9 16 13 Kin 110 class notes Gumball machine human example ATP CP fat protein Question of the day o If the gastrointestinal system is like a washing machine what molecules are laundry products GI system o Digest use store food o Don t need to know the parts oral cavity esophagus stomach o Complex polymers to single nutrients o Efficiently absorb the nutrients o Exclude antinutrients toxins bacteria Point of digestion o Food polymers usually solid but not necessarily single nutrients in a watery aqueous solution what kind of apple Honey crisp water and simple sugars can only absorb single nutrients Chunnel between England and France o Food not in body as it passes through gastrointestinal system o Prevents infection by separating food from the rest of the body Mouth o Liquification saliva and mechanical disruption chewing o So liquefied sea of smaller pieces o Do you have to chew your food to digest it No eat that powerbar whole Salivary amylase starch o Break bonds between simple sugars o Leave food in mouth for a min gets sweeter Food in mouth causes o Muscle contraction in stomach o Some stomach cells produce hydrochloric acid burns hole in clothing in seconds o Muscles transverse oblique A Acid lowers pH of food from 7 2 very acidic o Kills bacteria viruses protozoen o Thick mucus layered on stomach protects the rest of the body from damage B Low pH proteins unwinds them o Goes from a clump to a string of spaghetti o Need surface area to break down food o Starch digestion ends because salivary amylase denatured C activates pepsin enzyme that makes protein amino acids o Mechanical action Fat in food forms large drops clumps together o Example salad dressing o Grinding action of stomach smaller droplets Stomach grinding action turns large fat drops small droplets o Exit of food from stomach pylorus Slow down Exit of food through pylorus o Fiber makes you feel more full o Fat stays in stomach longer more full o Stress pylorus stays closed longer o Eat differently before a game than a practice o Pylorus opens more slowly In small intestine immediate problem with acidity of food o Baking soda from pancreas neutralizes acidic food neutrality o sodium bicarbonate o secreted into small intestine o same as baking soda What what bile made in liver coats fat droplet cholesterol prevents them from forming big drops o stored in the gallbladder bile makes large fat drops into small bile droplets o removed gallbladder hard to digest fatty foods o lipases fat smaller components o laundry detergent enough bile can be used as laundry detergent Does the same thing bile absorbed and recycled back to large intestine o recycled back to liver liver makes new bile then to gallbladder starts again
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