What is a Q-V curve? What is its importance in biomembranes?

As the title suggests, I’m not sure what a Q-V curve measures exactly. It’s mentioned in a biology paper I’m reading for school but it doesn’t give a definition of what it means. The paper is entitled Removal of phospho-head groups of membrane lipids immobilizes voltage sensors of K+ channels

Any information would be greatly appreciated!

I just looked a bit without going to deeply, but I think its similar to an ECG showing the depolarization of the cell membranes plotted over time.

An ECG has similar type letters used for different aspects of a heartbeat ‘graph’

Can’t be very specific without seeing the paper, but a Q-V curve is a plot of charge against voltage measured on a patch of cell membrane. Read this and follow up.