- Digestion
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Because nutrients can only be absorbed when broken down to their monomers, food digestion is a prerequisite to food absorption. You have already studied the anatomy of digestion.
Enzymes are large protein molecules produced by body cells. They are biologic catalysts that increase the rate of a chemical reaction without themselves becoming part of the product. The digestive enzymes are hydrolytic enzymes, or hydrolases, which break down (catabolize) organic food molecules by adding water to the molecular bonds, thus cleaving the bonds between the subunits or monomers.
The various hydrolytic enzymes are highly specific in their action. Each enzyme hydrolyzes only one or a small group of substrate molecules, and specific environmental conditions are necessary for it to function optimally. Since digestive enzymes actually function outside the body cells in the digestive tract, their hydrolytic activity can also be studied in a test tube. Such an in vitro study provides a convenient laboratory environment for investigating the effect of such variations on enzymatic activity.
| Shown on the left is the progressive digestion of carbohydrates, proteins, and fats. Enzymes produced by the stomach, small intestines, but primarily, the Pancreas catabolize the food macro-molecules into their component monomers. Most Nutrients are absorbed through the endothelium of the small intestines. |
The treatment that fats and oils undergo during digestion in the small intestine is a bit more complicated than that of carbohydrates or proteins. Since fats are not soluble in water, pretreatment with bile to physically emulsify the fats is required. The Gall Bladder stores Bile which is produced by the Liver. Bile is used to solubilize fats so that they can be digested by Lipases (enzymes that digest Lipids).
The
Pancreas produces enzymes, which include protein, carbohydrate, nucleic
acid, and fat-digesting enzymes. These enzymes are required to complete
digestion and are necessary to hydrolyze fats and oils to their components;
glycerol and fatty acids.
Appendicitis Appendicitis is an inflammation of the appendix, a 31/2-inch-long tube of tissue that extends from the large intestine. The appendix contains lymphoid tissue and may produce antibodies; however, no one is absolutely certain what its function is. We can, however, live without it without apparent consequences.
Appendicitis is a medical emergency
that requires prompt surgery to remove the appendix. Left untreated, an
inflamed appendix will eventually burst, or perforate, spilling infection
into the abdominal cavity. This can lead to peritonitis, a serious infection
of the abdominal cavity's lining (the peritoneum) that can be fatal unless
it is treated quickly with strong antibiotics. 
| Appendicitis Symptoms - The classic symptoms of appendicitis include: |
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Sometimes a pus-filled abscess forms outside the inflamed appendix. Fibrous scar tissue then "walls off" the appendix from the rest of the abdomen, preventing infection from spreading. An abscessed appendix is a less urgent situation, but unfortunately, it can't be identified without surgery. For this reason, all cases of appendicitis are treated as emergencies. In the United States, 1 in 15 people gets appendicitis. Although it can strike at any age, appendicitis is rare under age 2 and most common between ages 10 and 30.
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of section 4 
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| Digestive system Disorders |