:
Draw a picture of a gene being transcribed. Include RNA polymerase, the gene, the promoter region, transcription factors, and enhancers in the picture.
Briefly explain the function of each of these parts.

STUDY GUIDE
Study Question 3:
One of the more common mutations that causes the disease hereditary pancreatitis is shown below: mRNA SEQUENCE OF NORMAL:
AUG [...….] / CAA /CGC / CCG / CGU / GUC/ ……. mRNA SEQUENCE OF MUTANT:
AUG[…….] / CAA /CAC / CCG / CGU / GUC/ …….
Using the genetic dictionary in your lab manual (or a codon table from the
Internet), please explain what effect this mutation would have on the amino acid sequence produced. Would it be a missense mutation or a nonsense mutation?
Study Question 4:
In order to try to figure out how a protein, which we'll call Studyase, moves around in cells, I try to make a Green Fluorescent Protein (GFP) fusion. That is to say, I make a DNA sequence that combines the Studyase sequence with the GFP sequence, separated by a 27 base-pair linker encoding 9 amino acids. (A linker is a short sequence that acts like a spacer between the two proteins, keeping them from interfering with each other.) In this new protein, the GFP comes after the
Studyase.
* Would it be possible to make a human being express this fusion just by injecting them with the DNA? Why or why not?
* For some reason, I make a mistake in designing the linker; I make it 26 nucleotide bases long instead of 27. That is to say, between the end of the
Studyase sequence and the start codon of the GFP sequence, I place 26 "letters" of genetic code. Would the Studyase still be functional? Would it glow from the
GFP? Explain.