Course: Chemical Biology
Length: 6 units, total approx. 21 hours
School/platform: University of Geneva/Coursera
Instructor: Robbie Loewith, Marcus J. C. Long, et al
…[C]hemical biology straddles a nexus between chemistry, biology, and physics. Thus, chemical biology can harness rapid chemistry to observe or perturb biological processes, that are in turn reported using physical assays, all in an otherwise unperturbed living entity.
…We will discuss fluorescence as a general language used to read out biological phenomena as diverse as protein localization, membrane tension, surface phenomena, and enzyme activity. We will proceed to discuss protein labeling strategies and fusion protein design. Then we will discuss larger and larger scale chemical biology mechanism and screening efforts. Highlights include a large amount of new data, tailored in the lab videos, and a large number of skilled presenters.
I’ve often said that one of the drawbacks of moocs is that classes in a sequence can be separated by months or even years. A student enrolled in a biology program at an on-the-ground university would be taking bio and chem classes all the time, allowing for more reiteration and keeping the ideas in active brain storage; if six months elapse between bio classes, I forget what PCR is and have no idea what the RAS pathway is. And suddenly it occurred to me: I can do something about that! Wow, revelation. So instead of waiting around for the next in MIT’s cell biology series, or their continuation of general chemistry, I went looking for related classes. Though I had a couple of retakes in mind, I stumbled across this, and thought it might be interesting. Is there a difference between biochemistry and chemical biology? Turns out, yeah, but it’s a matter of emphasis: in biochem, it’s finding the result; in chembio, it’s figuring out how to get there.
I knew from the start this would be over my head, and boy, it sure was. A couple of lectures were just rivers of words floating by. But that’s one of the benefits of moocs: you can take a class that’s a little beyond your grasp, take away as much as you can, and save the rest as aspirational motivation.
I learned the difference between fluorescence and phosphorescence and all about the Jablonsky diagrams that spelled it out; I learned about membrane tension and the pathway that detects and adjusts for it; I got a good refresh on the properties of amino acids and things like the catalytic triad; and in more general terms, I dealt with assays at a level of detail that was scary. Oh, and plasmids, I’d forgotten everything I ever knew about plasmids. So it was very much worth it, though I often missed entire swaths of material. And, by the way, I passed, which should give someone pause about the utility of passing scores on moocs: I didn’t deserve to pass, yet I did. I put in the work, to be sure – I spent 51 hours on site rather than the 21 hours predicted – but a lot of my answers were the result of test-taking skills, guessing, and perseverance rather than knowledge.
The more aspirational material, saved for a later time, was fascinating. I’m still reeling at the different ways biological molecules and processes can be examined, both in vivo and in vitro. There’s the SNIFIT which generates one ratio of fluorescent colors when closed, and another in the presence of target molecules which open it. And photocaging, which keeps a molecule inert until activated by light, allowing precise targeting of the process under study. I’m a lot hazier on TREX, GREX and barcoded libraries, but even with minimal understanding they’re fascinating. Then there were uses of my old friends from the MIT Biomoocs SDS-PAGE and Western blots, which now seem a lot simpler.
Besides video lectures by several different professors, there were also several lab segments showing fancy machines and the people who operate them (these mostly went by me), and short Readings explaining individual concepts. Several Practice Quizzes showed up during each module; these required the 80% to pass, but didn’t count in the eventual overall score. They displayed what was right and what was wrong, and could be taken over and over until the desired score was obtained (the “choose all that apply” questions were kind of tricky); I ended up getting 100% on all, not to get the score, but to make sure I had the correct information. Each module also had a Final Quiz, which partly drew on those Practice Quizzes. The Final Quizes displayed nothing except a score for the first three modules; the last three modules displayed whether a question was right or wrong. These could only be re-taken after 72 hours. I had to retake a couple of them to get to the 80% passing score. And as I’ve said, that was mostly unearned, so I’m not putting any feathers in my cap.
For someone with a better chem baseline than I, this would probably be a great class for looking at these techniques in depth. For me, it was still a great class, just not in the way the instructors probably intended it. But some day I’m going to run across something like barcode libraries again, and I’ll be a little better prepared to understand it, now that I have some idea of where it’s going.
And now I’m going to take some additional chem and bio courses to keep me primed for the new moocs this summer; but now that I’ve had a stretch, I’m going to find something more within my level. Because stretching is great – once in a while.