CARERI LECTURES

by Prof. Dennis Bray

Tuesday 10 May 2011, 16:00 → 19:00 Europe/Rome

Aula Conversi (Dipartimento di Fisica - Ed: G. Marconi)

PROTEIN COMPUTATIONS AND THE ORIGINS OF BEHAVIOUR Cells are built up of molecular circuits that perform logical operations, analogous in many ways to electronic devices but with unique properties. The computational units of life are its giant molecules, especially proteins. These act like miniature transistors to guide the biochemical processes of a cell and, linked into huge networks, they form the basis of all of the distinctive properties of living systems. Molecular computations underlie the sophisticated decision making of single-cell organisms such as amoebae. Protein complexes associated with DNA act like microchips to switch genes on and off in different cells – executing ‘programs’ of development. However, as illustrated by our work on bacterial chemotaxis, the simple form of behaviour in which bacteria smell and swim towards distant sources of food, living circuitry differs in fundamental respects to silicon devices. It has unique features such as a highly malleable internal architecture and an existence of a multitude of molecular states that we cannot yet reproduce. The chemical states of a cell encode its past experiences and allow it to anticipate future conditions. Predictions underlie the goal-oriented movements of all animals, even single cells, and form the basis of brain function in humans.