Decarboxylases Pg 99-101 NOT DONE Flashcards
Twenty different amino acids occur naturally in proteins. Each amino acid molecule has a ________, _________, and a _______ attached to its first carbon atom
Carboxyl group (-COOH)
Amino group (-NH2)
Radical (side chain of atoms)
In order to breakdown amino acids, some microorganisms produce a specific enzyme which will split an amino acid by removing the carboxyl group and yielding ________. This enzyme is _________.
Carbon dioxide gas. Decarboxylase .
What is the microbial degradation of proteinaceous materials with the formation of foul-smelling products such as amines.
Putrefaction
_________ & ________ are formed by the decarboxylation of lysine and ornithine
Cadaverine and putrescine
Decarboxylase equation
Decarboxylase
Amino acid ——-————> Amine + CO2 gas
Which genera of bacteria are difficult to distinguish from each other? How to we test to tell them apart?
- Klebsiella, Enterobacter, and Citrobacter
-telling them apart by testing their abilities to decarboxylate different amino acids
What else are these tests useful for?
Useful for distinguishing species. The amino acids most useful are lysine, arginine, and ornithine.
How do we tests for the decarboxylation of lysine, a broth which contains the amino acid lysine?
A fermentable carbohydrate (basal medium), and bromcresol purple indicator, is inoculated.
Before incubation, what is layered on top of the broth to create an anaerobic condition.
Sterile mineral oil
During incubation at 37 degrees Celsius, the bacteria first ferment the _________ creating an ______.
Carbohydrate
Acid
If the bacteria can produce lysine decarboxylase, the lysine will be decarboxylated producing CO2 gas and leaving the lysine amine which does what to the pH?
Raises the pH above 6.3
Bromcresol purple is what color above pH 6.3
An what color below that pH?
Arginine and ornithine tests are similar
Is purple (basic)
And yellow (acidic) below the pH
