Therefore, the aim of this experiment is to understand the use of different ingredients for preventing bacterial growth and to find which cleaner is most value for money in regarding prevention of bacterial growth.
It is hypothesised that if the price of the cleaner varies but the ingredients are similar then similar results will still be observed.
To confirm this hypothesis the results will have to show similar results to each other independent of the cost compare to the petri dish with no cleaner.
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Figure 1. Explanation of the figure. Experimental Procedures
The independent variable in an experiment is the variable that is changed to test its effect on the dependent variable. In this experiment the independent variable was the cleaner used. Four cleaners were chosen each of different brands with different ingredients and prices.
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This means when the independent variable is changed the dependent variable is what is effected. In this experiment the dependent variable was the amount of bacterial growth to tell how much effect each of the cleaners had on preventing it. The bacteria growth will be measured by using a computer program that will show the area of prevented bacterial growth on the petri dishes. Each result will be compared to the petri dish with no cleaner. Therefor the effectiveness of each cleaner will be determined to then find the cost effectiveness.
The constant variables:
Bacteria- The type of bacteria and the amount of bacteria had to be kept the same. This was done so that the results showed the effectiveness of the ingredients in the cleaners and not the amount of bacteria on the Petri dishes or the type of bacteria.
Growth conditions- The conditions of where the Petri dishes were placed for growth had to be kept the same because bacteria grows at different rates in varied conditions.
Materials
Five pre prepared Petri dishes with nutrient
What do bacteria need to grow? For bacteria to grow the most typical thing that they like ate a warm and moist environment, but that is not all that they like. Bacteria also like and environment with a PH that is normal or close to a human PH and bacteria also like an oxygen rich environment. The places that could be common to find bacteria in a building are a keyboard, a water fountain, and restrooms. A keyboard is a common place for bacteria because it is being touched constantly with hands when people type and hands are warm, so bacteria like them. The water fountain is another place that is common for bacteria to grow because people's warm hands are touching it and also it has water, which causes it to be moist. The last place that bacteria will we commonly found in buildings are restrooms. The bacteria like restrooms because many people are in then and also there is a lot of water in them.
The first day an unknown sample was assigned to each group of students. The first test applied was a gram stain to test for gram positive or gram-negative bacteria. The morphology of the two types of bacteria was viewed under the microscope and recorded. Then the sample was put on agar plates using the quadrant streak method for isolation. There were three agar plates; one was incubated at room temperature, the second at 30 degrees Celsius, and the third at 37 degrees Celsius. By placing each plate at a different temperature optimal growth temperature can be predicted for both species of bacteria.
In this lab project, the microbiology students were given 2 unknown bacteria in a mixed broth each broth being numbered. The goal of this project is to determine the species of bacteria in the broth. They had to separate and isolate the bacteria from the mixed broth and ran numerous tests to identify the unknown bacteria. The significance of identifying an unknown bacteria is in a clinical setting. Determining the exact bacteria in order to prescribe the right treatment for the patient. This project is significant for a microbiology students because it gives necessary skills to them for future careers relating to clinical and research work.
The purpose of this laboratory is to learn about cultural, morphological, and biochemical characteristics that are used in identifying bacterial isolates. Besides identifying the unknown culture, students also gain an understanding of the process of identification and the techniques and theory behind the process. Experiments such as gram stain, negative stain, endospore and other important tests in identifying unknown bacteria are performed. Various chemical tests were done and the results were carefully determined to identify the unknown bacteria. First session of lab started of by the selection of an unknown bacterium then inoculations of 2 tryptic soy gar (TSA) slants, 1 nutrient broth (TSB), 1 nutrient gelatin deep, 1 motility
As I was anticipating writing this paper on American culture, I kept thinking of the culture that biologists grow in a petri dish. More specifically, the bacteria strep, which must be grown in a special medium called, blood agar. If someone has a "positive" culture, the bacteria strep has metabolized the blood in the agar and the petri dish will be clear. If someone has a "negative" culture, the petri dish will remain red.
This experiment was done in 4 replicates. The independent variable in this experiment is the number of candles and the dependent variable is the height of the water that is measured in centimeters. Some of the control variables are keeping the candles the same size also, the same type/brand. further, the same amount of time to let the water to rise. Lastly,
Paper Towels Variables: To enable fair test certain aspects of the experiment will have to be
In our Biology Lab we did a laboratory experiment on fermentation, alcohol fermentation to be exact. Alcohol fermentation is a type of fermentation that produces the alcohol ethanol and CO2. In the experiment we estimated the rate of alcohol fermentation by measuring the rate of CO2 production. Both glycolysis and fermentation consist of a series of chemical reactions, each of which is catalyzed by a specific enzyme. Two of the tables substituted some of the solution glucose for two different types of solutions. They are as followed, Table #5 substituted glucose for sucrose and Table #6 substituted the glucose for pH4. The equation for alcohol fermentation consists of 6 Carbons 12 Hydrogens 6 Oxygen to produce 2 pyruvates plus 2 ATP then finally the final reaction will be 2 CO2 plus Ethanol. In the class our controlled numbers were at Table #1; their table had 15 mL Glucose, 10 mL RO water, and 10 mL of yeast which then they placed in an incubator at 37 degrees Celsius. We each then measured our own table’s fermentation flasks every 15 mins for an hour to compare to Table #1’s controlled numbers. At
Variables Independent Variable (IV) Air Temperature (0°C; 20°C; 37°C; 45°C) The independent variable is the air temperature where the experiment would be held in different temperature ranging accordingly from 0°C, 20°C, 37°C, and to 50°C. The experiments would be carries out at different location with the corresponding temperature listed above. Dependent Variable (DV)
The “Fast Plant” experiment is an observation of a plants growth over the span of twenty-eight days. The objective is to observe how plants grow and use their resources throughout the span of their life. In our lab we observed the Brassica rapa, a herbaceous plant in the mustard family which has a short cycle which makes it a perfect plant to observe in this experiment. Like other plants the Brassica rapa must use the resources in the environment to create energy to complete itʻs life cycle and reproduce. By observing the plant it is easy to see in what organ or function the plant is using itʻs energy and resources and if overtime the resources switch to other part of the plants. By conducting this experiment we are able to observe where and how plants allocate their resources throughout their life by harvesting plants at different points in their life.
Dependent Variables Amount of vitamin C in fruit juices. Controlled Variable Same amount of liquid for each fruit juice.... ... middle of paper ... ...
factors held constant – the door knob that was swabbed, time amount, petri dish, lighting, temperature
Independent variables: The temperature of hcl gas will be decreased and increased throughout the experiment.
Independent variable (pg. 39) – a type of variable that is controlled by the experimenter, and comes before the dependent variable. An example of an independent variable in a study would be the amount of time played by a college football player.
In addition, since bacterial growth is affected by many other factors such as pH of the medium and age of the bacteria, these factors must be kept constant throughout the experiment to ensure the accuracy of the results.