mixed midterms

[jinian]

Despite screwing up the salmon chloride cell question (by forgetting one channel, saying "that can't be right," and erasing the distinctive and correct Na⁺/2Cl^-/K⁺triporter in favor of balancing the ions), I came out with a bio exam score only two points below the highest in the class. They're lenient graders compared to my last bio folks, but since I'm sure they were lenient with everybody, I feel pretty good. My TA gave me a special grin when she handed it back. :)

On the other hand, I am really, really glad we get to drop one of our physics exam scores. REALLY. This was my worst test ever. I overanalyzed some stuff and didn't have notes for a few things we'd glossed over, and I'd felt anxious enough going in (yet still overconfident, ha ha) that those problems completely threw me out of any useful mindset. Valuable experience, I guess; now I know why so many people test poorly. Can that not happen again, please?

Both of these share a common theme: examples that I'd thought were just to illustrate a point appeared on the test, and I wasn't prepared. Next time I will be! And I'm glad one of them turned out okay.

Comments

[jinian.livejournal.com]

There are no free, easily findable diagrams of the salmon chloride cell on the web that I can see. I could certainly draw you one now, though.

[baratron.livejournal.com]

I thought it was an amusing typo! So, er, what is a salmon chloride cell?

[jinian.livejournal.com]

It's a cell that pumps out all the excess NaCl that diffuses into the salmon's gills when it's in seawater. When the smolt moves into brackish water and then seawater, it produces cortisol in response to the stress, and these cells respond to high cortisol levels by cranking out tons of ion-transporting proteins. One's the sodium-potassium pump that shows up everywhere, one's a distinctive three-ion transporter (the one I remembered and then erased), and there are some channels in the cell membrane on each side of the epithelium and in the tight junctions between the cells.

They actually gave me 8 of 12 points for my half-assed but balanced cell diagram, for which I am grateful.