Caffeine: What’s in it for the coffee plant?

Ah…that first cup of coffee each day! It almost seems like just the smell of those alkaloids and flavonoids from roasting coffee beans could lift us out of bed in the morning. And that first sip—shared by 26,000 other coffee lovers every second—provides that jolt of caffeine that finally shatters the brittle remnants of last night’s dreams. We owe this pleasurable largesse to the diligent efforts of coffee plants that expend time and energy to transform a precursor compound (xanthosine) into the psychoactive chemical we love and depend upon. Why do those coffee plants do it?