Concept Check Chapter 22 Silverthorn Questions:
1. Explain the roles of the satiety and feeding centers. Where are they located?
2. Studies show that most obese humans have elevated leptin levels in their blood. Based on your
understanding of endocrine disorders [p. 250], propose some reasons why leptin is not decreasing
food intake in these people.
3. Name seven factors that can influence a person’s metabolic rate.
4. Why does the body store most of its extra energy in fat and not in glycogen?
5. Complete and balance the following equation for aerobic metabolism of one glucose molecule:
C6H12O6 + O2 ? + ?
6. What is the RQ for the balanced equation in Concept Check 5?
7. Are GLUT transporters active or passive transporters?
8. What is a dL (as in mg/dL)?
9. Use your understanding of digestive physiology to predict the common side effects of taking bile
acid sequestrants and ezetimibe.
10. What is the difference between glycogenesis and gluconeogenesis?
11. When amino acids are used for energy, which pathways in Figure 22.5 do they follow?
12. Cholesterol is soluble in lipids, so why does plasma cholesterol need the help of a membrane
transporter to enter cells?
13. What are the primary target tissues for insulin?
14. Why are glucose metabolism and glucose transport independent of insulin in renal and intestinal
epithelium and in neurons?
15. What is the advantage to the body of inhibiting insulin release during a sympathetically mediated
fight-or-flight response?
16. For the oral glucose tolerance test, could you use equal amounts (in grams) of table sugar and
expect the same results? Explain.
17. Why must insulin be administered as a shot and not as an oral pill?
18. Patients admitted to the hospital with acute diabetic ketoacidosis and dehydration are given insulin
and fluids that contain K+ and other ions. The acidosis is usually accompanied by hyperkalemia, so
why is K+ included in the rehydration fluids? (Hint: Dehydrated patients may have a high
concentration of K+, but their total body fluid volume is low.)
19. In 2006, the FDA approved sitagliptin (Januvia®), a DPP4 inhibitor. This drug blocks action of the
enzyme dipeptidyl peptidase-4, which breaks down GLP-1 and GIP. Explain how sitagliptin is helpful
in treating diabetes.
20. One of the newest drugs for treating diabetes increases urinary excretion of glucose. It does so by
inhibiting the Na+-glucose cotransporter (SGLT) that allows glucose reabsorption in the proximal
tubule. What are some potential side effects of increasing urinary glucose excretion? [Hint: p. 657]
Concept Check Chapter 22 Answers:
1. Feeding center causes an animal to eat, and satiety center causes an animal to stop eating. Both
centers are in the hypothalamus.
1. Explain the roles of the satiety and feeding centers. Where are they located?
2. Studies show that most obese humans have elevated leptin levels in their blood. Based on your
understanding of endocrine disorders [p. 250], propose some reasons why leptin is not decreasing
food intake in these people.
3. Name seven factors that can influence a person’s metabolic rate.
4. Why does the body store most of its extra energy in fat and not in glycogen?
5. Complete and balance the following equation for aerobic metabolism of one glucose molecule:
C6H12O6 + O2 ? + ?
6. What is the RQ for the balanced equation in Concept Check 5?
7. Are GLUT transporters active or passive transporters?
8. What is a dL (as in mg/dL)?
9. Use your understanding of digestive physiology to predict the common side effects of taking bile
acid sequestrants and ezetimibe.
10. What is the difference between glycogenesis and gluconeogenesis?
11. When amino acids are used for energy, which pathways in Figure 22.5 do they follow?
12. Cholesterol is soluble in lipids, so why does plasma cholesterol need the help of a membrane
transporter to enter cells?
13. What are the primary target tissues for insulin?
14. Why are glucose metabolism and glucose transport independent of insulin in renal and intestinal
epithelium and in neurons?
15. What is the advantage to the body of inhibiting insulin release during a sympathetically mediated
fight-or-flight response?
16. For the oral glucose tolerance test, could you use equal amounts (in grams) of table sugar and
expect the same results? Explain.
17. Why must insulin be administered as a shot and not as an oral pill?
18. Patients admitted to the hospital with acute diabetic ketoacidosis and dehydration are given insulin
and fluids that contain K+ and other ions. The acidosis is usually accompanied by hyperkalemia, so
why is K+ included in the rehydration fluids? (Hint: Dehydrated patients may have a high
concentration of K+, but their total body fluid volume is low.)
19. In 2006, the FDA approved sitagliptin (Januvia®), a DPP4 inhibitor. This drug blocks action of the
enzyme dipeptidyl peptidase-4, which breaks down GLP-1 and GIP. Explain how sitagliptin is helpful
in treating diabetes.
20. One of the newest drugs for treating diabetes increases urinary excretion of glucose. It does so by
inhibiting the Na+-glucose cotransporter (SGLT) that allows glucose reabsorption in the proximal
tubule. What are some potential side effects of increasing urinary glucose excretion? [Hint: p. 657]
Concept Check Chapter 22 Answers:
1. Feeding center causes an animal to eat, and satiety center causes an animal to stop eating. Both
centers are in the hypothalamus.
