1. Chapter 41: Animal Nutrition By Josh Ivanir

2. Overview Three main categories that animals fall in: -Herbivores: eat mainly autotrophs (plants and algae) ex. Gorillas, cattle -Carnivores: eat other animals ex. Sharks,hawks -Omnivores: regularly consume animals as well as plants or algae ex. Humans, Bears Most animals are also opportunistic feeders, foods that are outside their main dietary category when these foods are available. All animals consume bacteria along with other types of food.

3. http://upload.wikimedia.org/wikipedia/commons/thumb/5/50/Male_gorilla _in_SF_zoo.jpg/220px-Male_gorilla_in_SF_zoo.jpg http://www.richardbealblog.com/wp- content/uploads/2011/12/cattle-5.jpg http://www.saltwater-aquarium- online-guide.com/image- files/shark.jpg http://images.nationalgeographic.com/wpf/media- live/photos/000/006/cache/red-tailed- hawk_681_600x450.jpg http://srtherapies.com/files/images/eating-pizza.jpg Herbivores Carnivores Omnivores

4. For any animal, a nutritionally adequate diet must satisfy three nutritional needs: fuel (chemical energy) which is converted into ATP to power cellular processes. Organic building blocks, such as organic carbon and organic nitrogen, to synthesize a variety of organic molecules Essential nutrients, which are required by cells and must be obtained from dietary sources

5. Concept 41.1 Homeostatic mechanisms manage an animal’s energy budget The flow of energy into and out of an animal′s body can be viewed as a “budget”. Mostly all of an animal′s ATP generation is based on the oxidation of energy, carbohydrates, proteins, and fats, in cellular respiration. Monomers of any of these substances can be used as fuel. Animals “burn” proteins only after exhausting their supply of carbohydrates and fats. Fats are rich in energy. Biosynthesis occurs when an animal takes in more calories than it needs to produce ATP. In humans, the liver and muscle cells store energy in the form of glycogen, a polymer made up of many glucose units. Glucose is an important fuel for cells.

7. When fewer calories are consumed, fuel is taken out of storage depots and oxidized. This causes the animal to lose weight. Most healthy people, even if they are not obese, have enough stored fat to sustain them through several weeks of starvation. Caloric imbalance: Undernourishment: If the diet of a human or other animal is chronically deficient in calories. body begins breaking down its own proteins for fuel, muscles begin to decrease in size, and the brain can become protein– deficient. Overnourishment: Excessive food intake. Stores excess fat molecules instead of using them.

8. Fat cells from the abdomen of a human

9. Obesity Now recognized as a major global health problem by The World Health Organization. In the United States, the percentage of obese (very overweight) people has doubled to 30% in the past two decades. Obesity contributes to a number of health problems, including the most common type of diabetes, cancer of the colon and breasts, and cardiovascular disease that can lead to heart attacks and strokes. Scientists are able to control appetite-regulating hormones. Inheritance is a major factor in obesity. Defective genes can contribute to issues in weight loss.

10. Appetite- Regulating Hormones

11. Mouse on Left has defective gene that produces Leptin.

12. Concept 41.2: An animal′s diet must supply carbon skeletons and essential nutrients An animal′s diet must also supply all the raw materials needed for biosynthesis, in addition to providing fuel for ATP production. An animal must obtain organic precursors (carbon skeletons) from its food to grow, maintain itself, and reproduce. Animals can fabricate a great variety of organic molecules—carbohydrates, proteins, and lipids. Animal′s diet must also supply essential nutrients.

13. Essential Nutrients: materials that must be obtained in preassembled form because the animal′s cells cannot make them from any raw material. Malnourished: an animal whose diet is missing one or more essential nutrients. Four classes of essential nutrients: – essential amino acids – essential fatty acids – Vitamins – minerals

14. Essential Amino Acids An amino acid that an animal cannot synthesize itself and must be obtained from food. Eight amino acids are essential in the human adult. Animals require 20 amino acids to make proteins. protein deficiency: form of malnutrition caused by insufficient amounts of one or more essential amino acids. Proteins in animal products are “complete,” which means that they provide all the essential amino acids in their proper proportions. Most plant proteins are “incomplete”.

15. Protein deficiency in Haitian boy called Kwashiorkor

16. Essential Amino Acids from a Vegetarian Diet

17. Essential Fatty Acids Certain unsaturated fatty acids that animals cannot make. Fatty Acids have double bonds. Deficiencies are rare.

18. Vitamins An organic molecule required in the diet in very small amounts. Vitamins serve primarily as coenzymes or parts of coenzymes. Vitamin deficiencies can cause severe problems. 13 vitamins essential to humans have been identified. Grouped into two categories: – water–soluble vitamins – fat–soluble vitamins

19. Vitamin requirements in Humans

20. Minerals In nutrition, a chemical element other than hydrogen, oxygen, or nitrogen that an organism requires for proper body functioning. Humans and other vertebrates require relatively large quantities of calcium and phosphorus for the construction and maintenance of bone. Most people eat more salt than needed

21. Mineral Requirements for Humans

22. Concept 41.3: The main stages of food processing are ingestion, digestion, absorption, and elimination Ingestion: A heterotrophic mode of nutrition in which other organisms or detritus are eaten whole or in pieces. Organic material in food consists largely of proteins, fats, and carbohydrates in the form of starch and other polysaccharides. Cannot use these macromolecules directly for two reasons: – polymers are too large to pass through membranes and enter the cells of the animal. – macromolecules that make up an animal are not identical to those of its food. Digestion: The process of breaking down food into molecules small enough for the body to absorb.

23. Stages of Food Processing

24. enzymatic hydrolysis: The process in digestion that splits macromolecules from food by the enzymatic addition of water. Absorption: The uptake of small nutrient mol–ecules by an organism′s own body; the third main stage of food processing, following digestion. Elimination: The passing of undigested material out of the digestive compartment.

25. Digestive Compartments Intracellular digestion: The joining of food vacuoles and lysosomes to allow chemical digestion to occur within the cytoplasm of a cell. Begins after a cell engulfs food by phagocytosis or pinocytosis. Extracellular digestion: The breakdown of food outside cells. Occurs within compartments that are continuous with the outside of the animal′s body. Gastrovascular cavity: An extensive pouch that serves as the site of extracellular digestion and a passageway to disperse materials throughout most of an animal′s body. Animals with relatively simple body plans have a digestive sac with a single opening. Complete digestive tract: A digestive tube that runs between a mouth and an anus; also called an alimentary canal. An incomplete digestive tract has only one opening.

26. alimentary canals

27. Concept 41.4: Each organ of the mammalian digestive system has specialized food–processing functions The mammalian digestive system consists of the alimentary canal and various accessory glands that secrete digestive juices into the canal through ducts. Peristalsis: Rhythmic waves of contraction of smooth muscle that push food along the digestive tract. Sphincter: A ring like valve consisting of modified muscles in a muscular tube, such as a digestive tract; closes off the tube like a drawstring. Salivary glands: Exocrine glands associated with the oral cavity. The secretions of salivary glands contain substances to lubricate food, adhere together chewed pieces into a bolus, and begin the process of chemical digestion. Pancreas: A gland with dual functions: The nonendocrine portion secretes digestive enzymes and an alkaline solution into the small intestine via a duct; the endocrine portion secretes the hormones insulin and glucagon into the blood. Liver: The largest organ in the vertebrate body. The liver performs diverse functions, such as producing bile, preparing nitrogenous wastes for disposal, and detoxifying poisonous chemicals in the blood. Gallbladder: An organ that stores bile and releases it as needed into the small intestine.

28. Human Digestive System

29. The Oral Cavity, Pharynx, and Esophagus During chewing, teeth of various shapes cut, smash, and grind food, making it easier to swallow and increasing its surface area. Oral cavity: The mouth of an animal. Oral Cavity triggers a nervous reflex that causes the salivary glands to deliver saliva through ducts to the oral cavity. Humans secrete more than a liter of saliva each day. Saliva contains a slippery glycoprotein called mucin. Salivary amylase: A salivary gland enzyme that hydrolyzes starch and glycogen. Bolus: A lubricated ball of chewed food. During swallowing, the tongue pushes a bolus to the back of the oral cavity and into the pharynx. Pharynx: An area in the vertebrate throat where air and food passages cross; in flatworms, the muscular tube that protrudes from the ventral side of the worm and ends in the mouth. Epiglottis: A cartilaginous flap that blocks the top of the windpipe, the glottis, during swallowing, which prevents the entry of food or fluid into the respiratory system. Esophagus: A channel that conducts food, by peristalsis, from the pharynx to the stomach.

31. The Stomach An organ of the digestive system that stores food and performs preliminary steps of digestion. Gastric juice: A digestive fluid secreted by the stomach. Converts a meal to acid chyme. Gastric juice includes hydrochloric acid and the enzyme pepsin.

32. The Stomach

33. The Small Intestine The major organ of digestion and absorption. Acid chyme from the stomach mixes in the duodenum with intestinal juice, bile, and pancreatic juice. Diverse enzymes complete the hydrolysis of food molecules to monomers, which are absorbed into the blood across the lining of the small intestine. Hormones help regulate digestive juice secretions.

35. The Large Intestine Aids the small intestine in reabsorbing water and houses bacteria, some of which synthesize vitamins. Feces pass through the rectum and out the anus.

37. Concept 41.5: Evolutionary adaptations of vertebrate digestive systems are often associated with diet Some Dental Adaptations A mammal′s dentition is generally correlated with its diet. Mammals have specialized dentition that best enables them to ingest their usual diet.

39. Stomach and Intestinal Adaptations Herbivores generally have longer alimentary canals than carnivores, reflecting the longer time needed to digest vegetation.

40. Symbiotic Adaptations Many herbivorous animals have fermentation chambers where symbiotic micro– organisms digest cellulose.

41. Works Cited All Images and information from Campbell biology