It costs time and energy to build the perfect protein, and there are tens of millions of them in each cell. If either time or energy is limited (and the faster you live, the less you will have of each to spare), then it’s only a matter of time before some proportion becomes dysfunctional. The question is, does that matter? The answer depends a grea

This is the strange world of metabolic flux. Even a simple bacterial cell can undergo as many as a billion transformations per second,

Once you think about electrical fields, it is hard to imagine anything else.

Krebs-cycle intermediates such as succinate and citrate begin to leak from the mitochondria into the cytosol, where they can stabilise transcription factors such as HIF1α, switching on genes that promote growth and inflammation – and tragically, as we age, cancer. This amounts to an epigenetic shift in the profile of gene activity linked with older

The oceans themselves have turned into fuel. That distant thermonuclear reactor, the sun, ignites the

some extent, individual tissues maintain a stable metabolic balance by importing or exporting each other’s waste products

it’s much easier to pass electrons onto carbon atoms in an acidic environment, where protons are abundant,

A single molecule of glucose could produce between thirty and thirty-six molecules of ATP through aerobic respiration, but only two molecules of NADPH

Could it be that the origin of life structured metabolism through the reactions of H2 and CO2, to form Krebs-cycle intermediates? That this biosynthetic engine was hard-wired into life from the beginning, the driving force that gave rise to genes and proteins? That billions of years later, as the atmosphere filled with oxygen, the Krebs cycle flipp