Junior Qualifying Examinations

So at Reed you have to pass a junior qualifying examination before you can register for your senior thesis. As an interdisciplinary major, I had to take both biology and chemistry. Biology was an open note/book/internet exam basically based on my coursework. I wrote an essay about haploinsufficiency in Marfan's syndrome fibrillin-1 gene and the elastin gene in Williams' syndrome and another essay where I wrote about the growth hormone axis and how nutrition (both being malnourished and obese) affected this axis. I also did some quantitative questions like calculating Tms of DNA strands and making buffers. I should hear back about it soon, although I'm afraid I might have gotten a conditional pass from messing up calculating TRIS on that buffer question, eeek. It's not a big deal if that happens, I just need to fix what I got wrong.

The chemistry qual was an oral exam where I was given this paper and had to learn as much as I could about it in 48 hours. Then they asked me questions, specifically about the paper, but really probing my organic chemistry knowledge as a whole. I had two options, an organic option and a biochem option, and I decided to go with the organic option. The biochem option was interesting too, it was on nicotine binding in the brain and how it is different from its inhibitory effects on your muscles (if it did hit the receptor in your muscles you'd be dead). But ultimately I felt more comfortable with the sort of questions they would ask in an organic qual, especially since my advanced synthetic final last semester was in the exact same format. Luckily, my organic paper was a synthetic paper and not a mechanistic paper--because for some reason the long lists of data tables with numbered compounds in mechanistic organic papers followed by colums of de's and ee's result in my eyes glazing over a lot of the time.

I think it overall went well. A lot of the questions were definitional--what is the kinetic enolate vs. thermodynamic enolate, what is an allene functional group, what is "latent stereochemistry". The main places I got tripped up on were mechanisms. I had this divinyl oxy-anion cyclopropyl Cope rearrangement mediated by a Brook rearrangement, and I started off drawing the reaction in a different perspective than I had in my notes which kind of threw me. The paper went to great pains to discuss why this enolate attacked from the more sterically hindered side (because it was reversible and resulted in the more stable transition state for the subsequent Cope) but to demonstrate it only showed what didn't happen due to steric repulsions--so there was no picture to look at what did happen. Which I knew, but it's just sort of difficult to pull all of that together visually on the board with weird bicyclic systems and the boat transition state and so forth. It went ok, I just had a moment where I was like "wait Connie..."

The other place I got tripped up due to nerves was the mechanism for oxidizing an enolate with a Davis oxaziridine. Again, it was ultimately ok, just a little bit of nerves. Also drawing 7 and 8 membered rings on the whiteboard was tricky!

The spectroscopy portion was easy since they had already assigned the peaks in my paper and my profs didn't ask me anything too difficult. Just like, why methyl groups attached to silyl groups were more upfield than methyls attached to carbons and whether this one set of diastereotopic methylnes were chemically equivalent or not, and why they had different J-values coupling to a neighboring proton that sort of thing.

It also struck me last night that wow, college has crammed a lot of chemistry into my head in the past 2 years.

So I should be hearing back about whether I passed, conditionally passed, or failed those shortly.