Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Developmental biology wikipedia , lookup
Chemical biology wikipedia , lookup
Synthetic biology wikipedia , lookup
Nutritional anthropology wikipedia , lookup
History of biology wikipedia , lookup
List of nutrition guides wikipedia , lookup
History of molecular biology wikipedia , lookup
Nutrition transition wikipedia , lookup
Animal Nutrition Human Digestion Regents Biology 2006-2007 What do animals need to live? Animals make energy using: food oxygen food Animals build bodies using: food for raw materials amino acids, sugars, fats, nucleotides ATP O2 ATP energy for synthesis Regents Biology How do animals get their food? suspension feeding Regents Biology fluid feeding substrate feeding bulk feeding Regents Biology Different diets; different lives All animals eat other organisms Herbivores eat mainly plants gorillas, cows, rabbits, snails Carnivores eat other animals sharks, hawks, spiders, snakes Omnivores eat animals & plants cockroaches, bears, raccoons, humans humans evolved as hunters, scavengers & gatherers Regents Biology Getting & Using Food Ingest taking in food Digest mechanical digestion breaking up food into smaller pieces chemical digestion breaking down food into molecules small enough to be absorbed into cells enzymes intracellular digestion Absorb absorb across cell membrane diffusion active transport Eliminate undigested material passes out of digestive system Regents Biology extracellular digestion Digestive systems Everybody’s got one! Regents Biology Human digestive system Regents Biology Swallowing (& not choking) Epiglottis flap of cartilage closes trachea (windpipe) when swallowing food travels down esophagus Peristalsis involuntary Regents Biology muscle contractions to move food along Ingestion Mouth mechanical digestion teeth breaking up food chemical digestion saliva amylase enzyme digests starch mucin slippery protein (mucus) protects soft lining of digestive system lubricates food for easier swallowing buffers neutralizes acid to prevent tooth decay anti-bacterial chemicals kill bacteria that enter mouth with food Regents Biology mouth break up food digest starch kill germs moisten food Regents Biology Stomach Functions food storage can stretch to fit ~2L food disinfect food HCl = pH 2 kills bacteria chemical digestion pepsin enzyme breaks down proteins But the stomach is made out of protein! What stops the stomach from digesting itself? mucus secreted by stomach cells protects Regents Biology stomach lining mouth break up food digest starch kill germs moisten food stomach kills germs break up food digest proteins store food sphincter sphincter Regents Biology Coevolution of parasite & host Ulcers Colonized by H. pylori Used to think ulcers were caused by stress tried to control with antacids inflammation of stomach H. pylori now cure with antibiotics Regents Biology inflammation of esophagus H. pylori Now know ulcers caused by bacterial infection of stomach Free of H. pylori inflammatory proteins (CagA) cytokines cell damaging proteins (VacA) helper T cells neutrophil cells white blood cells Revolutionizing healthcare 2005 Nobel prize in medicine J. Robin Warren Barry Marshall Regents Biology Small intestine Function chemical digestion major organ of digestion & absorption absorption through lining over 6 meters! small intestine has huge surface area = 300m2 (~size of tennis court) Structure 3 sections duodenum = most digestion jejunum = absorption of nutrients & water ileum = absorption of nutrients & water Regents Biology Duodenum 1st section of small intestines acid food from stomach mixes with digestive juices from: pancreas liver gall bladder Regents Biology Pancreas Digestive enzymes digest proteins trypsin, chymotrypsin digest starch amylase Buffers neutralizes acid from stomach Regents Biology mouth break up food digest starch kill germs moisten food pancreas produces enzymes to digest proteins & starch Regents Biology stomach kills germs break up food digest proteins store food Liver Function produces bile bile stored in gallbladder until needed breaks up fats act like detergents to breakup fats bile contains colors from old red blood cells collected in liver = iron in RBC rusts & Regentsfeces Biology makes brown mouth break up food digest starch kill germs moisten food liver produces bile - stored in gall bladder break up fats pancreas produces enzymes to digest proteins & starch Regents Biology stomach kills germs break up food digest proteins store food Absorption by Small Intestines Absorption through villi & microvilli finger-like projections increase surface area for absorption Regents Biology mouth break up food digest starch kill germs moisten food liver produces bile - stored in gall bladder break up fats pancreas produces enzymes to digest proteins & starch Regents Biology stomach kills germs break up food digest proteins store food small intestines breakdown food - proteins - starch - fats absorb nutrients Large intestines (colon) Function re-absorb water use ~9 liters of water every day in digestive juices > 90% of water reabsorbed not enough water absorbed diarrhea too much water absorbed constipation Regents Biology You’ve got company! Living in the large intestine is a community of helpful bacteria Escherichia coli (E. coli) produce vitamins vitamin K; B vitamins generate gases by-product of bacterial metabolism methane, hydrogen sulfide Regents Biology mouth break up food digest starch kill germs moisten food liver produces bile - stored in gall bladder break up fats pancreas produces enzymes to digest proteins & carbs Regents Biology stomach kills germs break up food digest proteins store food small intestines breakdown food - proteins - starch - fats absorb nutrients large intestines absorb water Appendix Vestigial organ Regents Biology Rectum Last section of colon (large intestines) eliminate feces undigested materials extracellular waste mainly cellulose from plants roughage or fiber masses of bacteria Regents Biology Different diets; different bodies Adaptations of herbivore vs. carnivore teeth length of digestive system number & size of stomachs Regents Biology Teeth Carnivore sharp ripping teeth “canines” Herbivore wide grinding teeth molars Omnivore both kinds of teeth Regents Biology Length of digestive system Herbivores & omnivores long digestive systems harder to digest cellulose (cell walls) bacteria in intestines help Carnivores short digestive systems protein easier to digest than cellulose Regents Biology Eating a balanced diet What happens if an animal’s diet is missing an essential nutrient? deficiency diseases scurvy — vitamin C (collagen production) rickets — vitamin D (calcium absorption) blindness — vitamin A (retinol production) anemia — vitamin B12 (energy production) kwashiorkor — protein Regents Biology Vegetarian diets Need to make sure you get enough protein 20 amino acids to make protein 12 amino acids humans can produce 8 we have to eat = “essential amino acids” Grains (like corn) have 6 (missing 2) Beans (like soybean & red beans) have 6 (missing different 2) mix beans & grains for complete group of amino acids rice & beans taco/tortilla & beans tofu & rice peanut butter & bread Regents Biology Feedback: Maintaining Homeostasis Balancing glucose levels in blood depress appetite pancreas insulin cells take up glucose from blood liver takes up glucose for storage liver releases glucose to blood Regents Biology glucagon pancreas stimulate hunger Any Questions?? Regents Biology 2006-2007