What does covalent modification of proteins primarily involve?

Covalent modification of proteins primarily involves permanent chemical changes that can significantly impact the protein's function and activity. This process includes the addition or removal of specific chemical groups, such as phosphate, methyl, or acetyl groups, which can alter the protein’s conformation and, consequently, its interaction with other molecules. By modifying the protein's structure at the molecular level, these modifications can either activate or deactivate the protein, thereby regulating metabolic pathways and cellular functions.

This dynamic regulation plays a crucial role in signal transduction, gene expression, and enzymatic activity, allowing cells to respond to changing conditions and maintain homeostasis. Therefore, the emphasis on the alteration of function and activity accurately reflects the central concept of covalent modifications in biochemical regulation.