system
Given the following post, respond as if you're commenting on Reddit:
human
eli5, what is in our spit that can break oil apart?

If I were cooking and got butter on my finger and then try to wash it off, the butter just spreads around. 
But if I were to lick or suck the butter off my finger, it's gone immediately without a trace. Why? Is it something in our spit? Or is the surface of our tongue? Both? Thanks!
gpt
Saliva contains enzymes like amylase and lipase. These enzymes act a lot like soap. One side of the molecule attaches to the oil molecule and the other is attracted to water allowing oil to be broken up in water more easily. Aka as emulsification. 

Fun fact: some conservators (painting restorers) use artificial human saliva as a cleaning agent to remove the grime on some paintings.