1. BIOLOGY CONCEPTS & CONNECTIONS Fourth Edition Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Neil A. Campbell Jane B. Reece Lawrence G. Mitchell Martha R. Taylor From PowerPoint ® Lectures for Biology: Concepts & Connections CHAPTER 21 Nutrition and Digestion Modules 21.12 – 21.20

2. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Herbivores and omnivores generally have longer alimentary canals than carnivores –Plant matter is more difficult to digest than meat –Nutrients in vegetation are less concentrated than in meat 21.12 Adaptations of vertebrate digestive systems reflect diet DIETS AND DIGESTIVE ADAPTATIONS

3. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 21.12A CARNIVOREHERBIVORE Small intestine Stomach Cecum Colon (large intestine) Small intestine

4. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Some mammals house cellulose-digesting microbes in the colon or cecum –The cecum is a pouch where the large and small intestines connect –Examples: horses and elephants Other mammals re-ingest their feces to recover nutrients –Examples: rabbits and some rodents

5. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Ruminants such as cows process cellulose in a four-chambered stomach Figure 21.12B Intestine 3 Omasum 1 Rumen 4 Abomasum Rumen Esophagus 2 Reticulum

6. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings An animal’s diet provides –fuel for its activities –raw materials for making the body’s own molecules –essential nutrients that the body cannot make 21.13 Overview: A healthful diet satisfies three needs NUTRITION

7. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Once nutrients are inside cells, they can be oxidized by cellular metabolism to generate energy –This energy is in the form of ATP 21.14 Chemical energy powers the body

8. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The energy a resting animal requires each day to stay alive is its basal metabolic rate (BMR) Figure 21.14

9. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings More energy is required for an active life –Excess energy is stored as glycogen or fat Table 21.14

10. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The human body tends to store excess fat molecules instead of using them for fuel A balanced diet includes adequate amounts of all nutrients 21.15 Connection: Body fat and fad diets

11. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Fad diets are often ineffective and can be harmful Table 21.15

12. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The eight essential amino acids that adults require must be obtained from food –They are easily obtained from animal protein –They can also be obtained from the proper combination of plant foods 21.16 Connection: Vegetarians must be sure to obtain all eight essential amino acids Figure 21.16 ESSENTIAL AMINO ACIDS Methionine Valine (Histidine) Threonine Phenylalanine Leucine Isoleucine Tryptophan Lysine Beans and other legumes Corn

13. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Most of these vitamins function as coenzymes 21.17 Connection: A healthful diet includes 13 vitamins

14. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Table 21.17 (Water-soluble vitamins)

15. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Table 21.17 (Fat-soluble vitamins)

16. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Minerals are elements other than carbon, hydrogen, oxygen, and nitrogen –They play a variety of roles in the body 21.18 Connection: Essential minerals are required for many body functions

17. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Table 21.18

18. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Food labels provide important nutritional information about packaged foods 21.19 Connection: What do food labels tell us? Figure 21.19

19. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Choice of diet may reduce the risk of cardiovascular disease and cancer 21.20 Connection: Diet can influence cardiovascular disease and cancer Figure 21.20 BEHAVIORAL RISK FACTORS UNAVOIDABLE RISK FACTORS Fatty diet Lack of exercise Smoking High blood cholesterol High blood pressure CARDIOVASCULAR DISEASE Aging Family history Being male

20. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Table 21.20

21. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings A sound diet supplies –enough raw materials to make all the macromolecules we need –the proper amounts of prefabricated essential nutrients –enough kilocalories to satisfy our energy needs