Biotyping Based On Amino Acid Metabolism Flashcards
What are amino acids use for?
-building proteins
An amino acid is built under what 3 structures?
- side change
- Amino group
- acid
What can unneeded proteins be used for?
-can be converted into amino acids through hydrolysis
What is amination?
-converts an organic acid (made from cell resp or fermentation) to an amino acid
NH3 (ammonia) + organic acid > amino acid
What is transamination?
- when a cell has too much of one amino acid and not enough of another amino acid, it is balanced during this reaction
- Process: an amino acid and an organic acid react, resulting in a different amino acid and a different organic acid
What is deamination?
-converts excess amino acids into organic acids
Amino Acid > Organic acid + Ammonia (NH3)
Why is urea created?
-its how humans package their excess nitrogen after deamination because ammonia is toxic to human cells
What happens during a urease reaction?
Reaction: Urea > Urease (enzyme)> Ammonia and CO2
- makes ammonia for amination (make amino acids)
- raises pH
- damages human cells
What does the MIO medium test for?
Motility, indole production, ornithine decarboxylation
The MIO medium is used to differentiate bacteria in which family?
-enterobacteriaceae
What is the role of Ornithine Decarboxylase in bacteria when placed in the MIO medium?
- The MIO medium contains a small amount of glucose (0.1%)
- Bacteria that ferment it will release acids that cause the pH indictator in the media to turn purple to yellow
- After the glucose is completely consumed, the bacteria will then use the amino acids in the media as a source of energy.
- Some bacteria can breakdown the amino acid ornithine using the enzyme ornithine decarboxylase
- when ornithine is broken down this way, its converted to putrescine> raise pH> turn purple
How do some bacteria release the molecule indole?
- some bacteria possess the enzyme tryptophanase.
- this enzyme breaks down the amino acid tryptophan and releases the molecule indole
How is Indole indicated in the MIO medium?
- by adding Kovacs reagent after the bacteria have grown
- indole is made from the amino acid tryptophan
-Pink > red indicates the presence of indole
What does the M in MIO stand for and how is it tested?
-Motility
- Non-motile bacteria will grow only near the stab line.
- motile bacteria are able to swim and spread out from the stab line due to MIO media having a relatively low concentration of agar
Nutrient gelatin medium is used to identify species within which bacterial family?
Enterobacteriaceae
What is the main ingredient in nutrient gelatin?
- a derivative of the collagen proteins found in animals, including people
- collagens are strong, fibrous proteins found in connective tissues
How is gelatin used in Nutrient gelatin?
- when added to a liquid medium, the unfolded collagen proteins thicken the medium
- remain liquid at room temp
What are gelatinases?
Enzymes that can digest denatured collagen
What are Collagenases
Enzymes that can digest collagen in its denatured (gelatin) or non-denatured state
What is the function of urease?
-breakdown urea into ammonia and carbon dioxide
Urea Agar is used to identify species in which bacterial family?
Enterobacteriaceae
What does a + and - result look like in a Urease reaction test?
- when the Enzyme urease converts urea to ammonia (raises pH) causes the indicator to turn fuchsia
What are 2 advantages urease gives a bacterial species
- essential in the colonization of the host organism
- maintainance of bacterial cells in tissues
Classify each processes as catabolic or anabolic
1) protease reaction
2) Amination
3) deamination
4) urease reaction
5) tryptophanase reaction
1) catabolic
2) anabolic
3) catabolic
4) catabolic
5) catabolic
What do bacterial cells need to build amino acids?
1) carbon based molecules of the right size
2) source of fixed nitrogen
3) source of energy
For amination reactions to occur, what kind of energy must be expended?
-ATP or other high energy compounds, NADPH
Excess amino acids in bacterial cells can also be used as?
- can be converted into organic acids, and further broken down to release useable energy
- this energy is often captured to build ATP
What is the molecular structure of Urea?
-Characteristics: less toxic to human cells than ammonia
