Chemicals of Life – Key Vocabulary

Ten vocabulary flashcards covering fundamental terms related to biomolecules, elements, and bonding from the Biology lecture on the chemicals of life.

Biomolecules

Chemical substances that make up living organisms, including both organic and inorganic molecules such as carbohydrates, lipids, proteins, nucleic acids, water, and mineral salts.

Organic Molecules

Large, complex compounds whose structures are based on a backbone of carbon atoms; characteristic of living matter.

Inorganic Molecules

Relatively small, simple molecules that usually lack carbon (or contain very few carbon atoms), e.g., H2O, CO2, O2, NH3.

Element

A pure substance that cannot be broken down into other substances by chemical reactions.

Compound

A substance composed of two or more different elements combined in a fixed ratio, e.g., NaCl or H2O.

Covalent Bond

A chemical bond formed when two atoms share one or more pairs of electrons to fill their valence shells; may be polar or non-polar.

Ionic Bond

A bond produced when one atom transfers electrons to another, creating oppositely charged ions that attract each other (e.g., Na+ and Cl− in NaCl).

Hydrogen Bond

A weak attraction between a hydrogen atom already covalently bonded in a polar molecule and an electronegative atom (such as O or N) in another polar molecule.

Van der Waals Interaction

A weak, temporary attraction between molecules that occurs when fleeting asymmetries in electron distribution create slight opposite charges in adjacent non-polar molecules.

Electronegativity

The tendency of an atom to attract shared electrons in a covalent bond; differences in electronegativity create partial charges, as in the polar bonds of water.