Biochemical Test Essay

Many scientist today cut portions of DNA with restriction enzymes and include a piece of new genetic material into the bacterial cells. The only way this transformation can take place is if the bacteria is competent and is grown to the right stage in which they are dividing the most. In order for this to happen,one would treat the bacterial cells with Calcium Chloride (CaCl2). The bacteria used in this lab was E.Coli and it was an ideal bacteria because it can be easily grown on agar. Hypothesis The transformed E.Coli with the ampicillin resistance gene will be able to grow in the ampicillin plates and it would have a green glowing color.

Recovery broth was added to the cell suspension, and the bacteria was placed in warm water for about thirty minutes (see Results and Discussion, paragraph 2). This recovery period let the bacteria repair their cell membranes and express the added genes. Lastly, the transformed E. coli were placed on agar plates and allowed to grow overnight. One agar plate only contained nutrients (-DNA), two contained nutrients and ampicillin, (-DNA/Amp and +DNA/Amp), and one contained nutrients, ampicillin, and IPTG, a protein that caused the GFP to express a glow. After completing the lab, it was discovered that the ARG gene creates a resistance to antibiotics, like ampicillin, and that bacteria can take in new genes.

Introduction Our world is composed of many bacteria’s’ that can either help or destroy us. Therefore, its’s imperative to learn and study them. The purpose of the lab was to put into action the methods that have been learned in the laboratory to determine our unknown bacteria. Bacteria’s can have different features, shapes, and or arrangements that help microbiologist determined their role in our life (whether they are good or bad for humans). Bacteria can be classified as gram positive or negative (difference in call wall).

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.

The six bacteria used in this lab were, Citrobacter freundii, Bacillus subtillis, Enterobacter aerogenes, Staphylococcus epidermis, Enterococcus durans, and Escherichia coli. Citrobacter freundii is a Gram-negative rod shape bacteria. The MSA plate will grow Citrobacter freundii, Bacillus subtillis, Enterobacter aerogenes and will have a yellow color change while Staphylococcus epidermis will not grow nor have a color change to yellow. The MacConkey agar will have growth with Escherichia coli, Enterococcus durans, but not Staphylococcus epidermis and Bacillus subtilis since it is a Gram-positive. Only Escherichia coli and Enterococcus durans will be the species fermenting.

Our results from the PCR process were very unexpected, even to the point the control colony had some rather odd outcomes. The goal of this experiment was to choose three colonies from the petri dish that has been exposed to +Amp, and look for any signs of the +Amp resistant gene, blaTEM, within the colonies and decide if this gene does have an impact on bacterial resistance towards the antibiotic. My partner and I decided to utilize a bacterial colony sample that does have blaTEM genes as our control group for us to indicate what a blaTEM gel strand would appear in the agarose gel results. When observing the product of the gel product after gel electrophoresis, we were surprised to find out none of our three colonies had any strands that indicated the presence of blaTEM despite each of them surviving through the exposure to this antibiotic.

However, when these bacteria are grouped together to have high cell density, the molecules they secrete amount to a certain number, and once that number is reached, the behavior of that bacteria is switched on and in this case, bioluminescence is created. Similarly, in my project, I am screening the anti bacterial activity using oils. Before I use the oil, I have to culture the bacteria overnight so that I could use them in the plates after 16-18 hours of incubation. Based on the talk, I believe that I have an idea on how bacteria grow. This Ted Talk has inspired me about science in numerous aspects.

Using the lit tea light, like a bursen burner, I flamed the mouth of the S. epidermidis culture. The sterile cotton swab was inserted in the S. epidermidis culture and twirled around to obtain a specimen. The entire plate was inoculate with the swab from top to bottom, to achieve a lawn of growth. The dry forceps was used to remove the antibiotic disk into the appropriate spot on the plate. This process was repeated for the all antibiotics with aseptic technique being used.

Investigable Question My investigable question for the LJOC experiment was how does the pH level of the water in the jars affect the population size of protozoans? pH level, is a scale that measures the concentration of hydrogen ions. On the pH scale, somewhat surprisingly, 7 is neutral—not 0, and anything higher than 7 is basic, and anything lower than 7 is acidic. Background When we (Maleek and I) setup the experiment, which involved 3 jars, we weighed some grass and put some of the grass into each of the jars. We then began to experiment combining water with vinegar (which we knew had an acidic pH around 3), and later with baking powder (which we knew had a basic pH around 9), to find the mixtures for a pH of 5 and of 9.

Lastly is the evolution of MRSA (Methicillin-resistant Staphylococcus aureus). MRSA is a bacterium that is responsible for various infections in humans that are difficult to treat due to its development of a resistance to common antibiotics. MRSA is very common in hospitals, prisons, and nursing homes. Biological Diversity