Carbon Molecules, Water Properties, and Functional Groups

Vocabulary practice flashcards covering the pH scale, water properties, atomic carbon structure, isomers, and functional groups.

pH

A measure of hydrogen ion ($\text{H}^+$) concentration in a solution, used to infer hydroxide ion ($\text{OH}^-$) concentration.

Logarithmic pH Scale

A scale ranging from $0$ to $14$ where each unit difference represents a $10\text{-fold}$ difference in hydrogen ion concentration.

Hydrogen Bond

An attraction between a hydrogen atom with a partial positive charge and an electronegative atom with a partial negative charge.

Intermolecular Hydrogen Bond

A hydrogen bond occurring between two separate molecules, such as between individual water molecules.

Intramolecular Hydrogen Bond

A hydrogen bond occurring within a single molecule, such as within the secondary structure of a protein.

High Specific Heat

The amount of heat needed to raise or lower $1\,\text{g}$ of a substance by $1\,^\circ\text{C}$, allowing water to resist temperature changes.

High Heat of Vaporization

The amount of energy required to convert $1\,\text{g}$ of a substance from a liquid to a gas, during which hydrogen bonds break and heat is removed.

Atomic Number

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

Atomic Mass

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

Catenation

The ability of carbon atoms to form covalent bonds with other carbon atoms to build long chains and ring structures.

Isomers

Compounds that share the same chemical formula but have different structural arrangements, resulting in distinct physical and chemical properties.

Structural Isomer

Isomers that have the same chemical formula but differ in the covalent bonding arrangement among their atoms.

Stereoisomer

Isomers with the same chemical formula and atom bonding order, but differing 3D spatial arrangements of their atoms.

Thalidomide

An optical stereoisomer where the (R)-enantiomer is effective against nausea, while the (S)-enantiomer intercalates into DNA and acts as a mutagenic teratogen.

Teratogen

An agent that causes developmental abnormalities or malformations in a fetus (from Greek teratos, meaning monster).

L-Dopa

The biologically active stereoisomer of Dopa that is effective against Parkinson's disease, unlike its inactive counterpart D-Dopa.

Functional Group

A specific group of atoms attached to a carbon skeleton that dictates a molecule's chemical properties, polarity, acidity, solubility, and reactivity.

Hydroxyl Group

A polar functional group consisting of an oxygen atom bonded to a hydrogen atom ($\text{-OH}$), characteristic of alcohols and sugars.

Carbonyl Group

A functional group with a carbon atom double-bonded to an oxygen atom ($\text{C=O}$), found in aldehydes and ketones as metabolic intermediates.

Carboxyl Group

An acidic functional group ($\text{-COOH}$) composed of a carbonyl group and a hydroxyl group attached to the same carbon, found in amino acids and fatty acids.

Amino Group

A basic functional group composed of a nitrogen atom bonded to two hydrogen atoms ($\text{-NH}_2$), present in amino acids and proteins.

Zwitterion

An overall neutral internal salt form of an amino acid at physiological pH ($7.4$) where the amino group is protonated ($\text{-NH}_3^+$) and the carboxyl group is deprotonated ($\text{-COO}^-$).

Sulfhydryl Group

A functional group consisting of sulfur bonded to hydrogen ($\text{-SH}$), found in cysteine that forms disulfide bridges to stabilize tertiary protein structures.

Phosphate Group

A functional group composed of a phosphorus atom bonded to four oxygen atoms ($\text{-PO}_4$ or $\text{-H}_2\text{PO}_4$), found in nucleotides (DNA and RNA) and ATP.

Methyl Group

A nonpolar functional group consisting of 1 carbon bonded to 3 hydrogen atoms ($\text{-CH}_3$), attached to molecules like DNA to silence gene expression.

DNA Methylation

An epigenetic modification where methyl groups attach to DNA or histone tails, rendering DNA inaccessible and silencing gene expression.