system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How are my unripe bananas (or any fruit that has been cut off the tree/bush already) less sweet and tastier than my ripe bananas?

If it is no longer getting water and nutrients from the actual plant, how does it continue to get sweeter and tastier by just sitting on my counter?
gpt
A particular hormone called ethylene it causes a chain reaction that breaks complex carbs down into simple sugars, which makes fruits sweeter.  Basically, the pre-existing material is just breaking into sugar.