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43 Cards in this Set
- Front
- Back
accessory organs |
Refers to the pancreas, liver and gall bladder, because their role is vital in digestion but they directly are not apart of the digestive track |
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amylase |
enzyme in saliva that breaks down starch into simpler sugars |
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acid |
responsible for turning on the enzyme for digestion of proteins |
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catalyst |
a chemical that speeds up a chemical reaction but is not used up in the reaction |
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hydrolysis |
chemical reaction in which the addition of a water molecule cleaves a macromolecule into subunits; one hydrogen atom is bonded to one subunit and a hydroxyl group is bonded to the other subunit, breaking a covalent bond in the macromolecule |
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chyme |
a thick liquid formed by mixing food with gastric juice in the stomach |
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digestive tract
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In animals a long tube that extends from the mouth to the anus, through which food moves and is broken down into simpler compounds, that are used for energy, growth, and cell repair |
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bolus
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a smooth, lump like mass of food rolled by the tongue to aid swallowing |
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macromolecule |
a large, complex assembly of organic molecules; four categories are, Carbohydrates, Lipids, Proteins, and Nucleic acids. |
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liver |
organ found in the abdomen that performs hundreds of functions as an accessory organ of the digestive system, including the secretion of bile to digest fats; other functions include plasma protein production, blood detoxification, and glycogen storage |
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disaccharide |
sugar that can be hydrolysized into two monosaccharide sub units |
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monosaccharide |
simple sugar that cannot be hydrolyzed into simpler sugars; fructose, glucose and galactose |
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lower esophageal (cardiac) sphincter |
a muscular ring between the esophagus and the stomach that controls the movement of food into the stomach |
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dehydration synthesis
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chemical reaction that results in the formation of a covalent bond between two subunit molecules by the removal of an -OH (Hydroxyl) group from one subunit and a hydrogen from the other, making a water molecule |
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gall bladder |
the organ that stores bile produced by the liver |
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gastrin |
stomach hormone that stimulates the secretion of hydrochloric acid and pepsinogen from glands in the stomach |
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homeostasis
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the tendency of the body to maintain a relatively constant internal environment |
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lipases |
enzyme that catalyzes the hydrolysis of triglycerides into glycerol and fatty acids |
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bioavailability
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the amount of a nutrient that a person absorbs from a source, rather than the total amount actually in the source |
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enzyme |
protein molecule that acts as a catalyst to increase the rate of a reaction |
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pancreas |
large gland in the abdomen that secretes digestive enzymes into the small intestine, as well as bicarbonate to neutralize hydrochloric acid from the stomach. |
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inhibitor
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molecule that attaches to an enzyme and reduces its availability to bind substrate; competitive and non competitive are its two classes |
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pepsin |
protein-digesting enzyme secreted in the stomach; remains inactive until hydrochloric acid is present |
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peristalsis
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a wave like series of muscular contractions and relaxations of the circular and longitudinal muscles that surround the various parts of the digestive track; aiding the movement of food. |
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polysaccharide
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a complex carbohydrate containing many simple sugars linked together; examples include starch, cellulose, and glycogen.
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peptide bonds |
the bond formed by the joining of carboxyl group of one amino acid to the amino group of another amino acid |
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substrate |
substance on which an enzyme acts |
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triglyceride |
high energy and organic molecule composed of one glycerol molecule and three fatty acids; main component of fats and oils. |
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villi |
finger like projections on the inside of the small intestine, increasing the surface area aiding in the absorption of nutrients. |
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essential amino acid |
refers to the 9 out of 20 amino acids that come from the diet because the body can’t synthesize them
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nucleic acid |
macromolecule formed from a long chain of nucleotide subunits, each consisting of a five-carbon simple sugar, a nitrogen containing base, and a phosphate group; DNA and RNA.
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trypsin |
activated by the enzyme enterokinase, serves to break down polypeptides |
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protein |
organic macromolecule assembled from subunits of amino acids |
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erepsin |
completes chemical digestion of polypeptides by creating amino acids from short chains |
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pyloric sphincter |
muscular ring that acts as a valve between the stomach and the first part of the small intestine (duodenum), controlling the passage of food out of the stomach |
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small intestine |
length of the digestive tract comprised of the duodenum, jejunum, and ileum; main function is to complete the digestion of macromolecules and to absorb their component subunits |
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large intestine |
portion of the digestive system comprised of the caecum, colon, rectum, and anal canal; main function is to concentrate and eliminate waste materials |
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duodenum |
the first 25cm of the small intestine; important site of chemical digestion of chyme from the stomach |
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microvilli |
microscopic projection found along exposed ell surfaces that greatly increase the surface area of the cell; found on the villi of the small intestine and on the membranes of certain cells |
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nuclease |
enzyme that hydrolyses the bonds between nucleotides in nucleic acids
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secretin |
A hormone released into the bloodstream by the duodenum (in response to acidity) to stimulate secretion by the liver and pancreas |
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CCK (cholecystokinin)
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A hormone produced principally by the small intestine in response to the presence of fats, causing contraction of the gallbladder, release of bile, and secretion of pancreatic digestive enzymes |
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enterogasterone |
a hormone which slows the peristalsis, allowing more time for fat digestion |