BIOL 206 Study Guide - Midterm Guide: Bromothymol Blue, Cytochrome C Oxidase, Phosphate
Document Summary
The oxidase test identifies organisms that produce the enzyme cytochrome oxidase. Cytochrome oxidase participates in the electron transport chain by transferring electrons from a donor molecule to oxygen. The oxidase reagent contains a chromogenic reducing agent, which is a compound that changes color when it becomes oxidized. If the test organism produces cytochrome oxidase, the oxidase reagent will turn blue or purple within 15 seconds. Hydrogen peroxide is a potent oxidizing agent that can kill cells; because of this, any cell that uses oxygen or can live in the presence of oxygen must have a way to get rid of the peroxide. One of those ways is to make catalase. Catalase is the enzyme that breaks hydrogen peroxide (h2o2) into h2o and o2. Catalase producing bacteria (catalase positive) releases oxygen which forms bubbles The coagulase test identifies an organism that produces the exoenzyme coagulase. Coagulase causes the fibrin of blood plasma to clot.
