Spyke

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40 replies

I teach cell biology. This is not an acceptable model. Kinesins don't lift their feet to walk. This is a Disney version of the mechanism.

6
Jordan117reply
lemmy.world

How is it more accurate? I thought that in reality the "steps" are incredibly fast, but that makes it seem like it's a much slower and more uncertain process.

1
yeahiknow3reply
lemmings.world

Fast relative to what? The point is that the kinesin protein doesn’t “walk” any more than floating debris “swims.”

10
Jordan117reply
lemmy.world

Relative to the speed shown in the visualizations. The pop-sci animations look like it takes one step every second or so, while in reality they do hundreds per second.

1

Whoa, does that mean they cool the cell as they walk? They are transferring energy from the Brownian motion which on average would result in a lower temperature in the surrounding particles.

1

Well you can tell by my bind to tubulin
This motor protein ain't stoppin'
Walkin' the line from A to B
Replenishing the ATP

13

Because they probably don't understand even basic music theory. Unfortunately far too many people don't.

3
europe.pub

Imagine if that protein suddenly gained conciousness and decides to meditate to gain higher spiritual awakening instead of transporting hormones.

15
kadureply
lemmy.world

Then a friendly little chaperone protein would come and beat the living shit out of it until it folded itself again and stopped meditating, back to work :)

18

"But I would walk 500 miles
And I would walk 500 more
Just to be the protein who walks a thousand miles
To deliver cargo to your core" ♫

11
lemmy.world

Do they move this slowly? Or is this animation in bullet time?

11

IIRC it's like 10.000 times faster (I can be wrong but then it's probably way faster).

13

I guess this depends on environmental conditions such as

  • temperature
  • acidity of the internal cell environment
  • how available is energy? My guess this mechanism is powered by ATP?
9
Schmooreply
slrpnk.net

This animation isn't just sped up, it's also simplified. In reality they don't take steady, purposeful steps. They spaz out with random vibrations (Brownian motion) until the "foot" clicks into place by random chance, then the other one releases and the process repeats. It's like shaking a container filled with legos until they assemble themselves. The proteins are just shaped in such a way that "walking" is the most probable outcome.

6

The animation is actually slowed down. Kinesin can take something like 100 steps per second. Each step is about 8 nm, and they've been observed to move 600-1000 nm per second.

In reality it wiggles around in Brownian motion but the equilibrium of it "clicking" into place is so attractive that it keeps happening really fast.

2

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Kinesin Protein | Spyke