phosphorylation

This term describes a precise biochemical modification used as a molecular switch. It carries a clinical and scientific connotation, typically appearing in academic papers, medical textbooks, and laboratory reports to describe the activation or inactivation of enzymes.

As a mass noun representing a chemical process, it is treated as uncountable. It does not refer to a discrete object but to a systemic reaction, meaning it cannot be pluralized to describe multiple instances of the process without using a partitive phrase like "instances of phosphorylation."