STUDY GUIDE CH 41

STUDY GUIDE CH 41.1 List and briefly describe the three dietary categories of animals. Herbivores: eat mainly autotrophs (plants) Carnivores: eat other animals Omnivores: regularly consume animals as well as plants Name the three nutritional needs that must be met by an animal’s diet. (*) Carbon Nitrogen ATP Define essential nutrients. Describe the four classes of essential nutrients. ESSENTIAL Amino Acids: Protein, 20 AA required and only able to synthesize about half from molecules in diet. Essential Fatty Acids: Storage of energy, certain unsaturated fatty acids that must be obtained from the diet Vitamins: organic molecules required 13 essential vitamins Minerals: simple inorganic nutrients, needed in small amounts Distinguish among undernourishment, over nourishment, and malnourishment UNDERNOURISHMENT: result of a diet that consistently supplies less chemical energy then the body requires (use up stored fat and carbs, breat down own proteins, lose muscle mass, suffer deficiency of the brain OVERNOURISHMENT: causes obesity, which results from excessive intake of food energy with the excess stored as fat MALNOURISHMENT: long-term absence from the diet of one or more essential nutrients (deformities, diseases, and death) Describe the four main stages of food processing.(*) INGESTION: act of eating +Suspension feeders: sift small food particles from the water +Substrate feeders: live in or on their food source +Find feeders: suck nutrient-rich fluid from a living host +Bulk feeders: eat relatively large pieces of food DIGESTION: Process of breaking food down into molecules small enough to absorb (Chemical and Mechanical) ABSORPTION: uptake of nutrients by body cells ELIMINATION: passage of undigested material out of the digestive compartment Compare intracellular and extracellular digestion. Food Vacuoles Hydrolysis Pinocytosis To avoid digesting their own cells and tissues, most organisms conduct digestion unspecialized compartments. 7. Distinguish between a complete digestive tract and a gastrovascular cavity. A complete digestive tract has a mouth and an anus (alimentary canal), a gastrovascular cavity has one opening acting as the mouth and the anus Describe the common processes and structural components of the mammalian digestive system.(*) Alimentary canal Accessory glands (Salivary glands, pancreas, liver, gallbladder) Peristalsis: rhythmic contractions of muscles in the wall of the canal, pushes food along the digestive tract Sphincters: regulate the movement of material between compartments 9) Name three functions of saliva. Cleanses the mouth Dissolves food chemicals so they can be tasted Moistens food and aids in compacting food into a bolus Contains enzymes that begin chemical breakdown of starch Compare where and how the major types of macromolecules are digested and absorbed within the mammalian digestive system. Food is broken down by our teeth in the oral cavity (mouth). The salivary glands deliver saliva to lubricate the food and to expose the smaller particles of food to salivary amylase which breaks down glucose polymers. The tongue shapes the food into a bolo to help us swallow. So first it goes down the pharynx and then down the esophagus. Explain why pepsin does not digest the stomach lining. The ingredients of gastric juice are kept inactive until they are released into the lumen (cavity) of the stomach. The stomach lining protects against self-digestion by secreting mucus. 12. Explain how the small intestine is specialized for digestion and absorption. The small intestines are well adapted for absorbing nutrients during digestion by: being very long, having villi and microvilli that increase surface area, using muscular contractions to move and mix food, and receiving and housing digestive enzymes and bile that help the breakdown of food. 14. Describe the major functions of the large intestine. *Recover water that has entered the alimentary canal *Feces are stored in the rectum *Feces pass through the rectum and exit via the anus *Cecum aids in the fermentation of plant material *Appendix plays a minor role in immunity 15. Relate variations in dentition and length of the digestive system to the feeding strategies and diets of herbivores, carnivores, and omnivores. (*) HERBIVORES: Don't need sharp teeth Scissor like incisors to cut up plant matter Big flat molars and premolars to grind down plant material CARNIVORES: Long pointy canine for biting and killing prey Sharp pre-molars to cut/rip flesh Molars to grind food OMNIVORES: Incisors for cutting vegetable material Some sharp teeth as well 16. Describe the roles of symbiotic microorganisms in vertebrate digestion. Helps herbivores digest plants by breaking down cellulose.