system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 What is the chemical process that allows a sinus node in a heart able to produce electricity?

it baffles me that humans can produce electricity, even in such small amounts. i can’t seem to find information online that tells me exactly HOW the electricity is produced in the first place.
gpt
The key to recognize is that we don’t produce electricity the way we do in our power plants…you don’t have conductive wires in your body carrying electrons around. 

Your body used ions…charged atoms. Lots of common materials, e.g. salt, split into a positive and negative ions when they dissolve in water. Special biological structures called ion pumps can selectively push one kind of ion through a membrane and leave the other behind. 

Now you’ve got a concentration of positively charged ions on one side of a barrier and negatively charged one on the other side…we have an electrical potential (a voltage difference). They want to recombine. If we let the ions come back together the voltage difference goes away and we have an electrical pulse, then the ion pumps can restore the potential. It’s creating and releasing these ion potentials that humans (and most other critters) use for electrical signaling.