Water Flashcards
(8 cards)
What are the key properties of water?
Important metabolite, important solvent, high specific heat capacity, large latent heat of vaporisation, cohesion and adhesion.
What is the importance of water as a metabolite?
Many metabolic reactions are either condensation or hydrolysis reactions (e.g. condensation of amino acids to form a polypeptide, or hydrolysis of disaccharides to monosaccharides).
What is the importance of water as a solvent?
Water is a polar molecule and can therefore interact with other charged ions or polar molecules. Many ions and molecules can dissolve in it, so it is a good solvent. All metabolites are aqueous, so cells are the perfect environment for metabolic reactions, as they’re water-based.
What is the importance of the high specific heat capacity of water?
Due to hydrogen bonding, it takes a lot of energy to change the temperature of water, so water has a high specific heat capacity.
Therefore, water doesn’t experience rapid changes in temperature and acts as a buffer to sudden temperature changes. This means that aquatic organisms can live in a thermally-stable environment and their enzymes can stay at optimum temperature, and that terrestrial organisms can resist temperature fluctuations and maintain a constant body temperature.
What is the importance of the large latent heat of vaporisation of water?
It takes a lot of energy to break Hydrogen bonds and change liquid water into a gas making water a good coolant in organisms that perspire without losing too much water.
What is the importance of cohesion of water?
Cohesion is when water forms Hydrogen bonds with itself. Cohesion allows water to flow, aiding the transpiration stream in plants, where water pulls more water through the xylem as it moves as a continuous column, this is great for transporting substances.
What is the importance of adhesion of water?
Adhesion is when water forms Hydrogen bonds with other materials.
What is surface tension formed by water and what is its importance?
Due to cohesion, water creates surface tension when in contact with air. This means that sweat forms droplets which can evaporate to cool an organism down.
Surface tension also allows insects such as pond skaters to move on the surface of water, which provides a good habitat for such insects.
