1. Most alcohol is absorbed by the small intestine, so the rate of absorption and the tendency toward intoxication depend on how fast the stomach is emptied. The fat in cream inhibits gastric emptying and thus reduces the rate of alcohol absorption.

2. Removal of the pancreas would have the most severe effects on absorption because most chemical digestion occurs in the small intestine and requires the action of pancreatic enzymes. The digestive functions of the stomach and gallbladder, while helpful, are not indispensible.

3. Both of these enzymes function in the small intestine to remove one amino acid at a time from short peptides, but they differ in the following ways: (a) carboxypeptidase removes the amino acid from the –COOH end and aminopeptidase removes the amino acid from the –NH₂ end; and (b) aminopeptidase occurs only on the brush border and works only by contact digestion, whereas carboxypeptidase occurs here as well as in the pancreatic juice.

4. Both micelles and chylomicrons are small coated droplets of lipid. Micelles are coated with bile salts and lecithin, they are smaller than chylomicrons, and they are produced in the lumen of the small intestine as chyme mixes with bile. Chylomicrons are coated with protein, they are larger, they are produced in the absorptive epithelial cells of the small intestine, and they occur in the lymph and blood.

5. Lipids are hydrophobic and cannot freely mix with the body fluids. To transport them in the blood and lymph, the digestive tract coats them with proteins to form chylomicrons. These droplets are too large to pass through the walls of a blood capillary, but they can pass through the larger intercellular clefts of a lymphatic capillary (the lacteal) and enter the lymph.

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