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BIO 140 Human Biology I - Questions and Solutions

Chemical Digestion and Absorption - Solutions

Review Questions

1. Where does the chemical digestion of starch begin?

  1. mouth
  2. esophagus
  3. stomach
  4. small intestine
2. Which of these is involved in the chemical digestion of protein?
  1. pancreatic amylase
  2. trypsin
  3. sucrase
  4. pancreatic nuclease
3. Where are most fat-digesting enzymes produced?
  1. small intestine
  2. gallbladder
  3. liver
  4. pancreas
4. Which of these nutrients is absorbed mainly in the duodenum?
  1. glucose
  2. iron
  3. sodium
  4. water

 

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Critical Thinking Questions

1. Explain the role of bile salts and lecithin in the emulsification of lipids (fats).

Solution: Bile salts and lecithin can emulsify large lipid globules because they are amphipathic; they have a nonpolar (hydrophobic) region that attaches to the large fat molecules as well as a polar (hydrophilic) region that interacts with the watery chime in the intestine.

2. How is vitamin B12 absorbed?

Solution: Intrinsic factor secreted in the stomach binds to the large B12 compound, creating a combination that can bind to mucosal receptors in the ileum.

 

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OpenStax, Chemical Digestion and Absorption: A Closer Look. OpenStax CNX. Feb 6, 2017 http://cnx.org/contents/9a926b86-67d0-4dbe-b5fe-d94581825886@6. © Feb 6, 2017 OpenStax. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution License 4.0 license.