Tuesday, February 14, 2012

Acing Upper Division Biochem

My study guide for those who are taking it for premed, prevet, predent (do you have to?) prepharm, preprofessional.

When this semester started, I was told I had the hardest biochem professor at the university, that his tests are hard, that I should never ever underestimate them, and that I should likewise, get a 95 in his class overall.

Those words came from the professor himself and were echoed by the students in my other classes.

Here's what I'm doing so far and apparently, it is working:

1) I drew amino acids until my eyes bled. Every night, I drew them all. At first it was slow and painful. Mixing up the bonds on histidine and tryptophan (not the molecules, just the bonding on the aromatic rings). Along with the structures came the names, three letter abbreviations, and the single letter as well. As it got easier and I got less of them wrong, I started doing them as fast as I could. Before the midterm, I was able to get all 20 down on the paper in less than 5 minutes. No errors.

2) With the amino acids known, I started understanding their properties. Acid, base, polar, non-polar, non-anything (glycine), aromatic; and incidentally, I also memorized the pk's where given (R = 12.5, for instance). Then I made sure I knew what that meant as in, which hydrogen will leave the party first under which conditions. Knowing the pk's helped immensely and as I got closer to the midterm, it helped with playing "biochem games"

START, FART, YAR, WEAR, QWEEN, and any others I could think of were drawn at different pH's. What did this force?

It forced me to think about which atom was deprotonated at which point - did the alpha carbon lose its protons? or did the "R" group histidine lose its? And how, exactly, does one handle the protons on the arginine at pH 4.3 (the two on the backbone get lost to the peptide bond, the others stay put and the alpha carboxy loses it's H off the bat).

I loved word games when I was a kid. Find a word. Scrabble. Literati when Yahoo! first launched games on its site back in the 90s. Biochem has become that.

And I continue to draw the amino acids now. Every day. And I continue to make sure I can draw the "words" in biochem as well, along with knowing all the charges on the residues and the overall charge.

3) I'm drawing the mechanisms (yeay for ochem) for the enzymes. I do not know if we will be tested on it but given we're drawing them in class, I suspect I will have to know these too. So my sketch book now has amino acids, and enzyme mechanisms. Along with the mechanisms, I'm drawing all the graphs for Vmax, Km, and making sure I can explain in writing why the double reciprocal matters and what the lines actually tell me (its the inverse of the initial thought).

And last, I'm getting my sleep... and I'm enjoying my life a bit more.

Ochem sucked every ounce of energy I had, each and every weekend until the last day when I was told:

"Why take ochem 2? You don't need it!"

The sun shone brightly that day. And I'm LOVING biochem!

More tips/hints/tricks to come :)

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