Chapter 10 The Digestive System (Defs.) Flashcards
A very large molecule made up of smaller molecules that are linked together.
Macromolecule
The sum total of all of the chemical reactions that occur in an organism.
Metabolism
Provide materials to build cell membranes. Provide quick energy for use by cells.
Ex. glucose, fructose, lactose, maltose, starch, glycogen, cellulose.
Carbohydrates
Provide structure and support for blood cells, body tissues, and muscles. Aid in muscle movements, such as contraction. Act as catalysts to speed up chemical reactions in the cells. Provide immunity against infection and disease.
Transport ions in cell membranes.
Ex. insulin, hemoglobin, collagen, antibodies, enzymes.
Proteins
Contain the organism’s genetic information. Direct the organism’s growth.
Ex. deoxyribonucleic acid (DNA), ribonucleic acid (RNA).
Nucleic acids
A simple sugar with 3 to 7 carbon atoms.
Monosaccharide
A sugar made up of 2 monosaccharide molecules.
Disaccharide
A large molecule made up of many linked monosaccharide molecules.
Polysaccharide
A polysaccharide made up of glucose units.
Glycogen
An organic compound that does not dissolve in water, such as fat and oil.
Lipid
A building block of protein.
Amino acid
A bond that holds together the amino acids in a protein.
Peptide bond
A linear chain of several amino acids linked by peptide bonds.
Polypeptide
A chemical reaction in which water breaks apart macromolecules into smaller molecules.
Hydrolysis
A protein molecule that helps speed up important chemical reactions in the body.
Enzyme
What are the four stages of food processing? With description?
Ingestion - The taking in or eating of food.
Digestion - The breakdown of food by mechanical and chemical processes into molecules small enough for cells of the body to absorb.
Absorption - The transport of the products of digestion from the digestive system into the circulatory system, which distributes them to the rest of the body.
Elimination - The removal of undigested solid waste matter from the body.
The physical breakdown of large pieces of food into smaller pieces in the mouth by the action of teeth, beak, or other similar structures, and churning motions in the stomach.
Mechanical digestion
The chemical breakdown of nutrient molecules into smaller molecules by enzyme action.
Chemical digestion
A pouch at the beginning of the large intestine that receives waste material from the small intestine.
Cecum
The muscular tube through which food passes from the mouth to the stomach.
Esophagus
A wave-like series of muscular contractions in the esophagus.
Peristalsis
A ring muscle that controls the entrance to the stomach; normally closed to prevent the acidic contents of the stomach from backing up into the esophagus, but it relaxes to allow each bolus of food to enter the stomach.
Esophageal sphincter
A burning sensation in the throat or chest that occurs when small amounts of acidic liquid escape from the stomach and move up the esophagus into the throat; also known as heartburn.
Acid reflux
A mixture of hydrochloric acid, salts, enzymes, water, and mucus that is produced by glands in the stomach to help digest food.
Gastric juice
A thick liquid produced in the stomach and made of digested food combined with gastric juice.
Chyme
An enzyme in gastric juice that helps break down proteins into polypeptides.
Pepsin
A muscular valve at the lower end of the stomach that controls the flow of chyme; when closed, it keeps food in the stomach; when open, it allows chyme to flow into the small intestine.
Pyloric sphincter
A short, wide U-shaped section of the small intestine into which food passes from the stomach.
Duodenum
Finger-like projections lining the surface of the small intestine that increase the surface area to improve the absorption of nutrients.
Villi (singular villus)
The fine brush-like projections that cover the surface of each villus in the lining of the small intestine.
Microvilli (singular microvillus)
The portion of the small intestine that follows immediately after the duodenum.
Jejunum
The portion of the small intestine that follows immediately after the jejunum.
Ileum
A greenish-yellow fluid secreted by the liver that helps digest fat.
Bile
An accessory organ to the digestive system that secretes pancreatic fluid into the duodenum; enzymes in pancreatic fluid chemically digest carbohydrates, lipids, and proteins.
Pancreas
An accessory organ to the digestive system that stores bile between meals.
Gall bladder
An accessory organ to the digestive system that produces bile, which aids in the digestion of fats; largest internal organ of the body.
Liver
The region of the digestive system where leftover matter from the colon collects as feces.
Rectum
A by-product of the breakdown of hemoglobin (the protein that carries oxygen in the blood); gets secreted into the bile in the liver; responsible for the brown colour feces.
Bilirubin
A sore in the lining of the stomach or duodenum, most commonly caused by infection with the bacterium Helicobacter pylori.
Peptic ulcer
The general name for a group of diseases that cause inflammation in the intestines.
Inflammatory bowel disease (IBD)
A form of inflammatory disease that can affect any part of the alimentary canal from the mouth to the anus.
Crohn’s disease
A form of inflammatory disease that attacks the colon.
Ulcerative colitis
Inflammation of the liver, most commonly caused by a virus.
Hepatitis
The irreversible replacement of healthy liver tissue with non-functioning scar tissue; most commonly caused by excessive alcohol intake or hepatitis.
Cirrhosis
A condition in which the body is unable to use glucose for energy.
Diabetes
