Water and Its Biological Properties

A set of vocabulary flashcards based on lecture notes regarding the chemical properties, physical characteristics, and biological importance of water.

Polarity

A result of unequal sharing of electrons in covalent bonding, leading to partially positive ($\delta+$) and negative ($\delta-$) charges.

Hydrogen bonding

The attraction that occurs between water molecules due to their polarity.

Cohesion

The attraction between water molecules due to hydrogen bonding, allowing each $H_2O$ molecule to bond with neighboring water molecules.

Transpiration

The process by which water evaporates from leaves through the stomata.

Cohesion-tension theory

The theory explaining how tension, or negative pressure, pulls water upward through the xylem from roots to leaves.

Surface tension

An elastic-like layer at the water's surface caused by molecules being pulled inward by hydrogen bonds, allowing small organisms to walk on it.

Adhesion

The attraction between water molecules and other surfaces, such as the cellulose in cell walls.

Capillary action

The movement of water in narrow spaces against gravity using both adhesion and cohesion.

Hydrophilic

Polar, "water loving" substances that dissolve in water, such as glucose, amino acids, $Na^+$, and $Cl^-$. balance.

Hydrophobic

Non-polar, "water fearing" substances that do not dissolve in water, such as cholesterol, oils, fats, and steroid hormones.

Buoyancy

The upward force exerted by a liquid on an object immersed in it.

Viscosity

A fluid's resistance to flow caused by internal friction; water has high viscosity compared to air.

Thermal conductivity

The rate at which heat transfers through a substance; water has high thermal conductivity compared to air.

Specific heat capacity

The amount of heat required to raise the temperature of $1\,g$ of a substance by $1\,^{\circ}C$.

Asteroids

Celestial bodies that are believed to have delivered water to Earth as ice or hydrated minerals during periods of intense bombardment.

Goldilocks Zone

The region around a star where conditions are right for temperatures to remain liquid, rather than evaporating into vapor or freezing into solid.