Water quality can be processed in many different ways
A positive potassium cation (K+) could be an example of a solute in the cytosol when it is at its resting potential. To add up, the resting potential difference inside the membranes of a neuron was estimatedly -70 mV wherein aside from potassium ions, sodium ions are also present in the neuron.
I believe group of cells working together and or performing the same task can be categorized also as a specialized tissue.