D: And you're wondering what gives.

Y: Right. It was a good banana yesterday. What happened?

D: It's no mystery, Yael. Those spots are a natural part of the ripening process. You see, just like all fresh produce, your bananas are alive. They're taking in oxygen to   help them convert sugars into energy, and releasing carbon dioxide. This process is called respiration.

Y: I don't know, Don, this banana looks dead to me.

D: Now, the quicker a fruit or vegetable respires, the quicker it ripens. For most fruits,the respiration rate slows down after the initial growth stage and the fruit ripens slowly. The growth and ripening process of bananas, however, is different. Although  at first the banana's respiration slows down too, when it's ready to ripen, the   banana's pulp releases a chemical that increases respiration. This converts the starches in the banana to sugars and gives it its fabulous taste. And you know how good bananas taste!

Y: Watch it--you're drooling. But what does all this ripening have to do with spots?

D: Well, with all this respiration, the banana eventually processes all the starches available. And that's when it begins to die. Those brown spots are rot and decay.

Y: Poor thing. It just ran out of fuel.

D: Yeah, it's never easy seeing a good banana go bad.