Biology 20 Digestive System Williams

Front 1

accessory organs

Back 1

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

Back 2

enzyme in saliva that breaks down starch into simpler sugars

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acid

Back 3

responsible for turning on the enzyme for digestion of proteins

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catalyst

Back 4

a chemical that speeds up a chemical reaction but is not used up in the reaction

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hydrolysis

Back 5

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

Back 6

a thick liquid formed by mixing food with gastric juice in the stomach

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digestive tract

Back 7

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

Back 8

a smooth, lump like mass of food rolled by the tongue to aid swallowing

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macromolecule

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a large, complex assembly of organic molecules; four categories are, Carbohydrates, Lipids, Proteins, and Nucleic acids.

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liver

Back 10

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

Back 11

sugar that can be hydrolysized into two monosaccharide sub units

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monosaccharide

Back 12

simple sugar that cannot be hydrolyzed into simpler sugars; fructose, glucose and galactose

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lower esophageal (cardiac) sphincter

Back 13

a muscular ring between the esophagus and the stomach that controls the movement of food into the stomach

Front 14

dehydration synthesis

Back 14

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

Back 15

the organ that stores bile produced by the liver

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gastrin

Back 16

stomach hormone that stimulates the secretion of hydrochloric acid and pepsinogen from glands in the stomach

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homeostasis

Back 17

the tendency of the body to maintain a relatively constant internal environment

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lipases

Back 18

enzyme that catalyzes the hydrolysis of triglycerides into glycerol and fatty acids

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bioavailability

Back 19

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

Back 20

protein molecule that acts as a catalyst to increase the rate of a reaction

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pancreas

Back 21

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

Back 22

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

Back 23

protein-digesting enzyme secreted in the stomach; remains inactive until hydrochloric acid is present

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peristalsis

Back 24

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

Back 25

a complex carbohydrate containing many simple sugars linked together; examples include starch, cellulose, and glycogen.

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peptide bonds

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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

Back 27

substance on which an enzyme acts

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triglyceride

Back 28

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

Back 29

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

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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

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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

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activated by the enzyme enterokinase, serves to break down polypeptides

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protein

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organic macromolecule assembled from subunits of amino acids

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erepsin

Back 34

completes chemical digestion of polypeptides by creating amino acids from short chains

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pyloric sphincter

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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

Back 36

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

Back 37

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

Back 38

the first 25cm of the small intestine; important site of chemical digestion of chyme from the stomach

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microvilli

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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

Back 40

enzyme that hydrolyses the bonds between nucleotides in nucleic acids

Front 41

secretin

Back 41

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)

Back 42

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

Back 43

a hormone which slows the peristalsis, allowing more time for fat digestion