1. Functional Groups

2. Hydroxyl group: --OH Polar, since O—H bond is polar covalent
Makes molecule water-soluble, with –OH forming hydrogen bonds
Organic compounds with hydroxyl groups are called ALCOHOLS.
Example: ethanol (C-C-OH) in alcoholic drinks

3. Carbonyl group: --CO
Functional group with a carbon double-bonded to an oxygen atom
Polar group, making molecules water-soluble
Functional group found in sugars. If carbonyl group is at the end of the carbon chain, the molecule is a Aldehyde, otherwise it is an Ketone.
Ex. Propanol (aldehyde) and acetone (ketone)

4. Carboxyl group: --COOH
Group consists of a carbon atom double-bonded to an oxygen atom, and single-bonded to a hydroxyl group
Polar group, molecules are water-soluble
H+ can disassociate, giving the molecule acidic properties.
Compounds with group are called CARBOXYLIC ACIDS.
Ex. Acetic Acid (in vinegar)

5. Polar group that is water-soluble.
Amino group: --NH2
Polar group that is water-soluble.
Acts as a weak base, accepting a proton (H+)
Organic compounds with group are called AMINES.
NOTE: Amino acids (monomers of proteins) have both an amino group and a carboxyl group

6. Sulfhydryl group:--SH
Help stabilize the structure of proteins
Organic compounds with this functional group are THIOLS.
Ex. Cysteine
Sulfhydryl groups formed in hair during perms to give curly form

7. Dissociated form of H3PO4 Has acidic properties since it loses H+
Phosphate group: --PO4
Dissociated form of H3PO4
Has acidic properties since it loses H+
Polar group, soluble in water
Compounds are ORGANIC PHOSPHATES, important in cellular energy storage and transfer (ATP).

8. Nonpolar, hydrophobic (all other functional groups are hydrophilic)
Methyl group: --CH3
Nonpolar, hydrophobic (all other functional groups are hydrophilic)
Important group in nonpolar amino acids, contributing to the tertiary structure of proteins
Compounds containing a methyl group are called methylated compounds