K+ transport is when an imbalance of k+ in a cell occurs in the sense of +/-. k+ is positive but proteins are negative lowering the total charge. Outside the cell there's salt which has more charge. Certain chambers will open in the cell to allow a transfer sort of like osmosis!
It's been a while so I hope I didn't mess anything up. A good guy explained this on his YouTube page, his name is BozemanBiology on youtube