Question

19. Water that contain a huge range of biochemical pathways? has such a high boiling point and is a major component of cells. How does this impact cells

Answer 1

The water impacts the biological pathways in the following ways: 1. Water plays a key role in chemical reactions like hydrolysis, condensation etc that involve removal and addition of water. It also plays a key role is light dependant photosynthetic reactions. 2. It acts as an important solvent dissolving all hydrophillic substances in itself. Thee proteins and enzymes in our body function more efficiently in solutions of low viscosity 3. Due to high heat capacity, it stores heat energy. This stabalises the temperature of the body in cold environments. 4. It has high latent heat of vapourisation because of which it help body cool by sweating. The thermal energy generated by the body is used to evaporate the sweat which in turn cools the body down. 5. It moves nutrients, hormones, antibodies and oxygen through the blood stream and lymphatic system acting as a medium of transport.

6. Water contributes to buffering changes in pH in organisms. It combines with CO2 to form carbonic acid which dissociated into hydrogen ion and bicarbonate ion. If the pH increases the carbon dioxide and water react to form carbonic acid which, in turn, dissociates to release hydrogen ions, which decrease the pH, and bicarbonate6. The reverse occurs for a decrease in pH 7. Water plays a role in respiration; it cleaves a phosphate off ATP, energy currency of cells, to give ADP and energy for respiration 8. Water is produced in oxidative phosphorylation. The formation of water allows the process to continue; if water didn't form then cell death would follow. Ex Cyanide inhibits the formation of water from oxidative phosphorylation