As you take a forkful of food into your mouth, the work of the digestive system begins. The teeth tear and crush the food into a fine paste until it is ready to be swallowed. Chewing begins the process of mechanical digestion. Mechanical digestion is the physical breakdown of large pieces of food into smaller pieces. But there is a great deal more to than that. as you chew your food, digestive enzymes begin the breakdown of carbohydrates into smaller molecules. This process is called chemical digestion. During chemical digestion large food molecules are broken down into smaller food molecules. 

Liver:
The liver assists the pancreas. The liver produces bile, a fluid loaded with lipids and salts. Bile acts like a detergent dissolving and dispersing the droplets of fat found in the fatty foods. This action makes it possible for enzymes to reach the smaller fat molecules and break them down. Bile is stored in a small, pouch-like organ called the gall bladder.

Gall Bladder
Stores the bile that is made by the liver.  This bile is then excreted into the small intestine to break up large fat globules into smaller, more digestible pieces.