The small intestine is the site of the complete digestion if carbohydrates, proteins and fats. Then it receives the secretions of the lived a d pancreas. To digest, it is necessary to make it alkaline for the pancreatic enzymes to act, bile juice from liver is secreted for this function. Bile salts break them down into smaller globules increasing the efficiency of enzyme action. The pancreas secretes pancreatic juice, which contains enzymes like trypsin for digesting proteins and lipase for breaking down emulsified fats. The walls of the small intestine contain glands, which secrete intestinal juice. The enzymes present in it finally convert the proteins to amino acids, complex carbohydrates into glucose and fats into fatty acids and glycerol.