Question

the transfer of a phosphate group to a molecule or compound is called...
carboxylation.
ionization.
phosphorylation.
hydrogen bonding.
hydrogenation.

Explanation:

Carboxylation is the addition of a carboxyl group. Ionization is the process of forming ions. Hydrogen bonding is a type of intermolecular force. Hydrogenation is the addition of hydrogen. Phosphorylation specifically refers to the transfer of a phosphate group.

Answer:

phosphorylation.