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6.1 Digestion
Question | Answer |
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Why is the digestion of large food molecules essential? | - Food is made up of polymers: polysaccharides, proteins, and lipids. - Hydrolysis needed to break food into monomers. - So that food can be small and soluble to be absorbed into cells lining the gut. - Food then used as building blocks. |
What is the role of enzymes in digestion? | - Enzymes increase the rate of digestion at body T (By speeding up reaction and decreasing activation energy) |
What is the function of the stomach? | - Chemical digestion of food (proteins by pepsin) - Short-term food storage - Immune defense (acidity) |
What is the function of the small intestine? | - Digestion (enzymes secreted from wall of small intestine and pancreas + bile) (bile works with pancreatic lipase) - Absorption (structure adapted for this purpose) |
What is the function of the large intestine? | - Absorption of: i. liquids ii. minerals |
Contrast absorption with assimilation. | Order: absorption must happen before assimilation. - One is transport of materials across cell membrane and the other is the use of materials. - Absorption: move substances through cell membrane or cell layers - Assimilation: nutrients built into org |
How is the structure of the villus related to its role in absorption and transport of the products of digestion? | Phy.: - twists and folds, microvilli (micros. folds on epith. cells) incr. SA - Sin. layer of epith. ce. redu diffusi. dis. Bio: - Mito. prov. ener. for AT of nutr. acr. CG - Mucus protec. epith. and lub. - Sup. of blo. main. CG - Lacte. close to s |