The Biological Importance of Water as a Solvent and as a Medium for Living Organisms

The Biological Importance of Water as a Solvent and as a Medium for Living Organisms

Water is possibly the most important substance life as we know it, as

we need in order to survive; it also provides an environment for many

species. All cells contain a minimum of 85% of water, with most fluids

inside and outside of the cell likely to have at least 90% water. Both

transportation of molecules and chemical reactions take place in

dissolved water.

In chemical terms, the water molecule is strongly dipolar, this

property makes water a very effective solvent, particularly for

crystalline salts .So, water is the solvent of the body & it regulates

all functions, including the activity of everything it dissolves &

circulates.

When we look at a molecule of water, we know that the hydrogen

molecules carry a small positive charge and the single oxygen carries

a negative charge, because the molecules are charged, it makes water a

polar molecule. The fact that water is a polar molecule is very

important to many of its properties.

When water molecules join together, the two different charges have an

effect. Two opposite charges attract, so the negative charges of the

oxygen’s, are attracted to the positive charges of the hydrogen’s,

this causes a strong bond, known as a hydrogen bond.

Hydrogen bonds stick to each other, i.e. they are Cohesive, and this

cohesion holds the molecules together when they move, meaning that

water and dissolved substances can be moved in a cell with ease, these

dissolved substances and water are moved around organisms via these

transport systems.

Not only is water an important solvent, but it is also an essential

medium for living organisms. It is important in two ways-

· It is essential for survival

· It provides an environment for many species.

In terms of survival, water does 2 important things. It acts as a

supporter, and a heat holder. As water stays as a liquid at the

temperature and pressure that organisms live at, increasing the