Introduction to Chemistry of Life & Biomolecules (BIO 108)

A set of vocabulary flashcards covering key terms from the lecture, including atomic structure, chemical bonding, water properties, pH, organic compounds, and biomolecules (carbohydrates, nucleic acids, proteins, lipids) and polymer formation/destruction.

Element

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

Atom

The smallest unit of matter that retains the properties of an element.

Compound

A substance consisting of two or more elements in a fixed ratio with emergent properties.

Periodic Table

Organization of elements by increasing atomic number and similar properties.

Atomic number

Number of protons in an atom's nucleus; identifies the element.

Atomic symbol

Abbreviated one- or two-letter symbol for an element (e.g., H, C, Na).

Atomic mass

Average mass of an element's atoms; used to describe mass in atomic units.

Proton

Positively charged subatomic particle in the nucleus.

Electron

Negatively charged subatomic particle in orbit around the nucleus; determines charge and energy levels.

Neutron

Electrically neutral subatomic particle in the nucleus; adds to atomic mass.

Trace elements

Elements required in very small amounts for normal physiological function.

Major elements

Elements required in relatively large amounts (e.g., C, H, O, N…).

Metals

Elements that tend to lose electrons and form cations; often conductive.

Nonmetals

Elements that tend to gain electrons; usually poor conductors.

Covalent bond

Bond formed by sharing a pair of valence electrons between atoms.

Polar covalent bond

Covalent bond with unequal sharing of electrons, creating partial charges.

Nonpolar covalent bond

Covalent bond with equal sharing of electrons.

Ionic bond

Bond formed by transfer of electrons, creating ions held together by attraction.

Water

A life-essential solvent with cohesion, adhesion, surface tension, temperature moderation, and solvent properties.

Cohesion

Attraction between water molecules.

Adhesion

Attraction of water to other substances.

Surface tension

cohesive forces at the air-water interface that make the surface behave as if covered with a film.

Temperature moderation (water's heat capacity)

Water moderates Earth's temperature due to its high heat capacity.

Ice floats

Solid water is less dense than liquid water, so ice floats.

Solvent

A substance (like water) that dissolves solutes to form solutions.

pH

Measure of the hydrogen ion concentration in a solution.

Acid

A substance that dissociates in water to release H+ ions.

Base

A substance that accepts H+ ions in solution.

Organic compound

Compound that contains carbon and is typical of living systems.

Carbon

Element central to organic chemistry; forms large, diverse molecules due to tetravalence.

Monomer

Small unit that can join to form polymers.

Polymer

Long chain of monomers linked by covalent bonds.

Macromolecule

Large biomolecule such as carbohydrates, proteins, nucleic acids, or lipids.

Monosaccharide

Simple sugar; empirical formula often CH2O units; e.g., glucose.

Disaccharide

Two monosaccharides joined by a glycosidic linkage.

Polysaccharide

Polymers composed of many monosaccharide units; storage or structural roles (e.g., starch, glycogen, cellulose, chitin).

Glycosidic linkage

Covalent bond joining monosaccharides in carbohydrates.

Nucleic acid

DNA or RNA; stores and transmits genetic information.

Nucleotide

Monomer of nucleic acids; consists of a sugar, phosphate, and nitrogenous base.

Phosphodiester

Backbone linkage that connects nucleotides in nucleic acids.

Backbone (nucleic acids)

Sugar-phosphate chain that forms the backbone of DNA/RNA.

DNA

Deoxyribonucleic acid; stores genetic information in cells.

RNA

Ribonucleic acid; functions in protein synthesis and gene expression.

Protein

Macromolecule with diverse roles including enzymes, defense, transport, and signaling.

Amino acid

Monomer of proteins containing amino and carboxyl groups with a side chain.

Peptide bond

Bond linking amino acids in a protein.

Enzyme

Biological catalyst that speeds up reactions by lowering activation energy.

Substrate

Reactant that binds to an enzyme's active site.

Active site

Region of an enzyme where the substrate binds and the reaction occurs.

Lipid

Non-polymeric biomolecule class including fats, phospholipids, and steroids; hydrophobic or amphipathic.

Triglyceride

Fat composed of three fatty acids bonded to glycerol.

Phospholipid

Lipid with two fatty acids and a phosphate group; forms cellular membranes.

Steroid

Lipid with four fused carbon rings; includes cholesterol and hormone precursors.

Cholesterol

Steroid that modulates membrane fluidity and serves as hormone precursor.

ATP

Adenosine triphosphate; primary energy-currency of the cell; energy stored in phosphate bonds.

Dehydration synthesis

Chemical reaction that forms a polymer by removing a water molecule.

Hydrolysis

Polymer breakdown by adding water; reverse of dehydration synthesis.

Protein structure levels

Primary, secondary, tertiary, and quaternary structures describe polypeptide organization and folding.

Activation energy

Minimum energy required for a chemical reaction to proceed.