Valentine’s Day is Saturday, and people will be spending billions on their sweethearts. Much of that cash will be dropped on sweet-smelling roses. But did you know that one minor chemical change would make that rose not smell as sweet? Chemist Raychelle Burks, Ph.D., explains why in the debut episode of our new sub-series Get to Know a Molecule (GTKAM). Check out future GTKAM episodes every 2 weeks, where we'll highlight more everyday compounds from the 91 million molecules scientists have uncovered.