The Antimicrobial Properties of Plants

The following tests according to the lab manual were performed: gram stain, fermentation tubes, methyl red, vogues proskauer, sulfur, indole, motility and growing it up on MacConkey agar. The gram stain was performed incorrectly the first time. This is because the decolorizer was not on the bacterium slide for long enough, giving a false outcome.

The purpose of the control group is the keep the experiment consistent throughout for the best results. For instance, four white carnations are placed in four vases with plain tap water. Two of them have other liquids added to them, making the plain tap water flowers the control group. They stay consistent

8. If the biochemical test requires an incubation of 24 hours, what do you need to do? (1 pt)

An experimental control is a test that lacks the experimental variable. Was one of the solutions prepared in this lab a control? If so, which one? Yes, the tap water being boiled at a 100.5 C that receives no added table salt is the experimental control.

The problem that needed to be solved for this experiment was, “How are organisms able to survive and function with proficiency despite metabolic activities that have the disastrous ability to alter pH from a neutral to an acidic or basic environment?” This question needed to be answered by testing different biological materials, as well as tap water, in order to find out what allows modern day organisms to survive such hazardous conditions. A hypothesis that was formulated before experimenting was, “If type of substance is Tap Water, then the changes in pH will be more drastic because water, considered neutral on the pH scale, doesn’t contain a component that will prevent such a change, unlike the content of a buffer solution.” The independent variable for this experiment was type of substance, evidently because this was the part of the experiment that was constantly being changed from trial to trial. The dependent variable for this experiment was pH of the substance because the pH constantly changed depending on the type of substance was being experimented with. The control of this experiment was the tap water and buffer solutions, as the results of the data from the biological materials were constantly compared to the data from both of these solutions.

My partner and I choose glucose, colchicine, cold temperature (0 degrees Celsius), and warm temperature (37 degrees Celsius) as the addition factors. The tetrahymena were exposed exposed to their condition for ten minutes before the India ink was placed in their microcentrifuge. The tertrahymena were fixed on a slide every ten minutes after the ink was placed in the microcentrifuge. In this experiment there are two controls. There is positive control and a negative control. The untreated sample is tetrahymena that did not have any other conditions besides the ink. Then before the sample was placed on the slide they were fixed. The treated sample was tetrahymen mixed with

The control used in the experiment was water. For each trial we set up, it was to see the results between our assigned extract and water. This was useful in interpreting our results because our results were based on how the insects responded. If they had no preference to either strip, attraction to the plant extract, or if they

Today with my group lab we had to discuss on how to design an experiment that investigated the two herbicides DCMU and DCPIP. We used Elodea leaf and Elodea is basically a genus of aquatic plants often called the waterweeds and can be found anywhere in a pond or under water. So we started by creating a solution of phenol red, by adding 5 drops of concentrated phenol red to 40mL of water, then one of our group member used a straw to gently blow air into the solution until it reaches a neutral pH. We then transferred the solution into two test tubes evenly and labeled each tube dark and light, meaning the dark one will stay in the dark and the light one will stay under light bulbs. We predicted that dark one will stay the same and the light

variable one is testing for. In this experiment the importance of the control was to compare the

The test tube was labeled with the bacteria identifying number. The cap on test tube was removed, and the lip of the test tube was flamed. Next, the Bunsen burner was used to sterilize the inoculating loop. Then, bacteria were picked up from the working plate with the loop and the agar was inoculated. The loop was then re-flamed. Finally, the plate was placed in the 37˚C incubator and left to sit for 48 hours and any changes in color were observed. A negative result appears green, and a positive result appears blue. This is because it tests for the organism’s ability to use citrate as its sole source of carbon, and if it does then it produces ammonia and ammonium hydroxide which make the medium basic, changing the green agar blue (Leboffe & Pierce,

Oxidase Test: Using a sterilized loop inoculate a loopful of bacteria into the test square and

After gaining some knowledge about bacteria, we were giving an investigating bacteria growth lab to do. Our objective was to observe the conditions required for bacteria to grow and to test the effectiveness of substances that may be antibacterial, disinfecting, and or sanitizing. My group and I began our procedure by gathering all the bacteria by swabbing our necks and mouths. After this, we inoculated the culture by rubbing the bacteria on the agar, a nutrient rich gel made from sea kelp, on the bottom side of the container where we grow bacteria, the Petridish. We hoped for the results to come back with little or even no colonies and an immense zone of inhibition around the tiny circle cut out of filter paper covered in toothpaste, Neosporin, and Chlorhexidine Gluconate 4% Solution.

to compare the results, and neither solution was expected to produce an observable chemical reaction. The procedure was the same as used for the test with 6M HNO3 and 0.1M AgNO3 solution and the test with 6M HCl and 0.1M BaCl2 solution. A third experiment used was the flame test. First, a scoopula was used to place 0.1 grams of the unknown compound in a test tube, and a wash bottle was used to add approximately 2 mL of deionized water to create a solution.

To answer this question, a multiple day experiment was conducted to determine whether there is merit to the use of certain natural treatments to treat a bacterial infection by comparing to antibiotics that are known to be effective.

experiments. The biosafety level 2 lab required stringent procedures such as ethanol being sprayed on everything that entered the hood. I was