Functional Groups - AP Bio

hydroxyl group (-OH)

• found in macromolecules

• makes alcohols (ethanol, glycerol)

• Is always polar

• can form hydrogen bonds

carbonyl group (C=O)

• aldehydes appear at the end

• ketones appear within

• found in sugars

• polar

• hydrophillic

carboxyl group (-COOH)

• organic acids (amino acids, fatty acids)

• acts as an acid; can donate an H⁺ to solution

• found in cells in the ionized form with a negative charge

amino group (-NH₂)

• contains nitrogen

• acts as a base; can pick up an H⁺ from the surrounding solution

• found in cells in the ionized form with a positive charge

• found in nucleic acids and proteins

sulfhydryl group (-SH)

• found in the amino acid cysteine (contains sulfur - only found in proteins)

• 2 groups = covalent bond; “cross-linking” - stabilize protein structure

• found in rubber

phosphate group (-PO₄^-2)

• contains phosphorus

• found in nucleic acids (and ATP)

• negatively charged

• energy transfer

methyl group (-CH₃)

• non-polar

• found in macromolecules

• adding the group to DNA affects the expression of genes