C hapter 41: A nimal N utrition

1. Chapter 41:Animal Nutrition By Camilo Tapia-Urdaneta, Elena Lam, and Xoujun

2. Animals An animals diet must supply chemical energy, organic raw materials, and essential nutrients. Herbivores mainly eat plants. carnivores eat other animals. omnivores eat plants and other matter. There are many aquatic animals that are suspension feeders, sifting small particles from the water. Substrate feeders tunnel through their food, eating as they go. fluid feeders suck nutrient-rich fluids from a living host. Most animals are bulk feeders eating as they go. Extra tip: if you were to jog a mile a few hours after lunch, which stored fuel would you probably tap? > You would tap the muscle and liver glycogen

3. Homeostatic Mechanisms glucose regulation: Vertebrates store excess calories as glycogen in the liver and muscles and as fat. These energy stores may be tapped when an animal expends more calories than it consumes. Blood glucose level is maintained within a relatively narrow range by a negative feedback mechanism. caloric imbalance: undernourished animals have diets deficient in calories. Overnourished animals consume more calories than they need. Obesity is a very serious problem In the united states, where lack of exercise and fattening foods make an unhealthy combination. Obesity is strongly determined by genes. The problem of maintaining a healthy weight partly stems from our evolution past, when fat hoarding may have been important for survival. Extra info: individuals who’s diet consists of primarily of corn would likely become malnourished

4. Supplying Carbon Skeletons and Essential Nutrients Carbon skeletons are required in biosynthesis. Essential nutrients must be supplied in preassembled form. Malnourished animals are missing one or more essential nutrients in their diet. Something that is required for nutrition is vitamins. Vitamins are organic molecules required in small amounts, They are either water-soluble or fat-soluble. Minerals are also very important for nutrition, they are inorganic nutrients, usually required in small amounts. nutrients required = healthy body Extra tip: the symbiotic microbes that help nourish a ruminant live mainly in specialized regions of the stomach

5. Food processing in animals involves ingestion (act of eating), digestion (enzymatic breakdown of the macromolecules of food into their monomers), absorption (the uptake of nutrients by body cells), and elimination (the passage of undigested materials out of the body in feces). Digestive compartments In intracellular digestion, food particles are engulfed by endocytosis and digested within food vacuoles. Most animals use extracellular digestion, with enzymatic hydrolysis occurring outside cells in a gastrovascular cavity or alimentary canal. Extra tip: which of the following organs is incorrectly paired with its feeding mechanisms? > Large intestine – bile production. Main Stages of Food Processing:Ingestion,Digestion,Absorption, andElimination

6. Mammalian Organs and Functions The stomach stores food and secretes gastric juice, which converts a meal to acid chyme. Gastric juice includes hydrochloric acid and the enzyme pepsin. Small intestine is the major organ of digestion and absorption. Acid chyme from the stomach mixes in the duodenum with the intestinal juice, bile, and pancreatic juice. Diverse enzymes complete the hydrolysis of food molecules to monomers, which are absorbed into the blood and lymph across the lining in the small intestine. Hormones help regulate digestive juice secretion. 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. oral cavity, pharynx, and esophagus: food is lubricated and digestion begins in the oral cavity, where teeth chew food into smaller particles that are exposed to the salivary amylase, initiating the break down of glucose polymers. The pharynx is the intersection leading to the trachea and esophagus. The esophagus conducts food from the pharynx to the stomach by involuntary peristaltic waves. Extra tip: the mammalian trachea and esophagus both open into the rectum. Extra tip: which of the following enzimes has the lowest pH optimum? >trypsin

7. Evolutionary Adaptation Association With Diet • dental adaptations: a mammals dentition is generally correlated with its diet. In particular, mammals have specialized dentition that best enables them to ingest their usual diet. • Stomach and intestinal adaptations: herbivores generally have longer alimentary canals then carnivores, reflecting longer time needed to digest vegetation. • Symbiotic adaptations: many herbivore animals have fermentation chambers where symbiotic microorganisms digest cellulose. • Extra info: our oral cavity, with its dentition, is most functionally analogous to an earthworm’s gizzard

8. The end