Water is an essential biomedical molecules consisting of one atom of oxygen and two atoms of hydrogen, joined together by covalent bond. Covalent bonds are bonds formed as a result of sharing electrons. Water molecules are joined together by hydrogen bond. Hydrogen bond is an electrostatic force of attraction between highly electronegative atom like oxygen and a hydrogen atom.
Hydrogen bonds that exist between water molecules are formed as a result of an uneven distribution of electron density between the atoms. The oxygen has an unshared pairs of electrons which makes it partially negative and the hydrogen atom partially positive; these then attract to form hydrogen bond. Water is therefore a polar molecule.
Water is essential for two main reasons. Firstly, it is the major component of cell, 70 – 75 percentage of cell mass. And secondly, it provides an environment for organisms that live in water. Ie. ¾ of the earth is water.
Water has got many properties which relates to its biological functions. Noticeable among them includes the following;
Water has solvent properties. It is an excellent solvent for many compounds. Some compounds such as sugar and glycerol dissolve in it as molecule whiles others called electrolytes (nacl) dissociate and dissolve not as neutral molecules but as charged species called ions. This is due to the polar nature of water molecule carries a slightly positive charge whiles the oxygen side carries a slightly negative charge.
These solvent properties of water are vital in biology because many biochemical reactions take place only within aqueous solution. Example is hydrolysis reaction involving carbohydrate and protein to yield glucose and amino acid respectively for cell absorption. Water is also use to transport biological molecules. Example is the removal of metabolic waste such as urea and ammonia in urine.
The thermal properties of water are also link to its hydrogen bond. This bond restricts the movement of water...