Chemical and Physical Basis of Life — A/L Biology

A. Water: The Universal Solvent and Medium of Life

Definition: Water is a polar molecule, essential for life, acting as a universal solvent due to its unique hydrogen bonding capabilities and crucial physical properties.

Explanation: Its polarity allows water molecules to form extensive hydrogen bonds with each other and with other polar or charged substances. This gives water properties like cohesion (sticking to itself), adhesion (sticking to other surfaces), high specific heat capacity (resisting temperature changes), and high heat of vaporization, all vital for maintaining life processes and regulating cellular environments.

Think of it as: Think of water as the body's internal delivery truck and cleaning crew, constantly moving nutrients and waste around, while also acting as a thermostat to keep things at the right temperature.