Chapter 41 1 Understand the necessity of nutrition to animals lacking the ability to undergo photosynthesis a Animals must consume food for energy and organic molecules in order to assemble new cells tissues and molecules b Diet must satisfy chemical energy for cellular process essential nutrients and organic building blocks for micromolecules i All depend on chemical energy to produce ATP 2 Be familiar with the four types of essential nutrients for animals a Essential Amino Acids i Animals require 20 amino acids and can synthesize about half from molecules in their diet ii The remaining amino acids the essential amino acids must be obtained from food in preassembled form iii Come from mea eggs cheese b Essential fatty acids i Obtained from diet unsaturated fatty acids ii Linoleic acid obtained from seeds grains veggies c Vitamins organic b c contain carbon such as carbs lipids proteins vitamins i Assist in regulating body processes ii Required in smaller amounts iii Crucial for building and maintaining bones and tissues iv Support immune system v DO NOT supply energy to our bodies rather help extract energy from food vi 13 are essential for humans 1 Thiamine from pork peanuts whole grains vii Vitamin D deficiency can lead to Rickets Disease softening of bones 1 Vitamin D from egg yolk milk sunlight viii All B vitamins and C are water soluble ix Vitamin A D K E not soluble KADE d Minerals inorganic do not contain carbon like water i Regulate fluid and energy production ii Essential for bone and blood health iii Remove harmful metabolic by products iv Two types major and trace v Too much can upset homeostatic balance vi Arginine e What does it mean for a nutrient to be essential i Must be obtained from food ii Molecules required by cells that cannot be made by metabolic processes so must be obtained by diet f How do humans typically receive these essential nutrients g What are some of the major problems associated with a lack of i Diet essential nutrients i Deficiencies lead to deformities diseases and possibly death ii Undernutrition diet that doesn t provide enough chemical energy 1 Causes using up of stored fat carbohydrates 2 Breaks down own protein loses in muscle mass 3 Suffer protein deficiency of brain iii Golden Rice strain of rice that has beta carotene which is converted to vitamin A helps vision 3 Understand the four stages of food processing a Ingestion b Digestion i Act of eating i Breaking down of food i Uptake of nutrients by cells c Absorption d Elimination i Rid of undigested materials e Why break down proteins instead of just using them i Proteins have similar function but come in different amino acid sequence so they are broken to amino acid are then reformed f What protects all of our molecules from digestion i Intracellular digestion 1 Food particles are engulfed by phagocytosis 2 Food vacuoles containing food fuse with lysosomes containing hydrolytic enzymes ii Extracellular digestion 1 Breakdown of food outside of cells 2 Occurs in compartments that are continuous with the outside of the animal s body 4 Know the differences in food processing between animals with a gastrovascular cavity and those with an alimentary canal a Gastrovascular cavity i Are in animals with simple body plans ii Functions in both digestion and distribution of nutrients iii One opening for ingestion and elimination iv Foods digested throughout the body v Cells are only a thin layer away from digestion absorption vi Ex flatworm i Digestive tube with 2 openings mouth and anus ii AKA complete digestive tract iii Carries out digestion and absorption in a stepwise fashion iv Moves in a single direction b Alimentary canal v Ex earthworm bird grasshopper 5 Thoroughly understand the organs and accessory glands of the human digestive system a Be able to differentiate between mechanical and chemical digestion i Mechanical ii Chemical digestion membrane 1 includes chewing and increases surface area of food 1 splits food into small molecules that can pass the iii Enzymatic hydrolysis splits bonds in molecules with addition of water b For each digestive organ be aware of the types of hydrolytic enzymes present as well as the source of the hydrolytic enzymes i Mammalian accessory glands 1 Salivary 2 Pancreas 3 Liver 4 Gallbladder ii Mouth oral cavity 1 Salivary glands lubricate food 2 Carbs are broken down HERE 3 Teeth break down food 4 Saliva starts chemical digestion and protects oral cavity 5 Enzyme Amylase found in saliva hydrolyzes starch and glycogen into smaller 6 Mucus found in saliva is what protects oral cavity 7 Tongue ships food into ball called Bolus iii Pharynx opens into two passages esophagus and trachea 1 Esophagus connects to the stomach 2 Trachea to your windpipe 3 A flap called epiglottis covers the glottis trachea passage a If this swallow reflex fails food reaches trachea and causes choking coughing 4 Peristalsis contractions that move bolus to stomach iv Stomach stores food and secretes gastric juice 1 Converts meal to acid chyme 2 Sphincters prevent chyme from entering esophagus and regulates entry to small intestine a Acidic chyme to esophagus causes acid reflux b A sphincter at the opening of the stomach to the small intestine releases only a small amount of chyme into the small intestine at a time 3 Juice hydrochloric acid has pH of 2 this denatures proteins in food which increases exposure of their peptide bond 4 These bonds are attacked by juice called protease or by pepsin protein digesting enzyme 5 Proteins are broken down here 6 HCl and Pepsin both form in the Lumen 7 Mucus protects stomach lining from gastric juice 8 Chief cells release pepsin into the lumen in an inactive form called pepsinogen 9 HCl converts pepsinogen into pepsin by exposing its 10 Parietal cells secrete hydrogen and chloride ions into 1 Capillaries and veins carry nutrient rich blood AWAY 2 This vein goes directly to liver 3 Then blood travels to the heart and other organs 4 Allows liver to regulate the distribution of nutrients and 5 allows liver to remove toxic shit If stomach isn t closed fully can cause back flow of chyme heartburn 6 Sphincters are between stomach and small intestine active site lumen v SIDE NOTE from villi a Allows chyme to pass vi Small intestine largest section of alimentary canal 1 1st portion is duodenum a where chyme mixes with other juices b final steps of digestion take place here 2 breaks down all 4 macromolecules vii Pancreas 1 Aides in chemical digestion by
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