Fighting ageing requires properly equipped cells

A cell’s machinery is made almost entirely of proteins, each of them a chain of amino acids that takes on a particular shape when folded up. The shapes of some of them are designed to recognise other molecules, and sometimes to bring two different molecules together in a way that catalyses a reaction between them. Others are designed to cut DNA, RNA or other protein molecules into chunks. Long thin ones fit together to create the rods and filaments which give the cell structure its cytoskeleton; others make pores in membranes. But whatever has to be done, the protein has to be folded into the correct shape to begin with.