Final answer:
Phosphorylation is a critical regulatory mechanism in cells that involves adding a phosphate group to proteins, hence altering their function and impacting gene expression.
Step-by-step explanation:
Proteins can be regulated through a process called phosphorylation, which involves the addition of a phosphate group to a protein molecule. This modification can significantly affect the protein's function, such as its enzyme activity, interaction with other molecules, or cellular location. Kinases are the enzymes responsible for adding the phosphate group in a process called phosphorylation, while phosphatases remove these groups through dephosphorylation. In biological systems, phosphorylation is a crucial regulatory mechanism that can alter gene expression by influencing protein interactions, protein stability, and enzyme activity. For example, cyclins regulate the cell cycle by forming complexes with Cyclin-dependent kinases (Cdks), which must be phosphorylated at specific sites to be fully active, thereby advancing the cell to the next phase. The dynamic balance of phosphorylation and dephosphorylation facilitates precise control over various cellular processes, including signaling pathways that impact gene expression.