8 Comments
User's avatar
Mackenzie Noon's avatar

Nice article! One small clarification: I don’t think it’s quite accurate to describe Gibbs free energy as “an idealized thermodynamic floor that doesn’t account for real-world inefficiencies like energy lost as entropy or heat,” since Gibbs free energy explicitly includes entropy (and enthalpy) in its definition. That said, the broader point is fair — Gibbs free energy represents a theoretical minimum and doesn’t account for many practical inefficiencies.

Expand full comment
Adam Kaufman's avatar

What? On the order of a joule to assemble a cell is preposterously large. If it masses one picogram, that’s an energy density of 1e12 joules per gram. Compare that to TNT at 4e3 joules per gram or plutonium at 9e7 joules per gram. In other words, building my body (7e4 grams) would require almost as much energy (7e16 joules) as the largest nuclear bomb ever detonated (2e17 joules). If that’s meant to be an upper bound, it’s a pointlessly high upper bound. Maybe you have misreported the units?

Expand full comment
Niko McCarty's avatar

Hey Adam, you're absolutely right. My calculations were way off. I've corrected the article. Thank you for flagging this error!

Expand full comment
Adam Kaufman's avatar

I really enjoyed the rest of the article! Apologies if I was too rude in calling out that statistic

Expand full comment
Asimov Press's avatar

Not rude at all. We appreciate the callout!

Expand full comment
BabbleOn's avatar

I think your right that something is off. Estimates of the amount of ATP required for E. coli cell division are in the 10^10 - 10^11 range. Which is equivalent to nanojoules of energy. 0.72 joules is 9 orders of magnitude higher.

Expand full comment
Allan Konopka's avatar

This comment not directed at you, Niko but at Ortega-Arzola et al: a variant of '30 minutes in the library will save you weeks in the laboratory.' This was all articulated/calculated in Physiology of the Bacterial Cell: A Molecular Approach -- Neidhardt, Ingraham and Schaechter (1989). I no longer have my copy to check the correspondence. Note that the book also explains *why* E. coli grown in LB has more ribosomes etc than in minimal media. TL;DR faster-growing cells need to synthesize their major auto-catalytic component (proteins) faster and that requires more ribosomes per cell.

Expand full comment
Nabeela Farheen SN's avatar

Superb explaination 👏👍

Expand full comment