Given that this week's chapter is all about cell biology, I thought I'd post some links to a few interesting videos I've found on YouTube.
The first is something of an epic, an 8 min animation which took a team at Harvard 14 months to complete: http://youtu.be/uGK9CYetCvM (I have something of a love/hate relationship with this video and I'm keen to hear your thoughts!)
The next three are a series which all describe mitosis in increasing detail, each offering a slightly different perspective.
The next two are molecular dynamics simulations, not the best examples but the best I could find. I think they give some indication of the "messiness" down at the near-atomic scale.
The first video posted is most definitely an epic on the life inside a cell. I've seen in played in every biology course I've taken. Being somewhat of a film junkie, I must say it's well put together and even makes somewhat of a narrative out of cellular function. I think the depiction of the assembly and dis assembly of microtubules and the complexity of it,is genius. I think it's a good illustration to go with the forum we all had last Friday, regarding entropy - energy transfer can result in increased order.
ReplyDeleteThe only criticism that I'd have about this animation is the part where it shows Kinesin "walking" down the microtubule substrate. I seem to recall that last year in BIPH2000 we discussed at length how there's no swinging of the globular-head part forward during each step (as there's not inertia), which is an assumption commonly made. It would have been better if it showed the heads in random motion before being in close enough proximity to bind to the substrate's subunit.
However, I may just be being nit-picky.
The second last animation posted is probably the most accurate microscopic representation I've seen. This animation should be used more often.
ReplyDeleteMy question is whether these videos are intended to be accurate depictions of the inside of a cell. From the way the first one is set out I would assume that it is really aimed at the basic-biology or layperson audience, rather than the biophysicist or physicist.
ReplyDeleteWith this audience it is perfectly acceptable to ignore the facts of thermal motion and randomness,instead emphasising the ordered structures that they are capable of producing (with the correct manipulation of the cell conditions).
For a lower-level cell-biology course or similar thermal motion just complicates things! Cells are complicated enough already...
I suppose it is a little like Newtonian mechanics... "Hey guys, we can explain the motion of everything with this stuff... unless it is moving too fast or is too small or is in an intense gravitational field or..."
Martin, thanks for the links to the video. I have seen the first video in almost every biology/ biochemistry course I've taken so far, and the lecturers who have shown this in class praised the model.
ReplyDeleteI find the videos to be more biology oriented rather than physics but I think the main point of those videos is (aside from the obvious cell biology) to illustrate that the cell relies on entropy to function properly. A cell needs to escalate up to an unstable state in order to produce some form of useful work.