Module 2: Cell Chemistry

Vocabulary flashcards covering matter, energy, reactions, water, pH, and macromolecules.

Matter

Anything that occupies space and has mass; the substance of the universe, composed of one or more elements.

Element

A pure substance that cannot be created or broken down by chemical means.

Atom

The smallest unit of an element that retains its properties; composed of protons, neutrons, and electrons.

Proton

A positively charged subatomic particle located in the nucleus.

Neutron

An electrically neutral subatomic particle located in the nucleus.

Electron

A negatively charged subatomic particle orbiting the nucleus; major role in chemical bonding.

Atomic Number

The number of protons in the nucleus; defines the element and, in a neutral atom, equals the number of electrons.

Isotope

Atoms of the same element with the same number of protons but different numbers of neutrons.

Radioactive Isotope

An unstable isotope that decays and emits particles and energy; used in medical imaging and treatment.

Ion

An atom with a net electrical charge (positive or negative).

Cation

A positively charged ion.

Anion

A negatively charged ion.

Molecule

Two or more atoms held together by chemical bonds.

Compound

A substance composed of two or more different elements bonded together.

Ionic Bond

A bond formed by the attraction between oppositely charged ions.

Ionic Compound

A compound formed from cations and anions held together by ionic bonds.

Valence Electrons

Outermost electrons involved in chemical reactions and bonding; determine an element’s bonding behavior.

Kinetic Energy

Energy of motion.

Potential Energy

Energy due to position; includes chemical energy stored in bonds.

Chemical Reaction

A process where atoms/molecules interact to form new substances; involves reactants and products; may be sped by catalysts.

Catalyst

A substance that speeds up a chemical reaction without being consumed.

Enzyme

A protein that acts as a biochemical catalyst in living systems; reactions occur on the enzyme with substrates.

Substrate

A substance that undergoes a chemical reaction in the presence of an enzyme.

Water

Essential to life; about 70% of the body; a polar solvent that dissolves polar solutes and facilitates bodily functions.

Solvent

The dissolving medium in a solution.

Polar

A molecule with charged regions; dissolves in polar solvents.

Nonpolar

A molecule lacking charged regions; tends to dissolve in nonpolar solvents.

Like Dissolves Like

Rule that polar solutes dissolve in polar solvents and nonpolar solutes in nonpolar solvents.

pH

A scale (0-14) measuring the concentration of hydrogen ions in solution.

Buffer

A mixture of weak acids and weak bases that helps maintain a constant pH range.

Acid

A substance that releases H+ ions into solution.

Base

A substance that releases OH- ions or accepts H+ in solution.

Macromolecule

A large biological polymer (carbohydrates, lipids, proteins, nucleic acids) built from monomer subunits.

Monomer

A small unit that can join to form a polymer.

Monosaccharide

The sugar monomer of carbohydrates; typically contains 5 or 6 carbon atoms.

Fatty Acid

A building block of lipids; long hydrocarbon chain with a carboxyl group; can be saturated or unsaturated.

Amino Acid

The building block of proteins; contains an amino group, a carboxyl group, and a variable side chain.

Nucleotide

Building block of nucleic acids; consists of a phosphate group, a pentose sugar, and a nitrogenous base.

Carbohydrates Building Block

Monosaccharides are the monomer units for carbohydrates.

Lipids Building Block

Fatty acids are the building blocks for lipids.

Proteins Building Block

Amino acids are the building blocks for proteins.

Nucleic Acids Building Block

Nucleotides are the building blocks for nucleic acids.

Polymer

A large molecule made up of repeating monomer units.

Monomer vs Polymer

Monomer is a single subunit; polymer is a chain of monomers.