system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: how do LED grow lights replicate the sun when growing plants . how does photosynthesis and respiration happen?
gpt
Photosynthesis is just a chemical reaction (or more accurately, a super complicated chain of chemical reactions) that get activated when certain chemicals absorb certain frequencies of light. 

We can manufacture LEDs that send out those frequencies of light, so they trigger the reactions, allowing plants to photosynthesize.