Focus on water's characteristics and their importance to humans.
Water is vital for all living organisms but this lecture centers on its role in human life.
Basic Structure of Water
Water is composed of two hydrogen atoms and one oxygen atom held together by covalent bonds.
Hydrogen atoms have a partially positive charge, while the oxygen atom has a partially negative charge.
Water molecules form hydrogen bonds with each other due to these charges.
Importance of Hydrogen Bonds
Hydrogen bonds enable water molecules to adhere to each other.
These bonds are integral to many of water's properties that benefit humans.
Water as a Solvent
Water constitutes 50% of blood, which is crucial for transporting substances necessary for life.
Plasma, part of blood, is mostly water and carries dissolved substances such as glucose, amino acids, and salts.
Water is known as a "universal solvent" because it dissolves many polar substances (hydrophilic).
This property allows water to transport dissolved substances wherever it flows.
High Specific Heat Capacity
Water requires a large amount of heat to raise its temperature by 1°C due to hydrogen bonds.
This property means water's temperature remains stable, which is beneficial for maintaining homeostasis in living organisms.
Example: A person's body temperature remains stable (37°C) even when moving between different temperatures (e.g., from a cold room to the hot sun).
Aquatic environments remain stable, supporting life therein.
High Latent Heat of Vaporization
Water requires a lot of energy to change from liquid to vapor, known as its high latent heat of vaporization.
This property allows water to absorb significant heat from the body before evaporating, aiding in cooling.
Example: Sweat cools the body efficiently because water absorbs a lot of heat before turning into vapor.
Conclusion
Water's characteristics make it indispensable for life due to its role as a solvent, its ability to maintain stable temperatures, and its efficiency in cooling.
The hydrogen bonds in water are crucial to these properties, supporting life by enabling water to act as a transport medium, temperature stabilizer, and coolant.