Scientists at Michigan State University have uncovered the molecular “switch” that powers sperm for their final, high-speed dash toward an egg. By tracking how sperm use glucose as fuel, the team discovered how dormant cells suddenly flip into overdrive, burning energy in a carefully controlled, multi-step process. A key enzyme, aldolase, helps convert sugar into the burst of power needed for fertilization, while other enzymes act like traffic controllers directing the flow of fuel.