BIOL101 - Molecules of Life: Atoms, Bonds, and Macromolecules

Vocabulary practice flashcards generated from BIOL101 lecture notes covering chemical foundations, water properties, and macromolecular structures.

Proton

A positively charged subatomic particle found in the atomic nucleus that has mass.

Neutron

A subatomic particle located in the atomic nucleus that carries no charge and has mass.

Electron

A negatively charged subatomic particle that orbits the nucleus and has very little mass.

Atomic number

The number of protons contained within the nucleus of an atom.

Atomic mass

The sum of the number of protons and the number of neutrons in an atom.

Isotopes

Atoms of the same element that differ in their number of neutrons while maintaining the same number of protons and electrons.

Ion

An atom that has gained or lost electrons, acquiring a net electrical charge.

Cation

A positively charged ion formed when an atom loses one or more electrons.

Anion

A negatively charged ion formed when an atom gains one or more electrons.

Valence electrons

The electrons located in the outermost electron shell of an atom that determine its chemical reactivity and bonding capacity.

Covalent bond

A chemical bond formed when two atoms share valence electrons to fill their outer shells.

Polar covalent bond

A type of covalent bond that results from the unequal sharing of electrons between atoms with different electronegativities.

Nonpolar covalent bond

A type of covalent bond formed when electrons are shared equally between atoms.

Electronegativity

The intrinsic ability of an atom to attract shared electrons toward itself within a chemical bond.

Ionic bond

A chemical bond formed by the electrostatic attraction between oppositely charged ions.

pH

A measure of the concentration of hydrogen ions ($H^+$) and hydroxide ions ($OH^-$) in a solution, calculated as $pH = -\log[H^+]$.

Proteins

Biological macromolecules composed of amino acid monomers linked together by peptide bonds.

Polypeptide

A linear chain of amino acids connected by peptide bonds.

Pyrimidines

Nitrogenous base components of nucleotides characterized by a single ring structure, including Cytosine, Thymine, and Uracil.

Purines

Nitrogenous base components of nucleotides characterized by a double ring structure, including Guanine and Adenine.

Phosphodiester bond

The covalent linkage that connects adjacent nucleotides along a nucleic acid strand.

Glycosidic bond

The covalent bond that links monosaccharide units together to form complex carbohydrates or polysaccharides.

Saturated fatty acid

A fatty acid chain that contains no carbon-carbon double bonds, maximizing the number of attached hydrogen atoms.

Unsaturated fatty acid

A fatty acid chain that contains one or more carbon-carbon double bonds.

Triacylglycerol

A lipid molecule formed by attaching three fatty acid chains to a single glycerol backbone.

Van der Waals forces

Weak electrostatic attractions between nonpolar molecules or hydrocarbon chains caused by temporary partial charges from constantly moving electrons.

Steroids

A class of lipids composed of carbon atoms arranged in four fused ring structures, including molecules like cholesterol.