Question

the reagent used in the oxidase test is a: acid - base buffer chromogenic reducing agent protein stain ph indicator question 6 (1 point) the urea hydrolysis test uses phenol red as: a protein substrate a ph indicator a reducing agent a nutrient source

Explanation:

• For the oxidase test: The oxidase test aims to detect the presence of cytochrome c oxidase. The reagent used is a chromogenic reducing agent. It gets oxidized by the enzyme (if present) and changes color.
• For the urea hydrolysis test: Phenol red is a pH - indicator. When urea is hydrolyzed by urease (produced by some bacteria), ammonia is released. Ammonia makes the medium alkaline. Phenol red changes color in response to this pH change (from yellow to pink in alkaline conditions).

Answer:

• First question: Chromogenic reducing agent
• Second question: A pH indicator