ideasthesia

Sign in Subscribe

foundations

Protein Folding: Free Energy's Masterpiece

Protein Folding: Free Energy's Masterpiece

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

Synthesis: Free Energy as the Master Variable

Synthesis: Free Energy as the Master Variable

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

Membrane Potentials: Free Energy Across the Cell

Membrane Potentials: Free Energy Across the Cell

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

Diamonds and Graphite: Thermodynamics vs Kinetics

Diamonds and Graphite: Thermodynamics vs Kinetics

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