We repeated this experiment using another five set of cups that contained 50 mL of 1M sodium chloride. After gathering the data, we calculated the change in weight of the yam cores, performed a t test and constructed graphs. After performing a t test, I found the p value
• Iodine Solution Weigh 7.7g of potassium iodide into a 50cm3 beaker. Use distilled water to help the iodide dissolve. Swirl for a few minutes until the iodide has completely dissolved. Using a funnel to help, pour the potassium iodide into a 500cm3 volumetric flask, make sure all traces of the solution is in the volumetric flask. Using distilled water would be a good method in order to rinse the beaker.
The results in this were expected. In this lab, human error could have possibly been that the salt wasn’t fully dissolved or even the Kool-Aid wasn’t fully dissolved. To fix this next time, both mixtures can be stirred a little longer. A third human error could have been when putting 20 drops into the test tubes, some drops were bigger than others causing there to be more than mL of mixture in the test tube. At the end of the lab, a red and yellow M&M were used to do a home material test.
Extra care was taken to not touch the plate with bare skin. Five spots were labeled on the line and each amino acid standard was spotted on the plate using a capillary tube. The standards included leucine, alanine, phenylalanine, and lysine. The final spot was an unknown mixture of three amino acids. After allowing the spots to dry, the plate was placed in the developing jar and allowed to develop.
1 “substrate” and another “ enzyme.” Instead of using the distilled water, this time you are going to use different pH buffer in the enzyme test tube. In the substrate tube, add 7 mL of distilled water, 0.3 mL of hydrogen peroxide, and 0.2 mL of guaiacol for a total volume of 7.5 mL. For the enzyme tube, instead of distilled water add the pH solution (3) and 1.5 mL of peroxidase which equals a total volume of 7.5 mL. Use the dH2O syringe for our pH solution. To clean the syringe, flush it by drawing 6 mL of distilled water.
The SIM tube was first inspected for black precipitate indicating sulfur reduction and cloudiness around stab line for motility. Kovacs reagent was added in the tube a red color change in the alcohol layer. Red which also indicated is was positive for indole production. Methyl Red is used to determine if an organism is capable of performing a mixed acid fermentation. Methyl Red were added to MR test tube.
Before starting the heating process, measure the weight of the crucible with its cover first and then tare the balance, and after that adding about 1 gram of the sample to the crucible with its cover, and then weigh it. Moreover, it is possible liberating harmful gases during the process of heating; therefore, being careful is important. The heating process ends when this sample changes the color to brown because water of hydration is removed to the sample. Additionally, give time to the small cool down and measure its weight. Next, transfer the sample to a 50 mL beaker and mixes with distilled water, which gets by rinsing the crucible with its cover in 8mL, so the solution is generated.
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 A milk-based, litmus broth tube is incubated and observed after 48 hours.
Using two test tubes, label one “s” for substrate and the other “e” for enzyme. The substrate tube should contain 7 mL of distilled water, 0.3 mL of hydrogen peroxide, and 0.2 mL guaiacol and the enzyme tube should contain 6 mL of distilled water and 1.5 mL of peroxidase. Combine the materials of the substrate and enzyme tubes, mix the two using a clean transfer pipette, transfer a portion into a cuvette so that the cuvette is about half-full then cover the top of the cuvette with Parafilm and then place it in the spectrophotometer and record absorbance. Remove the cuvette and repeat recording absorbance at 1, 2, 3, and 4 minutes. Be sure to mix the cuvette and clean its surface with Kimwipes before each reading.
After testing the burret reading, the next step was to start the experiment by preparing approximately 0.1 M NaOH solution. First calculate the amount of 6.0 M NaOH stock solution needed to prepare 500 mL of 0.1 M NaOH solution. A 10.00-mL graduated cylinder was used to measure the the calculated amount of 6.0 M NaOH, and then filled to the top with deionized water. The 10.00 mL was then poured into a 500 mL plastic bottle. The 10.00 mL graduated cylinder was refilled with deionized water and was poured into the same 500 mL plastic bottle.