Biology Chapter 1-3 Lecture: Water and Hydrogen Bonds

Flashcards covering key vocabulary, numerical facts, and conceptual definitions regarding the properties of water, hydrogen bonding, and biological applications from Chapters 1 through 3.

Maximum Hydrogen Bonds per Water Molecule

Four (4) bonds total, with each hydrogen forming one bond and the oxygen forming two bonds through its partial negative charges.

Hydrogen Bond Strength in Water

Approximately one twentieth ($\frac{1}{20}$) the strength of a covalent bond, allowing these bonds to easily form, break, and reform in liquid water.

Cohesion

The property of liquid water where water molecules stick to other water molecules via hydrogen bonding, creating surface tension and holding a surface layer together.

Adhesion

The property of water where water molecules adhere to the walls of other surfaces or vessels, aiding in processes like pulling water up plant roots.

Infant Respiratory Distress Syndrome

A disorder in infants where thin alveolar walls collapse and tear due to high water cohesion in the absence of adequate lung surfactant.

Surfactant

A molecule with a charged, hydrophilic head and nonpolar, hydrophobic tails that lines alveolar walls, preventing opposing water layers from attracting and collapsing the lung.

DPPC

The long-named surfactant molecule highlighted in the lecture that regulates the surface tension of water in the alveoli.

Hydrophilic

Water-loving substances that possess a charge or polarity (such as salts, sugars, and ions) and dissolve readily in water.

Hydrophobic

Water-fearing substances that are nonpolar and non-charged (such as hydrocarbons and lipids) and do not dissolve in water.

Solvent

A dissolving agent, such as water, that breaks down a solute to form a solution.

Solute

A substance, such as salt or sugar, that is dissolved by a solvent.

Solution

A homogeneous mixture formed when a solvent completely dissolves a solute.

Sphere of Hydration

A cluster of water molecules (water shell) that surrounds and separates individual dissolved ions based on charge, dissolving the crystal lattice.

Thermal Energy

The total kinetic energy resulting from the movement of atoms or molecules within a body of matter.

Temperature

The measure of the average kinetic energy of the molecules in a body of matter.

Heat

The transfer of thermal energy from a warmer body of matter to a cooler body of matter until thermal equilibrium is reached.

Calorie

The amount of heat energy required to raise the temperature of 1 gram of water by 1 degree Celsius.

Specific Heat

The amount of heat required to raise 1 gram of any given substance by 1 degree Celsius (defined as 1 calorie per gram Celsius for water).

Heat of Vaporization

The quantity of heat required for 1 gram of a liquid to convert into a gas, which occurs at 100 degrees Celsius or 212 degrees Fahrenheit for water.