Functional Groups

Hydroxyl

Structural Formula: an oxygen atom bonded to a hydrogen atom (−OH)

Properties: Hydrophilic and polar —> increasing solubility in water Examples: alcohols (ex. ethanol), carbohydrates (ex. sugars)

Carbonyl (Aledhyde)

Structural Formula: a carbon atom double-bonded to an oxygen atom (C=O) and bonded to a hydrogen (found at the end of a carbon chain)

Properties: polar —> boiling points and solubility.

Examples: Formaldehyde (methanal), vanillin, sugars

Carbonyl (Ketone)

Structural Formula: a carbon atom double-bonded to an oxygen atom (C=O), with 2 available bonds to connect in a carbon chain (found in the middle of a carbon chain)

Properties: polar

Examples: acetone, methylethyl ketone, cyclohexanone

Carboxyl

Structural Formula: a carbon atom double-bonded to an oxygen atom and also bonded to a hydroxyl group (−COOH).

Properties: polar, (acts as an acid by donating protons, contributing to acidity in solutions.

Examples: carboxylic acids (ex. acetic acid (vinegar), citric acid (vitamins), fatty acids)

Amino

Structural Formula: a nitrogen atom bonded to two hydrogen atoms (−NH2).

Properties: polar, basic (can accept protons), forming ammonium ions.

Examples: amino acids (ex. glycine), proteins, ammonia

Sulfhydryl

Structural Formula: sulfur atom bonded to a hydrogen atom (−SH). Properties: polar, contributes to the structure of proteins through disulfide bonds, influencing protein folding.

Examples: proteins, rubber

Phosphate

Structural Formula: a phosphorus atom bonded to four oxygen atoms (−PO4).

Properties: Highly polar and negatively charged, affecting molecular interactions.

Examples: nucleic acids (DNA and RNA), ATP (adenosine triphosphate), phospholipids

Methyl

Structural Formula: a carbon atom bonded to three hydrogen atoms (−CH3).

Properties: non polar (hydrophobic), often preventing hydrogen bonding.

Examples: methane, many fatty acids.