Microbiology Lab 5-12 Phenylalanine Deaminase

Questions and Answers

What is the purpose of the Phenylalanine Deaminase lab?

To detect organisms which are capable of producing phenylalanine deaminase

What type of media was used for the phenylalanine deaminase lab?

Phenylalanine slants

What chemical reagent was added to the phenylalanine deaminase lab and why was it added?

FeCl3 or Ferric chloride. It helps determine if phenylalanine deaminase is produced by being a visual indicator.

When was FeCl3 added?

Second day of lab or after incubation Signup and view all the answers

What does the result to the left mean if the left image is yellow?

Negative result which means no color change and phenylalanine deaminase was not produced. Signup and view all the answers

What are the ingredients for this lab?

Yeast extract, phenylalanine, small amount of salt, and agar Signup and view all the answers

How long does this lab need to be incubated for?

24 hours Signup and view all the answers

Why is FeCl3 added to the agar?

Ferric chloride is added because if phenylpyruvic acid was produced, it will produce a dark green color. Signup and view all the answers

Is this lab selective or differential reagent?

Differential reagent because it needs a visual, which is FeCl3. Signup and view all the answers

What is the function of phenylalanine deaminase?

Phenylalanine deaminase removes the amino group. Signup and view all the answers

Which genera of bacteria can produce this enzyme?

Proteus, Morganella, and Providencia Signup and view all the answers

What disease is associated with these genera?

UTIs and opportunistic infections Signup and view all the answers

What is the name of the amino acid provided in the agar?

Phenylalanine Signup and view all the answers

What is deamination?

Catalyze or removal of amino group. It requires oxygen and has no effect on pH. Signup and view all the answers

What is decarboxylation?

Anaerobic process that removes the carboxyl group and releases carbon dioxide, changing pH. Signup and view all the answers

Phenylalanine is broken down to?

Ammonia and phenylpyruvic acid Signup and view all the answers

Explain what a positive result looks like and what it means?

A positive result will have a dark green slant. This means the organism was able to produce phenylalanine deaminase. Signup and view all the answers

What other experiment will we perform with deaminase activity?

Lysine Iron Agar Signup and view all the answers

Why isn't mineral oil added?

Because trying to remove the amino acid. Not a carboxyl group and need oxygen. Signup and view all the answers

Can an organism still grow in this media but test negative for phenylalanine deaminase?

True Signup and view all the answers

What is the end product that is being detected for this lab?

Phenylpyruvic acid Signup and view all the answers

Why are enzymes or biochemical reactions needed?

Enzymes and biochemical reactions are used as tools to identify microbes. Signup and view all the answers

What is enzyme composition?

Protein (organic macromolecules) Signup and view all the answers

Enzymes interact with what?

Substrates and any molecule involved in the chemical reaction. Signup and view all the answers

What are the functions of enzymes?

Catalyze reactions, digestion, and buildup. Signup and view all the answers

What is the suffix for enzyme names?

-ase Signup and view all the answers

What is protein catabolism?

Proteins which are organic macromolecules; building blocks also known as amino acids. Signup and view all the answers

What does an amino acid structure contain?

An amino group, a carboxyl group, and a side chain. Signup and view all the answers

What biochemical group is being removed from the phenylalanine deaminase lab?

Amino group Signup and view all the answers

How would a positive result look like and what does it mean?

The top slant is positive for phenylalanine deaminase. It means that it produced phenylalanine deaminase enzyme. Signup and view all the answers

What media was used for this lab?

Fish tail (using loop) Signup and view all the answers

How does the biochemical reaction of phenylpyruvic acid look like?

The formation of phenylpyruvic acid indicates successful deamination. Signup and view all the answers

Explain what is happening in the biochemical reaction for phenylalanine deaminase lab.

Phenylalanine deaminase media tests the ability of an organism to produce the enzyme deaminase. Signup and view all the answers

Study Notes

Phenylalanine Deaminase Lab Overview

Aimed at detecting organisms capable of producing phenylalanine deaminase.
Utilizes phenylalanine slants as culture media.

Reagents and Procedures

Ferric chloride (FeCl3) is added post-incubation to serve as a visual indicator for enzyme production.
Incubation lasts for 24 hours on the surface of the slant before adding FeCl3.
A negative result shows no color change (yellow), indicating no phenylalanine deaminase production.

Ingredients and Chemical Processes

Media consists of yeast extract, phenylalanine, salt, and agar.
Deamination involves the removal of the amino group (-NH2) from phenylalanine, producing ammonia and phenylpyruvic acid.
Decarboxylation, an anaerobic process, removes the carboxyl group (-COOH) and can lower pH.

Interpretation of Results

A dark green slant result signifies a positive test, indicating phenylalanine was deaminated to phenylpyruvic acid, confirmed by FeCl3 reaction.
Organisms can grow in the media but may test negative for phenylalanine deaminase.

Associated Bacteria and Diseases

Genera able to produce the enzyme include Proteus (associated with UTIs), Morganella, and Providencia which causes opportunistic infections.

Additional Information

Enzymes are proteins that catalyze biochemical reactions, often ending with the suffix "-ase."
Enzymatic reactions require specific substrates and facilitate processes such as digestion and metabolism.
Amino acid structures consist of a central carbon, an amino group, a carboxyl group, and a variable side chain.

Further experiments involving deaminase activity can be performed using Lysine Iron Agar.
Mineral oil is not added since it results in inhibiting necessary oxygen during the deamination process.

Understanding Phenylalanine Pathway

The biochemical reaction transforms phenylalanine into phenylpyruvic acid, highlighting the organism's enzymatic capability.
The end product of interest is phenylpyruvic acid, essential for identifying microbial characteristics in this lab.

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Description

This quiz focuses on the Phenylalanine Deaminase lab, specifically designed to assess the understanding of its purpose, the media used, and the reagents involved. It includes crucial terminology and definitions that are vital for microbiology studies.