mTOR Decision-Making System A Molecular System That Makes Decisions Among the thousands of molecular systems operating inside a human cell, few coordinate as many different activities as mTOR. Its name, mechanistic target of rapamycin, makes it sound like simply another enzyme. Technically, mTOR is a protein kinase: it transfers phosphate groups to other proteins and thereby changes their behavior. But describing mTOR merely as a kinase is like describing a brain as a collect

From a Primitive Energy Sensor to the Master Guardian of Cellular Energy Long before animals, plants, or the first eukaryotic cells existed, bacteria and archaea already decided the best to use their energy. Every cell continuously judged whether enough ATP was available to build new molecules, or whether scarce resources demanded conservation and repair instead. Early life responded to energy availability, but it did so through many separate, local biochemical sensors rather