The first step in lipolysis is the hydrolysis of triacylglycerol (TAG) into diacylglycerol (DAG) and a free fatty acid. This process is catalyzed by the enzyme adipose triglyceride lipase (ATGL).
ATGL is considered the rate-limiting enzyme for the initial step of lipolysis, meaning that its activity determines the overall rate of lipolysis.
In summary, the first step in lipolysis is the breakdown of TAG into DAG and a free fatty acid, catalyzed by the enzyme ATGL.
