Chapter 2: The Chemical Foundation of Life

Vocabulary practice flashcards generated from Biology Chapter 2 lecture notes covering basic chemistry concepts, water properties, pH, and organic carbon compounds.

Protons

Positively charged particles ($p^+$) located within the nucleus of an atom.

Neutrons

Neutral particles ($n^0$) located within the nucleus of an atom.

Electrons

Negatively charged particles ($e^-$) located in shells surrounding the nucleus.

Mass number

The total number of protons plus the number of neutrons in an atom.

Atomic number

The total number of protons in an atom.

Isotopes

Forms of an atom that have different numbers of neutrons.

Octet rule

The principle that atoms tend to gain, lose, or share electrons with other atoms in order to achieve a total of 8 electrons in their valence shell.

Valence shell

The outermost electron shell of an atom.

Chemical reaction

The process of making or breaking chemical bonds.

Reactants

The initial chemicals that enter into a chemical reaction.

Products

The resulting chemicals produced by a chemical reaction.

Ionic bond

A chemical bond formed when electrons are transferred from one atom to another.

Cation

A positively charged ion formed when an atom loses an electron.

Anion

A negatively charged ion formed when an atom gains an electron.

Polar covalent bond

A covalent bond formed when atoms share electrons unequally, creating partial charges on the atoms.

Nonpolar covalent bond

A covalent bond formed when atoms share electrons equally.

Hydrophilic

Refers to molecules that are attracted to water.

Hydrophobic

Refers to nonpolar molecules that are not attracted to water and do not dissolve in it.

Heat capacity

The amount of heat required to change the temperature of a substance by $1,^\text{o}\text{C}$.

Heat of vaporization

The amount of energy required to change a substance from a liquid to a gas state.

Solvent

The liquid in a solution that dissolves other molecules or solutes.

Solute

A substance that is dissolved by a solvent to form a solution.

Solution

A liquid mixture composed of a solvent and dissolved solutes.

Cohesion

The ability of water molecules to stay together due to hydrogen bonding.

Surface tension

The ability of a liquid's surface to resist breaking when placed under tension.

Adhesion

The attraction between water molecules and other types of molecules.

pH

A scale used to specify the acidity or basicity (alkalinity) of a solution, calculated as $\text{pH} = -\text{log}[\text{H}^+]$.

Acid

A proton donor that increases the $\text{H}^+$ concentration in a solution, resulting in a pH lower than 7.

Base

A proton acceptor that removes $\text{H}^+$ from a solution, resulting in a pH greater than 7.

Buffers

Compounds that minimize changes in pH by binding or releasing $\text{H}^+$ ions.

Organic molecules

Molecules that contain carbon atoms in their molecular structure.

Hydrocarbons

Organic molecules consisting entirely of carbon and hydrogen atoms.

Aliphatic hydrocarbons

Hydrocarbons that consist of linear chains of carbon atoms.

Aromatic hydrocarbons

Hydrocarbons that consist of closed ring structures of carbon atoms.

Functional group

A group of atoms attached to a carbon backbone that exhibits a specific chemical function.