Quizzam 2 Review Flashcards
What is a plasmid and why is there one in the yeast that we are using for our experiments?
A plasmid is a double stranded covalently closed circular DNA that is capable of reproducing. We use it in our experiments because the yeast (s. cerivisae) can’t produce p53 by itself, so the p53 plasmid is injected into the yeast.
What is an auxotrophic mutation?
A yeast strain that carries a mutation. As a result, these strains need a specific amino acid or purine/pyrimidine base to grow.
What is the difference between lacZ and ONPG?
LacZ is the name of the gene that codes for the protein (beta-gal). Whereas ONPG is a chemical analog of lactose, which is then hydrolyzed by lactase.
Why do we use ONPG?
With ONPG, it gets hydrolyzed into galactose and ONP. ONP has a yellow hue that can be measured because if we were to use lactose, which is the natural form, it would be harder to measure.
Why should you expect all yeast to stay white on a high ADE plate?
Because the ade2 needs a high [adenine], so it can grow on the plate.
What is the difference between an independent and a technical replicate?
An independent replicate is a test performed on biologically distinct samples representing an identical time point, treatment dose(s). Whereas a technical replicate is where a single experiment is taken from the same sample.
What does it mean if a plasmid has leu2 (italics) in it, and what are the implications that has on the cell?
It means the plasmid requires the amino acid leucine for growth. This means the plasmid does not have the ability to produce its own leucine.
What are the positive and negative controls we used for our spot assay and why are we using them?
The positive control is the p53 wild type in the high [adenine] plate, and the negative control is the p53 deletion in the low [adenine] plate. We use them to determine which p53 strains are binding to the p21 RE. We also use it to ensure the experiment is working correctly.
What would happen if we tried to run our experiments on yeast that did not have the plasmid with p53 gene?
Nothing would happen, because the yeast (s. cerivesiae) does not produce it’s own p53.
What does it mean if yeast has a ura3 (italic) mutation?
This yeast strain has a mutation where it requires the pyrimidine base, uracil to grow.
Imagine you found a drug that you think kills yeast and you want to test your hypothesis. How could you set up an experiment with a positive and negative control?
The positive control would be of the yeast dying and the negative control would be of the yeast remaining alive after making contact with the drug.
True or False?
Results should always go in the legend.
True
True or False?
Methods sections should always explain exactly what you did in lab making sure to include any mistakes thoughts and feelings.
False
True or False?
Table legends go above the table.
True
True or False?
Figure legends go above the figure.
False
