I think the molecular structure is very similar to a necessary molecule (fat or sth.?). So the PFAS get in the place a normal molecule should be but they do the job not as good. Something like that. Great MinuteEarth Video about PFAS (4’) https://www.youtube.com/watch?v=H3aFzQdWQTg
Its about ~2-3GB for a movie for me. The Quality isnt great but still better than Netflix streams.