science

A protein emerges from the ribosome as a linear chain of amino acids. Within milliseconds to seconds, it folds into a precise three-dimensional structure—a shape that determines its function. This is the protein folding problem, and it's fundamentally a free energy problem. The native structure is the

We've traveled through Gibbs free energy from formula to function—from ΔG = ΔH - TΔS to protein folding, membrane potentials, and the persistence of diamonds. Now we step back. What does it all mean? Free energy is not merely a thermodynamic quantity. It's the master variable

Every neuron maintains a voltage across its membrane—about -70 mV inside relative to outside. This isn't a trivial detail. It's a thermodynamic battery, charged by burning ATP and discharged to send signals. Membrane potentials store free energy in ion gradients. Sodium is concentrated outside, potassium

At room temperature and pressure, graphite is more stable than diamond. The free energy of graphite is lower by about 2.9 kJ/mol. This means every diamond should spontaneously transform into graphite. Your engagement ring should slowly become pencil lead. It doesn't. Diamonds persist for billions of