Bacterial cell structure

Introduction The Gram stain is a valuable tool to microbiologists in identifying the cell well composition of prokaryotic species. The underlying process revolves around a series of chemical dyes, and their propensity to bind to peptidoglycan polymers in the cell wall. The results allow scientists to infer properties about the outer coating of an organism and is often the first step in identifying an unknown species. For the purpose of our experiment, the results of the Gram stain will be as follows: Gram positive (G+), where the first dye was able to bind within the cell and hold throughout the process, or Gram negative (G-), where the first dye is not able to bind and the second dye is observed. Some known Gram-positive genera are Bacillus,…

students were assigned to collect and identify an environmental sample down to the genus level. For this particular experiment a skin bacterial sample, taken from the arm, was selected and put through different differential…

In addition, procedure part H contains the viewing of cheek cells, cheek cells are a high-caliber option for identifying the membrane, and cytoplasm of a cell. To begin, place a drop of methylene blue on a slide, then smear a toothpick amongst the inside of the cheek, lastly smear the toothpick onto the stained slide. Cheek cells just like starch cells are hard to be viewed without the addition of a staining chemical, in this case, the methylene blue will make the cheek cells have a slight blue…

It is a selective media because, it kills Gram positives but allows Gram negatives to survive. If there is growth present on the EMB media it means it is a Gram negative rod. The color of the results determine if lactose fermentation is present. If the sample is colorless then there is no lactose fermentation present. If the bacteria is purple then lactose fermentation is present. If the results have purple and green colors then the sample has great amounts of lactose fermentation. The lab…

gram-positive bacteria, the cells were arranged in a cocci cluster, while in the gram-negative bacteria, the cells were arranged in a rod cluster. Both the gram negative and gram-positive bacteria exhibit a small yellow colony on the TSA plate. After 48 hours, the MSA plate was observed. Individual isolated colonies were found throughout the plate, with a yellowish color. The medium also changed from a reddish color to a yellowish color, indicating that the unknown gram-positive bacteria was…

After part 1, the experimenters found two things about the Bacteria: First, that the bacterium was bacilli (rod) shaped. This was determined by viewing individual cells through a microscope at 400x power. Secondly, that the bacterium was most likely a Gram-stain-negative because it appeared to be a pink color after gram-staining. This had several implications: The experimenters now knew the bacteria’s cell wall composition, its outer membrane composition, peptidoglycan concentration, outer…

bacteria for examination under a microscope. Also learned in this lab were methods on how to inoculate an agar or broth medium, and using aseptic techniques. Lastly, how to use stains to visualize bacterial cells, or distinguish different types of cells from one another through the usage of dye techniques such as the Gram-stain test was learned. II. Prepping/Mounting/Simple Staining Bacterial Cells Procedure: 1. Obtain 3 glass slides that are free of any foreign matter. 2. Place one drop of…

circumstance the bacteria could be resistant to that particular drug. (5 pts) As the name implies 50s subunit protein synthesis inhibitors such as erythromycin inhibit protein synthesis by binding to the 50S subunit of the 23S rRNA molecule of the bacterial ribosome. This ultimately acts to block the exit of the growing peptide chain. It should be noted that gram+ bacteria more effectively accumulate erythromycin than gram negative bacteria thereby making it more effective in this group of…

In conclusion, the hypothesis the SPC method of establishing a growth curve and determining the number of bacteria colonies present in a culture would be more accurate than the OD spectrophotometer could be true in more experienced cases where there is less chance of human error because the Spec 20 cannot differentiate viable cells and dead cells. The Standard plate count method, considering if the inoculations and dilutions are done correctly, and the environmental conditions are most efficient…

Illustration of sexduction in E. coli using streptomycin resistant F-lac- recipients and F′lac+ donors Abstract The process in which DNA from a donor cell is transferred through physical contact into a recipient cell is known as conjugation. In the experiment, sexduction, a cross between F′ and F- plasmids, was demonstrated by mixing the donor and recipient, diluting them and using selective plating methods. The plasmids from the donor, recipient and transconjugant were isolated and analyzed…