My Citrate (CIT) result was turquoise so that meant the test was positive, and the Hydrogen Sulfide (H2S) had no black precipitate so it was negative. The Urea (URE) and Tryptophane Deaminase (TDA) results were both an orange color, which meant they were both negative. For Indole (IND), my result was yellow so it was negative. My result was colorless for the Voges Proskauer (VP) test so it was negative. The Gelatin (GEL) test result had no diffusion of pigment so that showed it was negative.
As well as being able to successfully grow and reproduce, the E. coli in the LB/amp/ara +pGLO plate also emitted a fluorescent glow when exposed to UV light. This can be explained by the examining the medium in which they were grown in. The bacteria were transformed with the pGLO plasmid which contained the GFP and resulted in glowing bacteria, however, in order for this to occur the arabinose C sugar must be present in the medium. This sugar is responsible for the activation of the GFP6. Recall that in the E. coli cells in LB/amp +pGLO plate were also transformed but did not express the fluorescent glow.
Recovery broth was added to the cell suspension, and the bacteria was placed in warm water for about thirty minutes (see Results and Discussion, paragraph 2). This recovery period let the bacteria repair their cell membranes and express the added genes. Lastly, the transformed E. coli were placed on agar plates and allowed to grow overnight. One agar plate only contained nutrients (-DNA), two contained nutrients and ampicillin, (-DNA/Amp and +DNA/Amp), and one contained nutrients, ampicillin, and IPTG, a protein that caused the GFP to express a glow. After completing the lab, it was discovered that the ARG gene creates a resistance to antibiotics, like ampicillin, and that bacteria can take in new genes.
The objective of the sludge lab was to determine how many different pure substances were in the sludge by using the methods and techniques we have learned throughout the year. We had to pick separation methods so we could separate our sludge and then test characteristic properties on our separated liquids and solids. This experiment made us use our knowledge on characteristic properties to pick the ones we should test to help us identify our pure substances. Characteristic properties are properties that help identify a solid or liquid. Each solid or liquid has a certain density, boiling point, solubility, flammability, so if you know what each one is then you can use that information to help you identify your solid or liquid.
Based on the results the hypothesis is correct that if tobacco extract is added to food vacuoles that less vacuoles will be visible and cellular process would slow down. The contamination of samples and the use of tetrahymena in which most of the cells in the samples were dead made it difficult to get a ratio of cells to vacuoles that accurately depicted the difference between cells with nicotine and cells without. Factors that affected the accuracy of the experiment was unfamiliarity with the equipment and difficulty of find the cells on the slides. One questions posed is at what concentration of nicotine would other cell functions begin to shut down. From this experiment, we can see that the assumption we made about human appetite suppression could be
Xylene should be dried because it will be removed from the product. A drying tube with calcium chloride was used for the reaction during the set up because it will remove and catch specific compounds leaving the reaction or being produced from the reaction. The purification method is by using adding petroleum ether to produce crystals and then vacuum filtration to remove the crystals from the solution. The melting point for 4-cyclohexene-cis-1,2-dicarboxylic anhydride as a pure compound is measured at approximately 97-103ºC. The measured melting point from the experiment is approximately 70-80ºC.
If this test is positive, the hydrogen peroxide which is dropped onto the colonies in the streak plate will begin to bubble. If bubbles are produced that means the organism is an aerobe. Because H2O2 is such a potent agent, if an organism lives in the presence of O2, they need to be able to break down the H2O2 to survive. The bacteria tested positive for catalase, as the hydrogen peroxide was dropped onto the streak plate, it immediately began to produce bubbles.
After receiving an unknown mixture, the sample was streaked for isolation onto TSA, blood agar, and MacConkey plates. Each plate serves as a first step to identify the unknowns. The TSA (tryptic soy agar) can be used to do a gram stain, which differentiates gram-negatives from gram-positives, based on the structural make up of the cell wall (Carson, 2015). The blood agar plate is used to test for hemolytic activity, which is useful for distinguishing gram-positives. A MacConkey plate is selective by inhibiting the growth of gram-positives and differential due to the fermentation of lactose by certain gram-negative species.
Copper Sulphate can block the activity of Amylase, which is a known non-competitive irreversible enzyme inhibitor. The light absorbent method can be used to study this phenomenon of breakdown and blockade of breakdown of starch in the laboratory. After studying these properties of Amylase and Copper sulphate I designed my experiment to study the inhibitory effect of Copper Sulphate on the enzymatic activity of 1% and 2% Amylase solution. Starch was used as a substrate and a calorimeter to detect the light absorbance to confirm enzymatic breakdown and its blockage by copper
You must first test the pH level of the amylase and starch solution using pH test strips, so that the experiment may be fair m. Then measure 3cm3 of amylase solution using the measuring cylinder, the pour it into the test tubes labeled A1-A5 n. Do the same for the starch solution but pour into the test tubes labeled S1-S5 o. Put test tubes A1 and S1 into the beaker labeled “cold water” p. Put test tubes A2 and S2 into the beaker labeled “normal water” q. Put test tubes A3 and S3 into the beaker labeled “warm water” r. Put test tubes A4 and S4 into the beaker labeled “very warm water” s. Put test tubes A5 and S5 into the beaker labeled “hot water” t. Mix the amylase solution with the starch solution when both are at the same temperature in each beakers (pour the amylase solution into the starch solution) u. Quickly add 3 drops of iodine solution into all 5 mixed amylase and starch solutions, while starting the stopwatch for each (should be 5 separate
We got negative for indole (no production of indole, pyruvic acid and ammonia), negative for Methyl Red (our bacteria does not perform mixed-acid fermentation when supplied glucose), negative for Voges-Proskauer (no fermentation of glucose in order to produce 2,3-Butanediol-Butanediol fermentation), but positive for Citrate utilization, which means our bacteria uses citrate as a sole carbon source and energy. Something interesting here is that according to the lab textbook organism that degrade citrate must also use ammonium salts, and in the process, they produce ammonia that causes the medium to become alkaline (under this condition the medium turns to deep Prussian blue, indicating the utilization of citrate). The genus Alcaligenes is well known for being alkali-producing