It is really very easy to understand. Without water there is no way for the nutrients to enter or the waste products from metabolism to be removed.
Water is the carrier that moves throughthe cell membrane as needed by the cell. It carries nutrients to the mitrochondria and then takes the m-rna to the various locations that need it to make replications of various amino acids or ATP to provide cell energy.
Without water, the cell wall collapses and the cell dies.