Nutrition and Digestion

887 Words Jun 3rd, 2013 4 Pages
Module 2 Written Assignment

1. What are enzymes? What specifically is the role of an enzyme in digestion?

Enzymes are working proteins that facilitate chemical reactions without being changed in the process. Organs of the digestive system excrete digestive juices, which contain enzymes that break the bonds of nutrients that can be absorbed.

2. Trace the path of a cheeseburger and fries through the digestive tract. Indicate each place where mechanical digestion, chemical digestion, and absorption occurs FOR EACH NUTRIENT (carbohydrates, lipids, proteins). Be sure to fully explain the role of EACH organ involved (including the pancreas, liver, and gallbladder).

In the mouth – food is crushed and chewed by teeth (mechanical
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The small intestine also contributes enzymes to complete the digestion process before nutrients are small enough for the cells to absorb (chemical).
In the large intestine – The digestion and absorption of proteins, fats and carbohydrates are essentially complete by the time the intestinal contents enter the colon. Only water, fiber and some minerals remain. Only certain fibers can be broken down by bacteria (chemical digestion).The colon's task is mostly to reabsorb water and minerals, leaving a paste of fiber and feces for excretion (mechanical) via rectum and anus.

3. How is the lining of the small intestine protected from acidic chyme entering from the stomach?

The pyloric valve of the lower stomach regulates the amount of chyme that exits into the small intestine, allowing only a little at a time to exit. Also, once chyme enters the small intestine, hormonal messengers signal the pancreas to release alkaline pancreatic juice, bicarbonate, to neutralize the stomach acid that has reached the small intestine.

4. Where are carbohydrates stored in the body? In what form are carbohydrates stored?

Carbohydrates are stored in the liver in the form of glycogen.

5. What happens to the volume (amount) and dilution (amount of water) of urine when alcohol is consumed? Explain in detail why this occurs, focusing…

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