Chapter 4 — Chapter 4 — Molecular Biology

Water (H₂O) is polar: O is partially negative, H partially positive; molecules form hydrogen bonds and stick together (cohesion) — the basis of most unique properties. Properties: universal solvent (dissolves ions and polar molecules), high specific heat (4.2 J g⁻¹ °C⁻¹ — stabilizes temperature), high heat of vaporization (cooling by sweating/transpiration), cohesion and adhesion (capillarity, xylem transport), high surface tension, ice less dense than water (floats, insulates aquatic life), transparency, participates in hydrolysis and photosynthesis. Forms 60–90% of living matter.