functional groups
Molecule's reactive parts
Functional groups are specific clusters of atoms within molecules that determine how the molecule behaves chemically.
In organic chemistry, compounds are classified by their functional groups—hydroxyl groups define alcohols, carboxyl groups define acids, amino groups define amines.
Molecules with the same functional group tend to react similarly, making these groupings central to understanding chemical behavior: The carbonyl functional group is present in both aldehydes and ketones.
-OH functional group
- carbonylC=O functional group
- carboxyl-COOH functional group
- aldehydeCarbonyl bonded to hydrogen
- ketoneCarbonyl between two carbons
amine · amide · ester · ether · alcohol · phenol · thiol · halide
Acid in proteins
- carboxyl-COOH functional group
- phosphatePO₄ ion compound
- peptideShort amino acid chain
- disulfideTwo-sulfur chemical linkage
indole · phenolic · N-terminal · cofactor · prosthetic · acetyl · methyl
Electron-pair acceptor species
- nucleophileElectron-pair donating species
- polarityState of opposing forces
- resonanceAmplified oscillation at natural frequency
- inductiveDeriving general from particular
directing · activating · deactivating · ortho · meta · para · substitution · addition
Forming esters chemically
- alkylationAdding hydrocarbon groups chemically
- nitrationNitro group insertion process
- sulfonationAttaching sulfonic groups chemically
- hydrogenationBonding hydrogen to compounds
decarboxylation · saponification · condensation · phosphorylation · oxidation · reduction · hydrolysis · protection
Heat-bearing electromagnetic waves
- spectroscopyStudy of light-matter interaction
- chromatographyTechnique separating mixtures by differential migration
- fingerprintFriction ridge impression
- absorptionProcess of taking in
stretching · bending · fragmentation · staining · titration · indicator · characteristic · Lucas
hydroxyl
-OH functional group
ketone · amine · amide · ester · ether · alcohol · phenol · thiol · halide · nitrile
amino
Acid in proteins
disulfide · indole · phenolic · N-terminal · cofactor · prosthetic · acetyl · methyl
electrophile
Electron-pair acceptor species
- nucleophileElectron-pair donating species
- polarityState of opposing forces
- resonanceAmplified oscillation at natural frequency
inductive · directing · activating · deactivating · ortho · meta · para · substitution · addition · elimination
esterification
Forming esters chemically
- alkylationAdding hydrocarbon groups chemically
- nitrationNitro group insertion process
- sulfonationAttaching sulfonic groups chemically
hydrogenation · decarboxylation · saponification · condensation · phosphorylation · oxidation · reduction · hydrolysis · protection · coupling
infrared
Heat-bearing electromagnetic waves
- spectroscopyStudy of light-matter interaction
- chromatographyTechnique separating mixtures by differential migration
- fingerprintFriction ridge impression
absorption · stretching · bending · fragmentation · staining · titration · indicator · characteristic · Lucas · chromophore
functional groupsmolecular formula
Notation showing atomic composition
group, function, functional, functioning, malfunction, functions, functioned, functionary, functionality