Catalase Test

Catalase Activity on Substrate Based On Gas Pressure Production Rate Name of the Class Author’s Name Date Enzymes are organic compounds which act as catalysts and speed up biological reactions in biological organisms. They are not destroyed or changed during the reaction but rather they are used over and over again to catalyze many more reactions. Their activity may be affected and altered by factors such as temperature, substrate concentration, enzyme concentration and Ph.

If the catalase enzyme is present in the organism being tested then when in the presence of hydrogen peroxide (H2O2), the enzyme will convert the solution to water and oxygen, this can be observed bubbling of the organism when hydrogen peroxide is added to the test tube. EMB agar is both a selective and differential media; it is selective for gram-negative cells, in that when a gram-positive culture is plated there will be no colonies after incubation because the eosin and methylene dyes prevent the growth of gram-positive organisms, the

Staphylococcus epidermis produces the enzyme catalase. In the PEA Agar, a catalase test was performed which showed that the organism produced catalase. Staphylococcus epidermis is not a mannitol fermenter. Mannitol fermenting organisms grow on the Mannitol Salt Agar. The unknown organism is not a mannitol fermenter because it did not grow on the Mannitol Salt Agar.

What do nitrifying bacteria do? The nitrifying bacteria turn nitrogen into usable nitrates, which the plants can take up. 2. Explain the process of ammonification.

Crystal violet was then added for 60 seconds before being washed off with water. The mordant, Gram’s Iodine, was added for another 60 seconds before getting washed off with water. The heat fixed smear was then washed with 95% alcohol until the wash ran clear, leading to the final step of adding Safranin for 45 seconds before being rinsed with water. The slide was finally blot dyed with bibulous paper before it was placed under a microscope to observe the color and shape of the bacterium. 2.2 Litmus Milk Reaction

The compounds tested in included the unknown, Calcium Nitrate, Calcium Chloride, Calcium Carbonate, Sodium Chloride, Potassium Chloride, Magnesium Chloride, and Ammonium Chloride. The next test was the pH test. In this test, the aqueous solutions from the flame tests were used again. A piece of pH paper was dipped into the aqueous solutions, a different piece for each solution. The ensuing coloration of the paper was compared to the pH scale and the

Being able to identify unknown microbes from systematic testing is what makes the field of microbiology so important, especially in infectious disease control. Using the testing procedure laid out by the microbiology field we are able to identify unknown bacteria present in our everyday lives, and along the way learn a lot about their characteristics that separate them from other types of bacteria. Being able to do this is vital in order for us to understand why microbes are present in certain places, how they are able to grow and what restricts their growth, that way they can be combatted if necessary. These techniques for determining unknowns are also important for isolating and testing infectious disease microbes in order to prevent spreading. Another important aspect of being able to identify unknown microbes is the

Starch amylase testing was equally unsubstantial since the only amylase producing bacteria was ruled out after Gram staining. Unknown #10’s negative citrate test result was also unhelpful because E. coli is citrate negative and P. vulgaris is a variable citrate producer that can also be citrate negative. H2S production in the Kligler’s Iron Agar test ultimately proved that Unknown #10 was Proteus vulgaris. P. vulgaris is the only assigned bacteria that produces H2S, so when a black precipitate obscured the yellow butt of the Kligler’s Iron Agar slant, E. coli was ruled out. Not only did the H2S product confirmed that Unknown #10 was P. vulgaris, it confirmed P. vulgaris’ motility.

Since unknown organism B was gram positive, I had decided my first biochemical test would be the Catalase test per lab manual. The result of the catalase test after adding H2O2 was immediate air bubbles. The second biochemical test performed on organism B was starch agar per lab manual. Once the reagent was added I did not

The Another medium used was MAC, it is used to isolate and differentiate gram-negative organisms and it is a pink, dusty rose color. Lastly, the Citrate Slant is a green color and it was used as a differential test to examine enzymes. The media were inoculated at 37°C for 48 hours, then it was observed to determine the

Introduction In class, a series of experiments were performed that pertained to the enzyme known as catalase, which converts hydrogen peroxide into oxygen. Due to peroxide being toxic to the tissues of both plants and animals, both possess the enzyme catalase, which breaks into two non-toxic compounds: water and oxygen gas. Enzymes are proteins that react to certain substrates to create a product, and continue doing so afterwards. Methods and Materials To test reactions between catalase and hydrogen peroxide, groups of three to four people were formed.

It is secreted by the oxyntic cells in the gut which are found within the oxyntic glands of the stomach lining. The substance is colourless yet remarkably corrosive, and is therefore able to be the primary digester of food in an individual4. The liquid’s pH level is a highly dangerous, yielding 1, though it may vary slightly due to its molarity (# of molesliters of solution), but nevertheless is deemed a strong acid. When the two are combined, CO2 is released, and so the their rate of reaction may be measured by the pressure of the resulting gas5.

Then, tests are performed to determine if the products of aerobic and anaerobic respiration are present in the flasks. The citric acid cycle consists of a series of chemical reactions used by all aerobic organisms to release stored energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins into carbon dioxide and chemical energy in the form of ATP (Biology). The tests detect the presence of carbon dioxide and ethanol. Carbon dioxide should be present irrespective of the type of respiration taking place, but ethanol is present only if fermentation has occurred. Another factor that can indicate whether fermentation occurred or cellular respiration occurred is the amount of glucose utilized during incubation.

The reaction that occurs can be investigated via the adding of the liver extract which contains the arginase to urea concentrations and distilled water. The amount of urea formed is determined via spectrophotometric analysis α-INPP. The urea produced was known via the color reaction with the α-INPP, it is the reagent used for the colorimetric determination of urea. (Barry J, et al. 1984). The red color formed when the α-INPP is reacted with the urea, is sensitive to light thus it is photo labile.

This carbolic acid is what gives Lifebuoy the distinctive red colour and the strong medical