system
Given the following post, respond as if you're commenting on Reddit:
human
Is sugar content higher in ripe vs. unripe fruit?

You have two bananas, one ripe, one green and unripe. The ripe banana will taste sweeter, leading me to believe it has more sugar, but I would assume both bananas have the same total calories.
gpt
In the case of bananas, commercially produced bananas are almost always treated with ethylene gas which acts as a plant hormone that helps the fruit ripen (it's also responsible for the yellow colour). When this happens, enzymes in the fruit convert starch to sugar, which makes it taste sweeter and also makes the fruit softer. 

So yes, the calories are the same, but the way you absorb and metabolize them will be different (starches vs. sugars).

Essentially ripening is a process where the walls of the fruit cells break down into various water-soluble sugars which makes the fruit squishier and sweeter.