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10 Cards in this Set
- Front
- Back
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what is digestion? |
digestion is the process in which large molecules are hydrolysed by enzymes to produce smaller molecules that can be absorbed and assimilated |
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what is a monounsaturated fat acid? |
fatty acid that possesses a carbon chain with a single double bond |
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polyunsaturated fatty acid? |
fatty acid that possesses carbon with many double bonds |
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explain starch digestion |
1. food is taken into the mouth and chewed by the teeth. this breaks it into small pieces, giving it a large surface area 2.saliva enters the mouth from the salivary glands and is throughly mixed with the food during chewing 3.saliva contains salivary amylase. this starts the hydrolysing any starch in the food to maltose. 4.the food is swallowed and enters the stomach, where the conditions are acidic. this denatures the salivary amylase and prevents further hydrolysis of starch. |
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starch digestion continued. |
5.after a time the food passes into the small intestine, where it mixes with the secretion from the pancreas called pancreatic juice. 6.pancreatic juice contains pancreatic amylase. This continues the hydrolysis of starch to maltose. alkaline salts are produced by the pancreas and the intestinal wall to neutralise the stomach acid. 7.muscles in the intestinal wall push the food along the small intestine. the lining of the small intestine produces maltase. this hydrolyses the maltose into a-glucose(alpha) |
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explain sucrose digestion |
in natural foods sucrose is usually contained within the cells and these must be physically broken down, in order to release it. the sucrose pass through the stomach and into the small intestine, whose epithelial lining proudest enzyme sucrose. |
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explain maltose digestion |
amylase hydrolyses the alternate glycosidic bond of the starch molecule to produce the disaccharide maltose. maltose is produced by the lining intestine. |
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function&adaptions of organs in digestive system |
salivary glands- pass secretions via a tube into mouth. adaption-secretions contain amylase an enzyme that breaks down starch into maltose
oesophagus-carries food from mouth to stomach. adaption- muscular wall which contracts in waves to move food. |
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function&adaptions of organs in digestive system |
liver- produces bile. adaptions- bile helps the break down of fat. stomach- stores/digests food makes acid. churns food with juices to make thick paste chyme. adaption- glands in stomach wall produce enzyme (proteases) small intestine- large food broken down to smaller ones. absorbed into blood. adaption-villi and microvilli increase the surface area for absorption. |
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function&adaptions of organs in digestive system |
pancreas- produces a secretion called pancreatic juice. adaption-thin walled tube large intestine-water from undigested food and digested juices in absorbed in to blood. adaption- contains proteases, topazes and amylase. rectum- faeces are stored here before periodically being removed via the anus in a process called egestion. |
