I described living cells as being crammed full of protein…

““I described living cells as being crammed full of protein molecules. Acting individually or in small assemblies, they perform reiterated molecular processes that can be regarded, I argued, as a form of computation. Moreover, large numbers of proteins linked into huge interacting networks operate, in effect, like circuits of electrical or electronic devices. Networks of this kind are the basis for the animate wanderings of single cells and their ability to choose what to do next. Here I have broadened the view to encompass multiple cells - 'societies' of cells. Through a variety of strategies - including diffusive hormones, electrical signals, and mechanical interactions - the computational networks of individual cells are linked. During evolution, cells acquired the capacity to work together in social groups; it became advantageous for most cells to become highly specialised. Liver cells, muscle cells, skin cells, and so on abandoned their opportunities for unlimited replication. They began the communal expansion of interlinked abilities that led to the plants and animals we see around us today. But the basis of this diversification of cell chemistry was yet another form of computation - one that operates on DNA. Control mechanisms, again based on protein switches, created extensive but subtle modifications of the core genetic information.””

— Dennis Bray