Match each of the ollowing enrymes to their respective biochemical eaction A. Am
ID: 210925 • Letter: M
Question
Match each of the ollowing enrymes to their respective biochemical eaction A. Amylase B. Cysteine desulfiuran C. Lipase D. Tryptophanase E. Urease 31. Indole prodaction 2 A Sarch hydrolysis . Hydrogen Sulfide production Ammonia production Fat hydrolysis 34. 35. Numbers 36 through 40 Match the name ofthe chemicals below to approprate- A. Alpha Naphtho B. Dimethyl alpha Naphthylamine C Sulphanilic acid D. Potassium bydroxide E. Ferric Chloride 36.- 37,- 38. Bamm's reagent A Barritt's reagent B CNitrate reagent A Nitrate reagent Reagent to detect Phenylpymuvic acid In biooxidation/fermentation experiments, glucose broth, lactose beoth, and mannitol be were used. They all contain Durham tubes and phenol rod 41. The function of the Durham tube is to Provide oxygen for the reaction Retain the pH indicator Trap gas produced as a result of fermentation reaction Contain the enzyme required for the reaction A. D.Explanation / Answer
31-35. Amylase is an enzyme that digests starch. It hydrolyses starch to disaccharide maltose composed of two glucose. They act on alpha 1, 4 and alpha 1,6 glycosidic bond. There are two types of amylase- alpha, beta-amylase. Alpha amylase is seen in saliva and is pancreas. Beta amylase is seen in bacteria, yeast and some plants.
Cysteine disulphurase catalyses the conversion of cysteine to alanine and releases hydrogen sulphide due to removal of sulfhydryl and amino groups from cysteine. This is the basis of the sulphur indole motility (SIM test). Bacteria that have this enzyme break down cysteine to form H2S which is seen as a black precipitate due to reaction with iron.
Lipase is an enzyme that breaks down lipids. It breaks down dietary fats into fatty acids. It is released by pancreas in small intestine to break down fats. Some amount of lipase is also seen in saliva and stomach. High amount of lipase causes hyperlipisemia.
Tryptophanase breaks down amino acid tryptophan. Tryptophan is broken down into indole, pyruvate and ammonia. It is a pyridoxal phosphate containing enzyme that requires K+ ions.
Urease enzyme breaks down or hydrolyses urea to ammonia and carbon dioxide. It is produced by various bacteria as a virulence factor. It is found in intestinal microflora, plants (soybean, jackbean) etc.
Right Options:
31. D (Tryptophanse) Indole production
32. A (Amylase) Starch hydrolysis
33. B (cysteine desulphurase) Hydrogen sulphite production
34. E (Urease) Ammonia production
35. C (Lipase) Fat hydrolysis
36-40. Alpha naphthol (C10H7OH) is a component of Barritt reagent A which is prepared in ethanol. Barritts reagent A and B are used in Voges-Proskauer test for detection of acetoin production by bacterial culture. It helps in identification of gram negative Enterobactericiae. The culture is grown in MR-VP medium. MR negative bacteria produce initial pyruvic acids from glucose metabolism which are decarboxylated to form neutral acetyl methylcarbinol (acetoin). As a result, there us decreased acidity in the medium, increasing the pH to neutrality (pH 6.0 or above). MR positive bacteria however, keep forming acid and reduce the pH as they cannot form acetoin. Acetoin and 2, 3- butanediol in presence of atmospheric oxygen and alkali are oxidized to diacetyl, which react with creatine to produce a red colour. Acetoin reacts with alpha naphthol to form red color. Potassium hydroxide is present in Barritt's reagent B that provides alkaline conditions.
Nitrate reduction test: Nitrate reagent A contains sulphanilic acid while reagent B contains alpha napthylamine solution. Nitrates are broken down by bacteria to nitrite in presence of zinc. Nitrite reacts with sulfanilic acid to form a nitrite-sulfanilic acid, which then reacts with dimethyl - naphthylamine to form a red precipitate, prontosil.
Phenylpyruvic acid test detects the ability to produce deaminase enzyme. Deaminase removes an amino group from phenylalanine to produce a phenylpyuruvic acid (PPA). PPA reacts with ferric chloride producing a green colored compound. Thus, the medium turns dark green.
Right Option is:
36. A (Alpha napthol) Barritt’s reagent A
37. D (Potassium hydroxide) Barritt’s reagent B
38. C (Sulphanilic acid) Nitrate Reagent A
39. D (dimethyl alpha naphthylamine) Nitrate reagent B
40. E (Ferric chloride) Reagent to detect phenylpyruvic acid.
41. Durhams tube are small tubes that are placed upside down in another test tube containing media. Durhams tubes are used to detect gas production by microorganism. The gas produced by the organism is seen as bubbles in the Durhams tubes. Bacteria produce gas due to fermentation of the sugars present in the medium.
Right option is C. Trap the bubbles as a result of fermentation reaction.