Kornkan Chananithitham
Biology - F4

Importance of water to plants and animals

Water is a simple covalent molecule that consists of hydrogen and oxygen atoms. It takes up a quarter of the earth surface, and provides a habitat for the aquatic animals. It is also very important to all living organisms as it is making up 60-95% of the organisms fresh mass. Besides, water has its own special properties that vital to all being, and without it, life could not exist on the planet.

Firstly, water is a good solvent. It means that water allows solute, or solid, to dissolve to form a solution. When the substance is in solution, its molecules can move freely and more reactive than in solid. This is important for both plants and animals because the majority of the reaction in the cells are occur with water or in a liquid state reaction. Moreover, water is also a good transport medium that can carried the substances to all the parts in the plant and animals including in blood vascular system and excretory system.

Secondly, water has a high heat capacity because it require a lot of energy to break its hydrogen bond and high amount of energy to increase its temperature of one kilogram water to one degree celsius. Therefore, the water does not change much in temperature, which help to provide a constant external environment for cells and organisms. For example, the ocean water temperature is tend to be stable, favoring the marine life's environment.

Another importance of water is density and freezing property. Water has maximal density