Okay kiddo, let me explain the GHK flux equation in a way you can understand.
Imagine you have a bunch of tiny doors in a wall. Each door has a keyhole that only fits certain keys, and there are different types of keys that fit into the different keyholes. When a key fits into a keyhole, it opens the door and allows things to move in and out.
Now, let's say there are little balls that want to move through the doors to get from one side of the wall to the other. Some balls are positively charged, and some are negatively charged. The balls are attracted to the doors with keyholes that fit their keys, and different types of keys fit into doors with different charges.
The GHK flux equation is like a formula that tells us how many balls will go through each door, depending on how many balls there are, the charge on the balls, the charge on the doors, and other factors.
It's like a puzzle that helps us figure out how things move through tiny openings, which can be really useful for understanding how ions move through membranes in cells, or how medications get into our bodies.
So, that's the GHK flux equation explained like you're five!