Lab 9 Handout and Post Lab Questions Essay

644 WordsDec 19, 20143 Pages
Lab 9: Electron Transport Chain Experiment 1: Oxidase Assay for Respiration Table 1: Assay Results Filter Paper Section Colony Color Change? Oxidase Positive or Negative? Exp. 1 1 Yes Positive Exp. 2 1 No Negative Exp. 3 1 No Negative Control 1 No Negative Post-Lab Questions: 1. Which bacterial plates contained oxidase positive bacteria? Sink only. Which plates contained oxidase negative bacteria? Shoe, Phone, and Control Did both of the colonies from each plate show the same color change? No Why or why not? Different types of bacteria are rubbed on each side of a petri dish. If there is more bacteria put on one side that side is going to grow more. Just because they are in the same petri dish doesn’t mean that they…show more content…
Sink only 2. Which plates contained catalase negative bacteria? Shoe and Phone 3. Did the colonies from each plate show the same reaction? No Why or why not? There are separate types of bacteria in each section and they may not grow at the same rate. How can you interpret this? For example, in my dish with the sink and shoe, there were no traces of bacteria on the shoe side but a lot of bacteria on the sink side. If the bacteria were to have multiplied and spread due to being in the same dish, it would have given me a positive result on the shoe side which it didn’t. 4. Were any controls used in this experiment? The control portion of a petri dish was used but we did not test to see if reacted with the hydrogen peroxide, so there was technically no control in this case. 5. What reaction would you expect when performing a negative control in the catalase assay? The reaction I would expect for a negative control would be no reaction in the catalase assay. No bubbles should form. 6. What reaction would you expect when performing a positive control in the catalase assay? I would expect a reaction to occur and bubbles to form. What would it mean if a known catalase positive bacteria did not produce bubbles after the addition of H2O2? It would mean that a different strain of bacteria was used that doesn’t react to hydrogen peroxide. 7. If flavoprotein performs the alternate pathway of transferring
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