Absorption of Food and nutrition

The process by which the end products of digestion pass through the lining of the digestive tract is called absorption. Absorption takes place through the inner lining of the small intestine called villi. the simple sugar and amino acids enter into the blood directly while the fatty acids enter the blood system indirectly through the lymphatic system.

Site	Digestive juice	Optimum pH	Enzyme	Functions (reactions)
Mouth	Saliva	Alkaline	Ptyalin	Starch          maltose
Stomach	Gastric juice	Acidic (due to the presence of hydrochloric acid)	Pepsin    Renin	Converts protein to peptide and peptone. Acts on milk proteins only and curdles it by converting the caseinogen (soluble) to casein (insoluble)
Duodenum	Bile secreted by the gall bladder Pancreatic juice produced by the pancreas	Alkaline   Alkaline	Contains no enzyme but bile salts amylase Trypsin lipase	The bile salts emulsify the fats.   Starch   >>>             maltose    Protein  >>> peptides/peptones                   Fats    >>> fatty acids and glycerol
Small intestine or ileum	Intestinal juice	Alkaline	Maltase Lactase Sucrose Peptidase Lipase

Assignment: draw and label fully a diagram showing the alimentary canal.