Final answer:
Phosphatases are enzymes that remove phosphate groups from molecules in signaling pathways, a process called dephosphorylation, and are integral for the regulation of these pathways.
Step-by-step explanation:
Phosphatases play a critical role in signal transduction pathways by removing phosphate groups from molecules. This process is known as dephosphorylation. When a kinase enzyme adds a phosphate group to a molecule like a protein, the shape and function of that protein can be altered, often activating or inactivating it. Phosphatases reverse this modification by removing the phosphate group, which can also activate or inactivate the protein, thereby reversing the effect of phosphorylation.
This is essential for regulating the signaling pathways, ensuring that signals can be turned off when they are no longer needed. For example, a phosphatase might remove a phosphate from a serine, threonine, or tyrosine residue on a protein, changing its shape and activity.