The photosynthetic electron transport chain of cyanobacteria and chloroplasts catalyses the conversion of solar light into chemical energy, which in turn serves as the primary source of energy for most of the Earth’s ecosystems. Central to this process are photosynthetic electron carrier proteins. Photosystem I, a key photosynthetic enzyme, is capable of accepting electrons from two evolutionarily distinct photosynthetic electron carriers: the blue copper protein plastocyanin and the haem-containing protein cytochrome c6. Whilst it has been postulated that cytochrome c6 (which is absent in plants) is the more ancient of the two proteins, recent bioinformatic evidence has refuted that claim. In this project, state-of-the-art electrochemical techniques will be used to analyse and compare the electron transfer kinetics of plastocyanin and cytochrome c6. The first period of the project will involve training in molecular biology and protein purification with the rest of the project focussing on electrochemistry and computational analysis. This is an exciting opportunity for an enthusiastic student to be at the vanguard of a project answering fundamental scientific questions about how life as we know it came to be. Students will be expected to present their findings orally at a research day in York in September 2024.