Final answer:
Adding salt creates a hypertonic solution that pulls water out of cells via osmosis, causing the cells to shrivel and potentially become nonfunctional.
Step-by-step explanation:
Adding salt to the mixture in step 4 results in the formation of a hypertonic solution, where the salt concentration outside the cells is higher than the concentration inside the cells. This disparity in solute concentration leads to osmosis, where water is pulled out of the cells to balance the solute concentrations, causing the cells to shrivel. Osmosis is the movement of water across a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration. When the extracellular fluid becomes hypertonic, water moves from the inside of the cell, where it is more pure, to the outside, where it is less pure due to the presence of added solutes like salt. This process is a natural consequence of the cell's attempt to reach equilibrium, but it can lead to cell damage or death as the cell becomes dehydrated and unable to function properly.