Importance of Water to Living Organisms

by Debashree Sen; Updated September 26, 2017

Water is one of the main constituents on earth. Two thirds of the earth is covered by water. Approximately 75 percent of the human body is formed of water. Every form of life on earth depends on water in one form or other for its subsistence. In human beings, water helps with transporting and replenishing nutrients. It helps with cleansing the human body. Water bodies like sea, lakes and ponds are home to thousands of creatures.


Metabolism is defined as the process that cells of living organisms execute to generate energy to carry out vital activities. This energy generated from metabolism is used for growth and maintaining daily processes. Water is the medium used by the human body to carry out various chemical reactions. It is essential for moving oxygen, nutrients and hormones through the blood stream. Water thus helps with the basic metabolism of the human body by facilitating the chemical reactions that take place in the human body.


Water is the solvent for chemical reactions in the human body. It has a unique chemical formation that helps it to dissolve a wide variety of molecules (like salts). The hydrogen atoms of water (positively charged) attract negatively charged atoms of the particles it dissolves and oxygen atoms of water (negatively charged) attract the positively charged atoms of the particles. Other compounds like sugars, proteins and amino acids, which are polar (having a positive and a negative component like salts), also dissolve in water. However compounds such as oils and fats that are non-polar do not dissolve in water.

Temperature Moderator

A number of chemical reactions take place within human cells that produce energy to be used by human beings. Enzymes catalyze a majority of these reactions. These enzymes need a specific range of temperature to act optimally. Water helps with keeping the range of temperature in the human body moderate for these enzymes to act properly. This helps with the process of metabolism in the human beings.


Photosynthesis is a process that is employed by plants to produce food (sugar). This process uses sunlight, green pigment chlorophyll and water. The process produces oxygen, which forms the basis of life in this planet. Some forms of bacteria also exhibit photosynthesis, which utilizes water in the process.


Water provides habitat to a thousands of creatures. The oceans are home to fish, otters, turtles, sharks and dolphins. There are plenty of microorganisms that live in water. Ducks, beavers and frogs live in ponds.

About the Author

Debashree Sen is a technical writer and has written for non-profit organizations. She has been regularly contributing to eHow since 2009. She is a member of the Society for Technical Communication (STC). She has a master's degrees in professional writing and English literature.

Photo Credits

  • Sea coast, the beautiful colors sea water image by Supertrooper from