The Role of Water in the Lives of Organisms Essay -- Biology Essays

The Role of Water in the Lives of Organisms Water is perhaps the most important molecule for the survival and life of all living organisms because there is a wide spectrum of roles that it plays. The fact that the earth's surface consists of 70.8% water shows its significance and importance. ====================================================================== Firstly, water has the chemical formula Hg0 (two Hydrogen atoms to one Oxygen atom), the covalent bonds between which create cohesive forces. Water has a very high specific heat capacity, measuring 4,200 Joules, creating a stable environment for organisms to live in. This means that water does not heat up or cool down too rapidly due to the difficulty in breaking the hydrogen bonds, which restricts the movement of the water molecules. This property of water is beneficial to aquatic organisms (e.g. Fish, Jellyfish), as they do not have to keep adapting their own body temperatures for survival. Another property water has is its insulating nature in lakes and rivers. As water cools toward 0Â °C, the water molecules slow down to form the maximum number of hydrogen bonds. As this process continues, water molecules must give enough space for all four hydrogen bonds to fit, causing the water to expand as it freezes to form ice. Ice is less dense than the liquid form and therefore floats, a property very significant to the survival of fish as this layer of ice insulates the liquid water below to prevent the whole lake or river to freeze. Otherwise, this could be fatal for many organisms in the aquatic food web. Aquatic plants can survive in deep waters due to the fact th... ...er as sweat, the liquid gets turned into a vapour causing humans to cool down and control our body temperature (a homeostasis process). The cooling functions of water are connected to its high heat capacity nature. Water has influences on a large number of aspects of organisms' lives'. From habitat, transport, support, movement, fertilisation, insulator, roles of key processes (photosynthesis and respiration), protection from damage, homeostasis and gas exchange. Enzymes are very important in the body of some / most organisms and catalyse almost every reaction. However, they are soluble and will need water to function, as a result water is very important. Water is an important substrate for chemical reactions as well as product. Around 70% of human mass consists of water, in plants, 95% of mass consists of water.