Essay on Identify An Unknown Gram Positive And Gram Negative Bacteria

1706 Words Oct 19th, 2015 7 Pages
The objective of this lab was to isolate and identify an unknown Gram positive and Gram negative bacteria through the use of various microbiological techniques. The identification of the genus and species for the unknown culture should be obtained based on the characteristics for Gram positive and Gram negative bacteria. Bacteria are prokaryotic microorganisms that lack a nucleus and therefore all its genetic information is stored in the cytoplasm of the cell. The bacterial cell envelope protects the cell and consists of a cell membrane(s) and a cell wall. The cell membrane surrounds the cytoplasm is composed a phospholipid bilayer which contains hydrophobic membrane proteins (Slonczewski & Foster, 2015). The cell wall that protects the cell membrane is composed peptidoglycan and are unique to bacteria (Slonczewski & Foster, 2015). Most bacteria can be divided into two major groups of bacteria, Gram-positive and Gram-negative. These two groups are based on the different physical and chemical properties of the cell wall, which can be determined by a Gram stain (Slonczewski & Foster, 2015). Gram positive bacteria have a two unit cell envelope, a cell membrane and a thick cell wall. The cell wall is composed of several layers of peptidoglycan which are held together by teichoic acids, which gives the cell wall a negative charge. Teichoic acids also consists of lipotechoic acids which have a lipid component that attaches to the cell membrane (Slonczewski & Foster, 2015). Gram…

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