1. Slide 1 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. Chapter 16 Nutrition and Metabolism

2. Slide 2 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. DEFINITIONS  Nutrition—food, vitamins, and minerals that are ingested and assimilated into the body  Metabolism—process of using food molecules as energy sources and as building blocks for our own molecules  Catabolism—breaks food molecules down, releasing their stored energy; oxygen used in catabolism  Anabolism—builds food molecules into complex substances

3. Slide 3 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. ROLE OF THE LIVER  Secretes bile, which breaks down large fat globules  Helps maintain normal blood glucose level  Helps metabolize carbohydrates, fats, and proteins; synthesizes several kinds of protein compounds  Removes toxins from the blood

4. Slide 4 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. NUTRIENT METABOLISM  Carbohydrates—preferred energy food of the body  Three series of chemical reactions in glucose metabolism Glycolysis Glycolysis  Changes glucose to pyruvic acid  Anaerobic (uses no oxygen)  Yields small amount of energy, generating 2 ATPs  Occurs in cytoplasm Citric acid (Krebs) cycle Citric acid (Krebs) cycle  Changes pyruvic acid to carbon dioxide  Aerobic (requires oxygen)  Yields large amount of energy (mostly as high energy electrons)  Occurs in mitochondria Electron transfer system Electron transfer system  Transfers energy from high energy electrons (from citric acid cycle) to ATP molecules  Located in mitochondria

5. Slide 5 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. NUTRIENT METABOLISM (cont.)  Carbohydrates (cont.)  The mitochondrial part of the pathway (citric acid cycle and electron transport system) is aerobic (requires oxygen) and generates up to 36 ATP molecules per original glucose molecule  Carbohydrates are primarily catabolized for energy (Figure 16-1)  Adenosine triphosphate (ATP)—molecule in which energy obtained from breakdown of foods is stored; serves as a direct source of energy for cellular work (Figure 16-2)  Storage of glucose Glucose that is not needed immediately for making ATP is stored as glycogen (a long chain of glucose subunits) in the liver and muscle cells Glucose that is not needed immediately for making ATP is stored as glycogen (a long chain of glucose subunits) in the liver and muscle cells Glycogenesis – anabolic process of joining glucose molecules together in a chain to form glycogen (to store glucose for later use) Glycogenesis – anabolic process of joining glucose molecules together in a chain to form glycogen (to store glucose for later use) Glycogenolysis – catabolic process of breaking apart glycogen chains, releasing individual glucose molecules for use in making ATP Glycogenolysis – catabolic process of breaking apart glycogen chains, releasing individual glucose molecules for use in making ATP

6. Slide 6 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.

7. Slide 7 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.

8. Slide 8 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. NUTRIENT METABOLISM (cont.)  Carbohydrates (cont.)  Blood glucose (imprecisely, blood sugar)—normally stays between about 80 and 110 mg per 100 mL of blood during fasting; insulin accelerates the movement of glucose out of the blood into cells, therefore decreases blood glucose and increases glucose catabolism  Fats—catabolized to yield energy and anabolized to form adipose tissue (Figure 16-3)  Proteins—primarily anabolized and secondarily catabolized

9. Slide 9 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.

10. Slide 10 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. VITAMINS AND MINERALS  Vitamins—organic molecules that are needed in small amounts for normal metabolism (Table 16-2)  Minerals—inorganic molecules found naturally in the earth, required by the body for normal function (Table 16-3)

11. Slide 11 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.

12. Slide 12 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.

13. Slide 13 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. METABOLIC RATES  Basal metabolic rate (BMR)—rate of metabolism when a person is lying down but awake and not digesting food and when the environment is comfortably warm  Total metabolic rate (TMR)—the total amount of energy, expressed in calories, used by the body per day (Figure 16-4)

14. Slide 14 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.

15. Slide 15 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. BODY TEMPERATURE  Hypothalamus—regulates the homeostasis of body temperature (thermoregulation) through a variety of processes  Skin—can cool the body by losing heat from the blood through four processes: radiation, conduction, convection, evaporation (Figure 16-5)

16. Slide 16 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.