Cytochrome c

Cytochrome c is a small protein found in the cells of most living organisms, playing a crucial role in energy production. It acts as an electron carrier in the mitochondria, where it helps transfer energy from food to form ATP, the main energy currency of cells. Additionally, cytochrome c is involved in programmed cell death, or apoptosis, which helps remove damaged cells. Due to its essential functions and conservation across species, scientists often use cytochrome c as a marker to study evolutionary relationships among different organisms.