1. Module 7 Intro

1.28. Module Glossary

In This Module

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.