Recall that bile is produced by the liver and stored in the gall bladder, and understand the role of bile in neutralising stomach acid and emulsifying lipids.
In the stomach is approximately 3, due to the presence of HCL [Hydrochloric Acid], the structure below the stomach, the pancreas, produces digestive enzymes, the liver is responsible for the production of a substanc named bile and is stored in the structure called Gall Bladder. When food is released from the stomach into the small intestine, the ph is approximately 3, this stimulates the release of bile from the gall bladder through the bile duct and to pancreatic duct. So the bile mixes with the digestive enzymes. The point where the pancreatic duct reaches the food the bile has two effects: the first effect is to neutralise the stomach acid and to create a ph whih is approximately 7. This ph is the optimal ph for the digestive enzymes. The second effect of bile is that the fat molecules are broken down into smaller droplets this is a process known as emulsification. A common misunderstanding is that this is an enzyme action. The purpose of the bile breaking fat down into smaller droplets is to increase surface area of the lipid, and that means lipase enzymes can digest the lipid more quickly.