Module 2: Chemistry of Life Review

Vocabulary review covering atomic architecture, chemical reactions, enzymes, properties of water, and biological macromolecules.

Atom

The building block of matter which contains subatomic particles.

Proton

A positively charged particle located in an atom's nucleus.

Neutron

A particle without an electrical charge located in an atom's nucleus.

Electron

A negatively charged particle that occupies the space around an atom's nucleus and is responsible for forming chemical bonds.

Isotope

Two or more atoms of the same element that have different numbers of neutrons.

Compound

A pure substance formed when two or more different elements combine.

Molecule

A compound whose atoms are held together by covalent bonds.

Ion

An atom that is negatively or positively charged because it has lost or gained one or more electrons.

Covalent Bond

A type of chemical bond formed when atoms share electrons.

Ionic Bond

An electrical attraction between two oppositely charged atoms or groups of atoms.

Reactant

The starting substance or molecule that interacts in a chemical reaction, shown on the left side of a chemical equation.

Product

The substance or molecule formed from a chemical reaction, shown on the right side of a chemical equation.

Enzyme

A special protein that acts as a biological catalyst to speed up chemical reactions by lowering the activation energy barrier.

Polar Molecule

A molecule that has an uneven distribution of charges, resulting in oppositely charged regions.

Hydrogen Bond

A weak interaction involving a hydrogen atom and an oxygen, fluorine, or nitrogen atom.

Cohesion

The attraction of water molecules to each other due to polarity, which creates surface tension.

Adhesion

The property where water molecules are attracted to other molecules on surfaces.

Solution

A homogeneous mixture formed when a substance (the solute) is dissolved in another substance (the solvent).

Acid

A substance that releases hydrogen ions.

Base

A substance that releases hydroxide ions.

pH

A measure of the concentration of hydrogen ions in a solution.

Buffer

A mixture that reacts with an acid or a base to maintain the pH of a solution within a specific range, such as keeping human blood strictly regulated at a pH of $7.4$.

Carbohydrate

An organic compound containing carbon, hydrogen, and oxygen in a ratio of one oxygen and two hydrogen atoms for each carbon atom, serving as a central energy source in organisms.

Lipid

A hydrophobic biological molecule composed mostly of carbon and hydrogen that makes up fats, oils, and waxes.

Protein

An organic compound made of amino acids joined by peptide bonds that serves as a primary building block of organisms and is involved in nearly every bodily function.

Amino Acid

The monomer from which proteins are built, always containing carbon and oxygen.

Nucleic Acid

A complex macromolecule that stores and communicates genetic information.

Peptide Bond

The chemical bond that joins amino acids together to form proteins.