Nutrition and Absorption
Fats

Fats (lipids)

Lipids consist of the elements carbon, hydrogen, oxygen and sometimes phosphorus and nitrogen. Lipids belong to a large group that includes fats and oils, which are insoluble in water. A common type of fatty acid is the triglycerides, which are composed of a glycerol backbone and three fatty acids.

Fats provide an important source of energy for all organisms and they are also a good insulator of heat, preventing heat loss in extreme temperatures. Fats act as a protective cushion around vital organs such as the liver, kidney and spleen to help prevent injury.

Digestion of fats

The digestion of fats mainly takes place in the duodenum of the small intestine. Bile produced by the liver and stored in the gall bladder is used to emulsify fats by lowering their surface tension, which causes them to break up into numerous tiny droplets. This increases the surface area for the action of the pancreatic lipase enzyme. Pancreatic lipase breaks down fats into fatty acids and glycerol, which are then transported to the lymphatic system and then into the bloodstream.