Phosphorylation

Kinase: An enzyme that catalyzes the transfer of phosphate groups from high-energy donor molecules (like ATP) to specific target molecules in a process called phosphorylation.

Dephosphorylation: The removal of a phosphate group from an organic compound by hydrolysis. It's essentially the reverse process of phosphorylation and can also regulate protein function.

Signal Transduction: As mentioned earlier, this is how cells communicate and respond to their environment. Phosphorylation plays a key role in transmitting these signals within cells.