Final answer:
Cholecystokinin (CCK) is the hormone released in response to proteins and fats in chyme that stimulates pancreatic enzyme release and bile salt secretion from the gallbladder for digestion.
Step-by-step explanation:
The hormone cholecystokinin (CCK), released in response to protein and fat in chyme, stimulates the release of digestive enzymes from the pancreas, for which the stimulating molecules are substrates. CCK plays a crucial role in digestion by not only promoting the secretion of enzyme-rich pancreatic juice but also aiding in the contraction of the gallbladder to release bile salts, which are essential for fat digestion.
CCK enhances the activity of another hormone called secretin, which causes the pancreatic duct cells to release bicarbonate-rich pancreatic juice. This helps to neutralize the highly acidic chyme that enters the duodenum from the stomach. The coordinated release of these hormones is critical for proper digestive function.