Extremely interesting, as always. But, I just skimmed it and found a wrong number: ATP synthase rotates at about 8000 rpm, something like 100-300 rotations per second, producing 3 ATPs every turn (according to Alberts book)
I think we used the same source for ATP synthase. 200 rotations per second is in *real speed*. After the 10,000x metaphorical slowdown, that comes out to be 50 seconds per turn. Or did I do some math wrong somewhere?
No, that´s Ok. I just skimmed it over and didn't realize the metaphorical slowdown. I think the article would be very interesting anyway by just comparing all biological time scales , without the need to normalize them to one event (the channel opening). But maybe it adds prespective. I just need to read the article now in detail, not skimming it :)
Thanks a lot for providing this very nice overview of speed in biology. I agree, though, with some of the comments that adding the 10000x scaling makes the article harder to read and assimilate. (Probably helps others without STEM background, so I see why you did it...)
To contribute a bit (you did all the hard work :)), I asked ChatGPT to summarize it in a table (with only real times):
Internal molecular vibration speed: billions of wiggles per second
Water molecule average speed: ~1,300 miles per hour
Diffusion across E. coli width (1 µm): ~1 ms
Diffusion across skin-cell width (20 µm): ~0.33 s
Diffusion across hair width (100 µm): ~10 s
Transcription rate (RNA polymerase): ~50 bases per second
Typical bacterial gene transcription: ~20 s
Human gene transcription (with introns): ~10 min
Translation rate (ribosome): ~5 amino acids per second
What this really shows me isn’t that biology is chaotic, but that our intuition is the bottleneck. Molecules aren’t messy, they’re just operating on timescales we’re not built to feel. The slowdown metaphor works because it exposes how much of biology feels mysterious simply because it’s happening far outside human perception.
"So, for the sake of our metaphors, let’s imagine slowing down the opening of this [potassium ion] channel 10,000x, so it only takes as long as the blink of an eye. If this were the case, then…"
The rates given throughout the piece are in relation to this "slowed down" time, to help readers understand the relative times of molecular events. These are metaphorical rates, rather than actual timescales.
Thanks for your comment. We've updated the article to include real rates.
The point of the "quantitative metaphor" is to put molecular events into context, relative to a phenomenon that we can understand as humans; namely, the blink of an eye. That was the intention of the article, and we apologize if it was confusing. We could have done a better job conveying this.
Extremely interesting, as always. But, I just skimmed it and found a wrong number: ATP synthase rotates at about 8000 rpm, something like 100-300 rotations per second, producing 3 ATPs every turn (according to Alberts book)
Hi Miquel, thanks for reading!
I think we used the same source for ATP synthase. 200 rotations per second is in *real speed*. After the 10,000x metaphorical slowdown, that comes out to be 50 seconds per turn. Or did I do some math wrong somewhere?
No, that´s Ok. I just skimmed it over and didn't realize the metaphorical slowdown. I think the article would be very interesting anyway by just comparing all biological time scales , without the need to normalize them to one event (the channel opening). But maybe it adds prespective. I just need to read the article now in detail, not skimming it :)
Thanks a lot for providing this very nice overview of speed in biology. I agree, though, with some of the comments that adding the 10000x scaling makes the article harder to read and assimilate. (Probably helps others without STEM background, so I see why you did it...)
To contribute a bit (you did all the hard work :)), I asked ChatGPT to summarize it in a table (with only real times):
Internal molecular vibration speed: billions of wiggles per second
Water molecule average speed: ~1,300 miles per hour
Diffusion across E. coli width (1 µm): ~1 ms
Diffusion across skin-cell width (20 µm): ~0.33 s
Diffusion across hair width (100 µm): ~10 s
Transcription rate (RNA polymerase): ~50 bases per second
Typical bacterial gene transcription: ~20 s
Human gene transcription (with introns): ~10 min
Translation rate (ribosome): ~5 amino acids per second
Typical protein translation: ~1 min
Fastest folding proteins: ~2 µs
Typical protein folding: ~0.3–8 s
GFP maturation: ~1 hour
Potassium channel gating (outer conformational change): ~100 µs
Potassium channel gating (inner conformational change): ~10 µs
ATP synthase rotation: ~200 rotations per second
E. coli flagellar rotation: ~30 rotations per second
Vibrio flagellar rotation: ~2,000 rotations per second
Superoxide dismutase max catalytic rate: ~100,000 reactions per second
Typical enzyme catalytic rate: ~10 reactions per second
Kinesin motor step: ~3 ms
Yeast protein half-life (median): ~45 min
Shortest yeast protein half-life: ~3 min
Longest yeast protein half-life: ~8 days
Human fibroblast protein half-life (median): ~2.5 days
Ornithine decarboxylase half-life: ~10 min
Collagen protein lifetime: ~120 years
DNA polymerase base addition: ~600 bases per second
DNA polymerase active binding per event: ~1.5 min
E. coli division time (fast growth): ~30 min
Human fibroblast division time (culture): ~20 hours
Fibroblast cell cycle G1 phase: ~7 hours
Fibroblast cell cycle S phase: ~9 hours
Fibroblast cell cycle G2 phase: ~3 hours
Fibroblast cell cycle M phase: ~50 min
Fruit fly lifespan (lab): ~1 month
Access 1 byte from DRAM: ~100 ns
Access 1 byte from SATA hard drive (HDD): ~10 ms
Car engine combustion cycle: ~30 µs (≈2,000 RPM)
Jet engine turbine rotation: ~4 µs (≈15,000 RPM)
TV refresh (LED flat screen): ~8.5–17 ms
30 FPS video frame: ~33 ms
Movie frame (24 FPS): ~42 ms
Analog watch one-second tick: ~1 s
Thank you again!
The idea of asteroid mining is often framed as a futuristic solution to Earth’s resource problems. Our latest UNSW Science story looks at the scientific reality behind the hype — and what still stands in the way.https://open.substack.com/pub/unswscience/p/how-close-are-we-to-mining-asteroids?utm_campaign=post-expanded-share&utm_medium=web
What this really shows me isn’t that biology is chaotic, but that our intuition is the bottleneck. Molecules aren’t messy, they’re just operating on timescales we’re not built to feel. The slowdown metaphor works because it exposes how much of biology feels mysterious simply because it’s happening far outside human perception.
Is this correct?
These rates are SCALED according to this line:
"So, for the sake of our metaphors, let’s imagine slowing down the opening of this [potassium ion] channel 10,000x, so it only takes as long as the blink of an eye. If this were the case, then…"
The rates given throughout the piece are in relation to this "slowed down" time, to help readers understand the relative times of molecular events. These are metaphorical rates, rather than actual timescales.
How does this help? This is extremely confusing tbh
Thanks for your comment. We've updated the article to include real rates.
The point of the "quantitative metaphor" is to put molecular events into context, relative to a phenomenon that we can understand as humans; namely, the blink of an eye. That was the intention of the article, and we apologize if it was confusing. We could have done a better job conveying this.