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Living cells are very fast and crowded places (2012)

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Re: Living cells are very fast and crowded places (2012)

#61

Post by charlieflowers »

koliber wrote: post #52
mncharity wrote: post #16

> cells are extremely crowded and busy places Cells are extremely crowded and busy... and random and violent places. Molecular biology dances in a nano moshpit from hell. The Inner Life of a Cell is badly misleading. It reinforces many educationally toxic misconceptions. Yes, the graphics technology was limiting. But the video doesn't attempt to mitigate the negative impact. For instance, adding a couple of frames of…

Thank you for this writeup that peels away a layer of simplification and more vividly and accurately explains what is going on. you have a way with words. The intoxicated panicked mouse will stay with me forever. That being said, I don't agree that it is a pervasive problem that simplification and abstraction is used in teaching. New concepts have to be introduced piecemeal. If a new topic was explained to an audienc…

> you have a way with words. The intoxicated panicked mouse will stay with me forever.

I like "random walk on a leash" too. Powerful and descriptive.

Re: Living cells are very fast and crowded places (2012)

#62

Post by erasmuse »

koliber wrote: post #52
mncharity wrote: post #16

> cells are extremely crowded and busy places Cells are extremely crowded and busy... and random and violent places. Molecular biology dances in a nano moshpit from hell. The Inner Life of a Cell is badly misleading. It reinforces many educationally toxic misconceptions. Yes, the graphics technology was limiting. But the video doesn't attempt to mitigate the negative impact. For instance, adding a couple of frames of…

Thank you for this writeup that peels away a layer of simplification and more vividly and accurately explains what is going on. you have a way with words. The intoxicated panicked mouse will stay with me forever. That being said, I don't agree that it is a pervasive problem that simplification and abstraction is used in teaching. New concepts have to be introduced piecemeal. If a new topic was explained to an audienc…

Yes, our understanding gets more refined the more we learn. It remains messy, error-prone and incomplete. So the solution can never be to learn things 'well' or get things right first time or produce perfect teachers/videos or something like that. The solution is to go on correcting misconceptions where we are interested. Ken Shirriff's blog, mncharity's website, comments here and so on simply are part of the ongoing spontaneous correction process. Like the contents of a cell, they may look crazy and disorganised but they get the job done.

Re: Living cells are very fast and crowded places (2012)

#63

Post by crusso »

haihaibye wrote: post #56
100ideas wrote: post #25

Earlier quoted context omitted.

If all you had was unix kernel machine code, could you really use it to engineer the hardware required for it to go inside of?

This is a bad analogy - the instructions for making everything in the cell is in the dna, so you also have the blueprints for the hardware fabrication plant.

Don't some features of the cell that you get from your mother replicate themselves, like your mitochondria?

Granted, mitochondria have their own DNA - but aren't considered part of the human chromosome.

Besides mitochondria, isn't there a whole cellular bootstrap environment that the DNA doesn't specifically encode for?

Re: Living cells are very fast and crowded places (2012)

#64

Post by agumonkey »

hyperpallium wrote: post #55

The information processing capability of cells, and the fact that single-celled creatures have behaviour, makes it hard for me to believe that neurons (not just in humans, in all animals with neurons) don't use any of this information processing capability. I understand researchers have claimed to replicate the brains of some very simple animals (having something like 306 neurons)... but have they replicated the beha…

IMO the internals are already busy being the fundation for the externals .. I don't think there's a strong information channels between the two.

Re: Living cells are very fast and crowded places (2012)

#65

Post by Retric »

robinduckett wrote: post #48
visarga wrote: post #23

Earlier quoted context omitted.

Think about this: your body is made of protein, each protein molecule is being created by copying a sequence of DNA. So your DNA has to do a LOT of copying, and for each copy it has to be cut open and put back together. In fact DNA is working hard every single day to keep us alive - it's not just sitting there until cell division. Even duplicating itself is no small feat - the total length of DNA in a human is 10B mi…

It's 7.5 billion miles to pluto one way. Total length of all DNA strands in the human body: 744 million miles. So you're off a bit.

Rather than just stating random numbers:

DNA in a cell is ~2 meters long (rolled up it's 6 microns across) http://www.sciencefocus.com/qa/how-long-your-dna * ~40 trillion cells (https://www.smithsonianmag.com/smart-news/there-are-372-tril...) ~= 8e13 meters ~= 5 * 10 ^ 10 miles or ~50 billion miles.

Re: Living cells are very fast and crowded places (2012)

#66

Post by JshWright »

ekianjo wrote: post #31
JshWright wrote: post #19

Earlier quoted context omitted.

And a lot of those blobs aren't even 'you'...

Not that many actually, the estimations about people being made of more non self stuff than selfstuff were based on no serious measurement and its more of an urban legend than a fact.

I was referring to the number of blobs, not their mass.

Re: Living cells are very fast and crowded places (2012)

#68

Post by elboru »

Ultimatt wrote: post #40
ngsekar wrote: post #37

Interesting.... Its very difficult to think about works of cells... if god is there... he is so great of creating lifes...

If god was so great (or at least smarter than humans) most of it would work a lot better than it does!

Care to explain? What could be improved?

Re: Living cells are very fast and crowded places (2012)

#69

Post by torbjorn »

elboru wrote: post #68
Ultimatt wrote: post #40

Earlier quoted context omitted.

If god was so great (or at least smarter than humans) most of it would work a lot better than it does!

Care to explain? What could be improved?

I keep getting eye lashes in my eye for one.

Re: Living cells are very fast and crowded places (2012)

#70

Post by 100ideas »

abecedarius wrote: post #47
100ideas wrote: post #45

Earlier quoted context omitted.

> Also, speeds like "100 times per second" should be scaled down with the size scaling, if you want a feel for mechanics. I'm a little confused, are you saying that the real speeds and rates in the article/this thread are all too fast by a factor of 100 million, or are you saying that its useful to perform this scaling mentally when imagining these systems to get a better intuition of their mechanics...?

The latter. Maybe I should reread the post, but it invites you to visualize a cell as Times Square -- scaling the sizes -- and then the unscaled speeds give the wrong impression within that visualization. (Mechanical properties like stiffness don't vary when you scale space and time together.) Outside of it, of course the absolute speeds are what you want to know.

Thanks for the clarification, I see what you’re getting at.
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