We all heard it in our grade-school science classes: "The mitochondrion is the powerhouse of the cell." And yes, this little organelle — likely the remnant of a bacterium absorbed by early cells millions of years ago — has the crucial job of providing the energy the cell needs. Molecular biologist Vamsi Mootha, who for years has studied mitochondrial biology, will describe how his research has led him to a new understanding of your mitochondrias' fundamental purpose, and discuss what that means for human health.