The biological importance of water
All life on earth requires water to survive.
All living cells contain over 70% water!
Organisms use water in a number of different ways:
- Temperature control. Water slows down changes in temperature. This helps maintain an optimal temperature for enzymes.
- Solvent. Most reactions in the cell require the reactants to be in a water-based solution.
- Transport medium. Both animals and plants use water-based solutions to transport substances around the organism.
Blood is roughly 83% water. Blood transports ions, hormones and digested food around the body.
In plants, water transports mineral salts through xylem vessels.
Plants have additional uses for water. Water is a reactant in photosynthesis reactions. It is also used to maintain the turgidity (stiffness) of cells that keeps plants upright.