Biological Importance and Properties of Water

Vocabulary terms and definitions focusing on the chemical structure, physical properties, and biological importance of water based on the lecture transcript.

Body Water Composition

The human body is made up of approximately $60\%$ water.

Blood Water Composition

A majority of blood is composed of water, specifically $90\%$.

Polar Covalent Bond

A strong bond within a single water molecule formed by the unequal sharing of valence electrons between oxygen and hydrogen.

Dipole

A term describing a molecule like water that has two polarities, with oxygen being partially negative and hydrogens being partially positive.

Hydrogen Bond

A weak bond or attraction between two separate water molecules, often represented by dashed lines.

Homogeneous Mixture

A mixture that looks the same throughout, such as a solution made of two or more parts.

Solvent

The part of a solution that does the dissolving; water is known as the universal version because it can break many things apart.

Solute

The substance in a solution that is dissolved by the solvent, such as salt ($NaCl$).

Hydrophilic

Derived from root words meaning 'water-loving', referring to substances that dissolve in water.

Hydrophobic

Derived from root words meaning 'water-fearing', referring to substances like oil that do not dissolve or mix with water.

Saturated

A point where a solution is completely filled and no more solute can be dissolved because all water molecules are used up.

Adhesion

A property of water where molecules stick to other surfaces, such as the sides of blood vessels or plant stems.

Cohesion

A property of water where molecules stick together to one another.

Surface Tension

A surface effect created by hydrogen bonds that allows certain organisms or objects to float on top of water.

High Heat Capacity

The ability of water to store or absorb a large amount of energy before its temperature changes, which is vital for homeostasis.

Homeostasis

The maintenance of a stable internal environment, such as keeping the human body temperature at $37^\circ C$.

Low Density Solid State

The property that allows ice to be less dense than liquid water, causing it to float and act as an insulator for ecosystems below.