Question: why does bananas contain potassium?

Ruth Elderfield answered on 15 Jun 2015:

The banana needs potassium in order to grow properly in interacts with the plants enzymes (bits in the plant that do the work) so that it can capture energy from the sun (photosynthesis), burn that energy to build the plant (respiration), move sugars around the plant and to help in the regulation of the amount of water the plant keeps inside or releases to the world (transpiration). When there is plenty of potassium it gets stored along with the energy into the bananas, when there isn’t the plant doesn’t grow very well and you get very few small bananas.