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[return to "Ask HN: What scientific phenomenon do you wish someone would explain better?"]
1. umvi+go[view] [source] 2020-04-26 22:20:34
>>qqqqqu+(OP)
I would like to understand how cellular biology processes actually work. Like, how do all the right modules and proteins line up in the right orientation every time? Every time I watch animations, it seems like the proteins and such just magically appear when needed and disappear when not needed [0]. Sometimes it's an ultra-complex looking protein and it just magically flys over to the DNA, attaches to the correct spot, does it's thing, detaches, and flies away. Yeah right! As if the protein is being flown by a pilot. How does it really work?

[0] https://youtu.be/5VefaI0LrgE

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2. Jabavu+ZC[view] [source] 2020-04-27 00:29:38
>>umvi+go
They don't. This is a pet-peeve of mine, and it's reinforced by animation after animation.

Everything is being jostled around randomly. The molecules don't have brains or seeker warheads. They can't "decide" to home in on a target.

The only mechanisms for guidance are: diffusion due to concentration gradients, movement of charged molecules due to electric fields, and molecules actually grabbing other molecules.

It's all probabilities. This conformation makes it more likely that this thing will stick to this other thing. You may have heard that genes can be turned on or off. How? DNA is literally wound on molecular spools in your cell nuclei. When the DNA is loosely wound other molecules can bump into it and transcribe it -- the gene is ON. When the DNA is tightly spooled, other molecules can't get in there and the gene is OFF for transcription. There's no binary switch, just likelihoods.

Everything is probabilistic, but the probabilities have been tuned by evolution through natural selection to deliver a system that works well enough.

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3. kcolfo+NE[view] [source] 2020-04-27 00:47:23
>>Jabavu+ZC
Even diffusion isn't some magical force guiding chemicals through the medium. It's just random movement that statistically results in the chemical being spread out. This is the same principle that the 2nd law of thermodynamics is based upon. There's nothing magic to it, it's just the statistically likely end result over many particles.
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4. Jabavu+BG[view] [source] 2020-04-27 01:04:42
>>kcolfo+NE
Yes. It's interesting how powerful and clarifying this model of its-all-just-atoms-bumping-into-atoms is. It's interesting how many people take science courses, but don't really get this.

In the context of Covid19, I see so many people wearing PPE, but failing to act as though they understand that the actual goal is to prevent this tiny virion dust from entering your orifices. Like wearing gloves and a mask, but then picking up unclean item in store then using now unclean gloves to adjust mask and make it unclean.

People seem to think of things as having essences or talismanic effects. Like gloves give you +2 against covid and a mask gives you +5 when it's really all about preventing those virus things from bumping into your cell things.

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5. lifefo+4L[view] [source] 2020-04-27 01:55:23
>>Jabavu+BG
Masks are for keeping your own particles from spreading far, not the other way around.
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