system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 what happens when you knead bread dough

I understand that it strengthens the dough, but how does this happen? How much kneading is "too much," and what happens to the dough at this point?
gpt
By kneading together your dough, you're making gliadin and glutelin combine into gluten.  Gluten is elastic and springy.  It's this elastic property that allows the dough to catch the gasses produced by the yeast/baking powder/baking soda/leavening, blowing bubbles.

If you overknead the dough, the gluten gets too strong and the leavening can't raise the bread, so it just gets hard and dense.