Role of Water in the Origin of Life:
Following unique features of water make it the most suitable medium for the origin of life-
- Water remains in liquid form between 4°C-90°C and life also sustains this range of temperature.
- Water is a stable compound and does not decompose easily. Hence it forms a suitable medium for chemical reactions.
- Water is a good solvent for most of the substances that occur in living organisms.
- Several chemicals become reactive only when dissolved in water.
- Water is the source of molecular oxygen and hydrogen ions in living cells.
- Because of its high latent heat, water does not allow quick changes in the body temperature of organisms. It, thus, protects organisms from thermal shocks.
- Proteins and nucleic acids attain their three-dimensional structure only in the presence of water.
- Lipids form bilayers in contact with water. It is basic to production of cell membranes.
- It helps in breaking complex substances through hydrolytic splitting. The phenomenon is called dehydration synthesis.
Water expands on freezing and becomes lighter, floating as a sheet of ice on water.
Floating ice does not allow the underneath water to get frozen. In this way it protects the deep lying plants and animals from low temperature.
