hadiiii_Module One Lesson One Assignment

Google Doc Access Directions: ● Please click on File in the upper left corner. ● If you are working on a Chromebook or Google Docs, choose the Make a copy option and save a copy of the document to your Google Drive. ● If not, choose the Download as option and then the Microsoft Word (.docx) option to download an editable copy of the document to your computer. There are different ways to kill the bacteria that we don’t like. We can use antibiotics (anti: against biotic: life). There are two main types of antibiotics: Bacteriacidal and Bacteriostatic. These two work differently. Bacteriocidal antibiotics will kill bacteria by preventing the formation of the protective cell wall. A couple of examples of these antibiotics would be penicillin, ampicillin, amoxicillin… Bacteriostatic antibiotics prevent the growth of bacteria by, usually, binding to the prokaryotic ribosomes. A couple of examples of these antibiotics include tetracycline and erythromycin. Alcohol can also kill bacteria by breaking down the cell wall and cell membrane. Mouthwash works because of the alcohol found within the products. In these labs, we will prepare a nutrient agar plate that we will use to culture mouth bacteria. Once we place the bacteria in the nutrient agar plate., we will place antibiotic discs (paper discs full of specific antibiotics) and mouthwash discs (paper discs soaking in different mouthwashes). After 24 hours (the petri dishes will be placed in an incubator of 37 o C), we will measure the clear zones from the edge of the paper disc to the closest bacterial colony. The larger the clear zone, the more deadly the antibiotic or mouthwash. Here are the antibiotics that we will be testing: penicillin, ampicillin, tetracycline, and erythromycin. Here are the different mouthwashes that we will be using: Listerine, Scope, Cool Mint Listerine, Kroger Classic Mint, Crest Pro Health, Kroger Mouthwash, and Water. In order to determine how to manipulate your data, you will need to calculate the average, standard deviation and standard error. If you need a refresher of how to calculate standard deviation and standard error, use this link. Purpose: The goal of this experiment is to see how successful different antibiotics and mouthwashes are at killing germs in the mouth. We hope to measure the clean zones generated surrounding each treatment by cultivating oral bacteria on nutrient agar plates and exposing them to various antibiotics and mouthwashes.These distinct zones show the level of bacterial growth inhibition, allowing us to compare the efficacy of various antibiotics and mouthwashes. Hypothesis/Introduction for antibiotics: Antibiotics are substances that can selectively target and inhibit the growth of bacteria. They play a crucial role in treating bacterial infections and preventing their spread. In this experiment, we will explore the effectiveness of different antibiotics in eliminating mouth bacteria. We expect that each antibiotic will have a distinct mechanism of action, leading to varying degrees of bacterial inhibition. Define Antibiotics:

Antibiotic/Mouthwash Lab Name: ___________________________________ Antibiotics are chemical compounds produced by microorganisms or synthetically manufactured that have the ability to kill or inhibit the growth of bacteria. They work by targeting specific components of bacterial cells, disrupting vital processes and rendering the bacteria unable to proliferate. Types of Antibiotics that we will use: We will be using two main types of antibiotics: bactericidal and bacteriostatic. Bactericidal antibiotics act by disrupting crucial processes in bacterial cells, ultimately leading to their death. On the other hand, bacteriostatic antibiotics inhibit bacterial growth and replication, giving the immune system an opportunity to eliminate the bacteria naturally. How do these Antibiotics work? Bactericidal Antibiotics (e.g., Penicillin, Ampicillin): These antibiotics prevent the synthesis of the bacterial cell wall, a vital structural component. Without a functional cell wall, bacteria become susceptible to osmotic stress and eventually burst. This mechanism is particularly effective against rapidly growing bacteria. Bacteriostatic Antibiotics (e.g., Tetracycline, Erythromycin): Bacteriostatic antibiotics interfere with critical processes within bacterial cells. For example, they can bind to prokaryotic ribosomes, disrupting protein synthesis. As a result, bacterial growth is halted, and the immune system can clear the affected bacteria. Which will kill the most mouth bacteria? The effectiveness of each antibiotic in killing mouth bacteria can be inferred from the size of the clear zones formed around the antibiotic discs. Larger clear zones indicate stronger bacterial inhibition. Therefore, the antibiotic with the largest clear zone will likely be the most effective at killing mouth bacteria. By comparing the results obtained from testing different antibiotics and mouthwashes, we can gain insights into their relative effectiveness in combating mouth bacteria. This information may have implications for selecting appropriate antibiotics and mouthwashes for oral hygiene and medical use. Hypothesis for Mouthwash: Mouthwashes work by incorporating active ingredients that can target and eliminate harmful bacteria present in the mouth. These active ingredients might include antimicrobial agents, such as alcohol, essential oils, or chlorhexidine. The mouthwash's effectiveness in killing bacteria 2

Antibiotic/Mouthwash Lab Name: ___________________________________ 6 11 14 5 1 7 4 6 9 7 Average 7.86 7.29 3.86 5.86 Std. Deviation 6.09 7.21 3.07 4.33 Std. Error 2.17 2.57 1.09 1.53 Create a graph with the standard error bars Table 3: Mouthwash: Clear Zones in mm Groups Listerine Scope Cool Mint Listerine Kroger Classic Mint Crest Pro Health Kroger Mouthwas h Water 1 4 7 3 5 7 6 3 2 1 5 2 2 4 7 0 3 N/A 5 N/A 6 4 4 4

Antibiotic/Mouthwash Lab Name: ___________________________________ 4 2 3 5 5 8 5 0 5 N/A 10 N/A 20 9 N/A 0 6 0 5 0 0 5 6 0 7 1 3 4 2.5 5.5 2.5 3 8 0 2 0 5 2 2 0 Average 3.29 3.29 2.29 3.00 4.14 3.71 2.14 Std Deviation 2.21 2.21 1.93 2.12 2.27 2.76 1.86 Std Error 0.82 0.82 0.72 0.79 0.84 1.03 0.69 Create a graph with the standard error bars Conclusion: (6 points: 2 points each) 1) What does the standard deviation show you? The standard deviation measures the degree of variance or dispersion among data points. A bigger standard deviation implies that the values are more variable, whereas a lower one shows that the values are closely clustered around the mean. 5