Chapter 2: The Chemistry of Life

These flashcards cover essential vocabulary and key concepts from Chapter 2: The Chemistry of Life, including definitions of terms related to atoms, chemical reactions, and macromolecules.

Atom

The basic unit of matter; the smallest fragment of any substance.

Nucleus

The center of an atom, containing protons and neutrons.

Electron

A negatively charged particle that orbits around an atom's nucleus.

Element

A pure substance that consists entirely of one type of atom.

Isotope

Atoms of the same element that differ in the number of neutrons.

Compound

A substance formed by the chemical combination of two or more elements in definite proportions.

Ionic Bond

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

Ion

An atom or molecule that has a net electric charge due to the loss or gain of one or more electrons.

Covalent Bond

A chemical bond formed when two atoms share electrons.

Molecule

The smallest unit of most compounds, formed when atoms are joined by covalent bonds.

Van der Waals Forces

Weak attractions between molecules or parts of molecules that result from transient local partial charges.

Hydrogen Bond

A weak bond formed between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.

Cohesion

The attraction between molecules of the same substance.

Adhesion

The attraction between molecules of different substances.

Solution

A mixture in which one substance (the solute) is dissolved in another (the solvent).

Suspension

A mixture of water and non-dissolved materials that remains suspended.

Acid

A compound that releases hydrogen ions (H+) in solution.

Base

A compound that produces hydroxide ions (OH−) in solution.

Buffer

Weak acids or bases that can react with strong acids or bases to prevent sharp changes in pH.

Macromolecule

Large organic molecules, such as carbohydrates, proteins, lipids, and nucleic acids, essential for life.

Monomer

The smaller unit that joins together to form a polymer.

Polymer

Large compound formed from combinations of many monomers.

Activation Energy

The energy needed to start a chemical reaction.

Enzyme

A biological catalyst that speeds up chemical reactions in living organisms.

Substrate

The reactant on which an enzyme works.

Chemical Reaction

A process that changes one set of compounds into another.

Reactant

The elements or compounds that engage in a chemical reaction.

Product

The elements or compounds produced by a chemical reaction.

Trace Elements

Elements required by an organism in only minute quantities.

Polar Molecule

A molecule with uneven distribution of charges; one end has a partial positive charge and the other end has a partial negative charge.

Hydrophobic

Substances that fear water; they do not mix with water.

Hydrophilic

Substances that are attracted to water.