Scientists have made a breakthrough in understanding how mitochondria - the "powerhouses" of human cells - are made. Mitochondria, which exist within human cells but have their own DNA, need many different proteins to function - but the process of how they get these has never been imaged in detail. Now a study led by Dr Vicki Gold, of the University of Exeter, has shown that some ribosomes - the tiny factories of cells which produce proteins - are attached to mitochondria. This can explain how proteins are pushed into mitochondria whilst they are being made. The findings open new avenues for studying protein targeting and mitochondrial dysfunction, which has been implicated in diseases including