HL IB Biology - Water Properties and Importance

These flashcards cover the key concepts regarding the physical and chemical properties of water, its importance to life, and the origins of water on Earth.

What is the significance of water as a medium for life?

Water is essential for life as it allows chemical reactions to occur, facilitates the movement of dissolved substances, and is involved in metabolic processes.

What role does hydrogen bonding play in biological molecules?

Hydrogen bonding is crucial for the cohesion and adhesion of water molecules, affecting biological processes such as DNA base pairing and protein structure.

How does water’s polarity affect its interactions with other molecules?

Water’s polarity allows it to form hydrogen bonds with polar and charged molecules, making it a universal solvent.

What is the difference between hydrophilic and hydrophobic molecules?

Hydrophilic molecules are 'water-loving' and can form hydrogen bonds with water, while hydrophobic molecules are 'water-hating' and do not interact with water.

What is specific heat capacity and why is it important for water?

Specific heat capacity is the energy required to raise the temperature of 1 kg of water by 1°C. Water's high specific heat capacity helps maintain stable temperatures in aquatic environments.

How does ice's density compare to liquid water and why is this important?

Ice is less dense than liquid water, allowing it to float, which creates an insulating layer that helps maintain stable temperatures in aquatic habitats.

What is the Goldilocks zone in relation to extraterrestrial life?

The Goldilocks zone is the region around a star where temperatures are suitable for water to exist in liquid form, a key requirement for life.

What hypothesis explains the origin of water on Earth?

One hypothesis suggests that Earth's water originated from asteroids and meteorites that contained ice and organic materials.

Explain the concept of capillary action as it relates to water in plants.

Capillary action allows water to move up the xylem in plants due to adhesive forces between water and the polar surfaces of the xylem vessels.

What is the significance of water’s ability to act as a solvent for biological molecules?

Water acts as a universal solvent, allowing for the transport and reaction of various biological molecules essential for life.