Transferases are a class of enzymes that facilitate the transfer of specific functional groups from one molecule to another. These functional groups can include methyl, phosphate, or amino groups, among others. By catalyzing these reactions, transferases play a crucial role in various biochemical processes, including metabolism and signal transduction. One common example of a transferase is kinase, which transfers phosphate groups to substrates, often using ATP as a phosphate donor. This action is vital for regulating cellular activities, such as energy production and cell signaling. Overall, transferases are essential for maintaining the proper functioning of biological systems.