MIP302 Final Lab Exam (from Turned in Labs)correctly answered graded A+ 2023/2024

MIP302 Final Lab Exam (from Turned in Labs) In which environments will microaerophiles grow and not grow (Done in Lab) - correct answer Growth in ambient air incubator and Candle Jar No growth in GasPak Jar In which environments will Facultative anaerobes grow and not grow (Done in Lab) - correct answer Growth in ambient air incubator, candle jar, and GasPak Jar In which environments will Obligate anaerobes grow and not grow (Done in Lab) - correct answer No growth in Ambient air incubator and candle jar Growth in GasPak Jar Catalase Test Results - correct answer bubbles: positive no bubbles: negative Cytochrome Oxidase Test Results - correct answer Colorless: negative Dark blue color change: Positive Carbohydrate Fermentation-PR Broth Results -Lactose Fermentation - correct answer Hot pink: Negative gas production-negative ferment lactose Yellow: Positive for gas production-positive for lactose fermentation Nitrate and Nitrite Reductase Test Results - correct answer Colorless:Inconclusive after addition of Nitrate A and B Colorless (after zinc added): + for nitrate and nitrite reductase Red (after nitrate A and B added): + for nitrate and - for nitrite Red (after zinc added): negative for nitrate and nitrite reductase What compound is formed when oxygen in the broth is reduced? - correct answer H2O (Water) Why was C. perfringens grown in thioglycollate broth instead of TSB? - correct answer Because it is an obligate anaerobe. Thioglycollate broth contain sodium thioglycolate, which decreases free oxygen in the media, which creates an anaerobic environment Imagine that you have a tube of water containing methylene blue dye. You inoculate the broth with 'active, dry' baker's yeast. The bakers yeast contains trehalose, which the yeast uses to grow in the water, using aerobic respiration. As the yeast cells respire, the water turns from blue to colorless. Why? - correct answer As the yeast cells respire, the water turns from blue to colorless because the dye is initially oxidized because it hasn't received electrons from the yeast (inactive yeast), then as the yeast cells respire the dye gains electrons from the yeast and turns colorless Under aerobic conditions, some yeast cells use aerobic respiration and produce carbon dioxide. Under anaerobic conditions, these same yeast cells ferment carbohydrates to produce alcohol and carbon dioxide. These yeasts are unusual, because they are one of the very few eukaryotic organisms that are classified as __________ ___________, based on their oxygen requirements - correct answer Facultative anaerobe Human RBCs produce catalase. Based on this information, what do you think happens when hydrogen peroxide is used to clean a wound? Why? - correct answer Based on the fact that human RBCs produce catalase, when hydrogen peroxide is used to clean a wound it interacts with the catalase and the hydrogen peroxide converts it into water and oxygen, which will form bubbles An oxidase test has turned slightly pink after sitting on the bench for 10 minutes. Is this a positive result? Why or why not? - correct answer No, this would not be a positive result because the oxidase test needs to be observed within 3 minutes. As the test sits on the bench for 10 minutes, it is absorbing O2 from the environment and makes the sample think it was oxidized Phenol red is incorporated in PR carbohydrate broth to detect the presence of __________ which is produced during ___________ of the carbohydrate in the broth - correct answer -Lactic Acid -Fermentation