Bleach was found to be a successful disinfectant against the bacterium S.epidermidis and E.coli, at all concentrations. Bleach is a household chemical substance that acts as a halogen-releasing agent specifically releasing chlorine. As bleach is an oxidizing agent, it facilitates the surge of cellular activity of Hsp33, which are redox-regulated chaperone proteins of the bacterial cell. This chaperone protein prevents the bleach from oxidizing the bacteria, which protects the cell against protein unfolding. Due to it being a stress protein, at especially high concentrations of bleach, these redox reactions lead to an over-activation of the protein, ultimately causing overstress and death. Our observations showed that at the low concentrations
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When DNA absorbs the radiation at 254 nm, the cell utilizes that energy to form new covalent bonds between the pyrimidine dimers, which alter the DNA and impede with proper replication and transcription processes. Baring E.coli at 20 minutes, all species had some form of growth when sheltered from the UV light, which was expected because there are less harmful effects to the cells DNA by doing this. The E.coli had a consistent decreasing trend of growth when exposed to prolong UV radiation. This was expected due to irreversible damage that the DNA sustain during the exposure, leading to the cell to die. The B.subtillus grown for 24 hours had a trend of decreasing abundance of growth during the entire duration when unmasked except for a slight increase in growth at 20 minutes. Although this result at 20 minutes was not expected, the general trend of the experiment was expected. B.subtillus grown for 24 hours is absent of spores that are important in allowing the bacteria to survive in adverse conditions, so it is expected that it would not survive the prolong UV exposure. The outlier in this experiment may have arisen due to a possible contamination that may have occurred when the agar plates were exposed to the air, leading to the loss of purity of the culture. B.subtillus grown for 7 days does have spores that are needed to allow it to survive the UV radiation, so it is expected that there should, at least, be some growth during all times of UV exposure. This was the case for most of the times except the 15-minute mark. The possibility for this outcome, as well as for the absence of growth of masked E.coli at 20 minutes, is that the bacteria amount was so little that growth could not successfully occur. The
When DNA absorbs the radiation at 254 nm, the cell utilizes that energy to form new covalent bonds between the pyrimidine dimers, which alter the DNA and impede with proper replication and transcription processes. Baring E.coli at 20 minutes, all species had some form of growth when sheltered from the UV light, which was expected because there are less harmful effects to the cells DNA by doing this. The E.coli had a consistent decreasing trend of growth when exposed to prolong UV radiation. This was expected due to irreversible damage that the DNA sustain during the exposure, leading to the cell to die. The B.subtillus grown for 24 hours had a trend of decreasing abundance of growth during the entire duration when unmasked except for a slight increase in growth at 20 minutes. Although this result at 20 minutes was not expected, the general trend of the experiment was expected. B.subtillus grown for 24 hours is absent of spores that are important in allowing the bacteria to survive in adverse conditions, so it is expected that it would not survive the prolong UV exposure. The outlier in this experiment may have arisen due to a possible contamination that may have occurred when the agar plates were exposed to the air, leading to the loss of purity of the culture. B.subtillus grown for 7 days does have spores that are needed to allow it to survive the UV radiation, so it is expected that there should, at least, be some growth during all times of UV exposure. This was the case for most of the times except the 15-minute mark. The possibility for this outcome, as well as for the absence of growth of masked E.coli at 20 minutes, is that the bacteria amount was so little that growth could not successfully occur. The