(285) A1.1 Properties of Water [IB Biology SL/HL]

Properties of Water

• Water is a crucial compound on Earth and mostly exists in a liquid state at various temperatures, allowing it to participate in numerous biochemical processes.

• The majority of metabolic reactions in cells occur with molecules dissolved in water, highlighting its importance in biological systems.

Structure of Water Molecule

Composition

• A water molecule is composed of two hydrogen atoms and one oxygen atom, represented chemically as H2O.

Chemical Bonds

• The atoms in water are linked by a covalent bond, which indicates that they share electrons.

• In water, there is an unequal sharing of electrons between oxygen and hydrogen atoms due to oxygen's higher electronegativity, resulting in a polar molecule.

Importance of Water's Properties

• The unique properties of water, arising from its molecular structure, facilitate life by enabling essential biochemical reactions.