Peter Hegemann and Georg Nagel – awarded the 2026 medicine prize – discovered a remarkable protein, channelrhodopsin, in a single-celled alga. Hegemann wondered how Chlamydomonas, a single-celled alga, is able to swim towards a light source. In the early 2000s, he and Georg Nagel discovered channelrhodopsin, an algal protein with unique properties, found on the surface of the cell. When it is illuminated by blue light, a channel opens through the protein. Charged ions then flow into the cell, creating an electrical impulse. They found that regardless of which cell they put the protein in, those cells became light sensitive. #NobelPrize