Why is water a good transport medium?

Water molecules are also adhesive, meaning they are attracted to other polar molecules and solid surfaces. Due to the interaction of the forces of adhesion and cohesion, water exhibits capillary action. Water rises into a narrow tube against the force of gravity. Water sticks to the inside wall of the tube and surface tension then straightens the surface causing a surface rise and more water is pulled up through cohesion. The process continues as the water flows up the tube until there is enough water so the gravity balances the adhesive force meaning it can efficiently transport substances upwards.

Due to its polarity H2O is also a very good solvent. Substances that will mix well and dissolve in water, like sugar, are known as hydrophilic substances, the love to be in water. Whereas those that do not mix well with water, like oil, are known as hydrophobic substances, which hate to be in water. The ability of a substance to dissolve in water is determined by whether or not the substance can match or better the strong attractive forces that water molecules generate between other water molecules. If a substance has properties that do not allow it to beat these strong intermolecular forces the molecules are pushed away from the water, and do not dissolve. This makes it an excellent solvent for polarised molecules. The electrostatic bonds in water means ions become hydrated in aqueous solution meaning important ions needed for the body can be easily transported through cells by osmosis and won’t join together in a bundle because they dissolve so easily.

Ammonium water has the highest heat capacity ( the amount of heat, measured in joules, required to raise one 1 kg of water by 1 degree C) of all know substances. This means water heats and cools slowly. Without waters specific heat capacity our bodies would vary in temperature a lot, this would make it very difficult for homeostasis in the body as well as altering how effectively water can pass solvents. It also means water stays as a liquid at room temperature, if water wasn’t a liquid it couldn’t transport anything around the body and means there’s no chance it could ever vaporize or freeze within the body.