Module 7 Intro
1. Module 7 Intro
1.28. Module Glossary
Module 7—The Digestive and Respiratory Systems
Module Glossary
anabolic: the metabolic process that builds larger molecules from smaller molecules
catabolic: the metabolic process in which materials are broken down
catalyze: to increase the rate of reaction
chemoreceptor: detects chemical stimuli in the environment and turns stimuli into electrical nerve impulses that signal parts of the body to respond accordingly
chyme: the partially digested, semi-fluid mass of food that is forced from the stomach into the small intestine
cilia: small, hairlike organs on the surface of some cells, particularly cells lining the upper respiratory tract
Their wavelike movements waft particles of dust and debris outward; Latin for “eyelash.”
dehydration synthesis: an enzyme-controlled composition reaction in which compounds are formed by the removal of water
emphysema: an obstructive respiratory disorder in which the walls of alveoli break down and lose elasticity
There are fewer individual air sacs as walls break down, thus reducing the surface area for gas exchange. A loss of elasticity makes exhaling more difficult.
feedback inhibition: the process by which the accumulated end product of a biochemical pathway stops the synthesis of that product
hydrolysis: the decomposition of a compound in a reaction by using water
pepsin: a digestive enzyme found in gastric juice that catalyzes the breakdown of protein to peptides
pepsinogen: the inactive precursor to pepsin formed in the chief cells of the mucous membrane of the stomach and converted to pepsin by hydrochloric acid during digestion
peristalsis: the wavelike series of muscular contractions and relaxations in structures such as the esophagus
sphincter: a ringlike muscular structure that normally maintains constriction of a natural body passage or orifice and that relaxes as required by normal physiological functioning
substrate molecule: a molecule that an enzyme interacts with chemically
For example, the enzyme sucrase only binds to the substrate molecule of sucrose.