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6 Cards in this Set
- Front
- Back
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What is the chemical composition of teichoic acid? Why is it described as a polymer? Where is this compund usually found? How is it useful in its location?
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Phosphate and sugar alcohols.
It is considered a polymer because it is a macromolecule made of structural repeating units. It is usually found in the cell wall of a gram + cell, within the peptidoglycan. They also assist in regulation of cell growth by limiting the ability of autolysins to break the bond between the NAG and NAM. |
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How does the thickness in Gram + compare to Gram - bacterial cell walls? Describe another major structural difference between gram + and gram - bacterial cell walls.
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The cell wall is thicker in Gram + than Gram -. Another major difference between the two is that Gram - has an outer membrane covering the peptidoglycan.
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What is the chemical composition of lipopolysaccharide (LPS)? Where is this found in abundance? How is this compound useful in its location?
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LPS is made of 3 main components: Lipid A (anchors the rest of the LPS to the outer surface of the outer membrane.), Core Polysacchride (middle) and O-Antigen (outside cell wall) usually found in the Gram - cell wall. The O-Antigen can trigger a response from the immune system when lymphocytes become exposed to them inside the body.
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What bacterial species lacks a cell wall? Which morphoglogical feature of these bacteria is associated with lack of a cell wall? How do these species compensate for lack of a cell wall?
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Mycoplasma and they morph into a thin flexible shape.
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What is a lysozyme? Where is this naturally found? What effect does it have on bacterial cell walls? Why does this effect differ for Gram + and Gram - bacteria?
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A lysozyme is an enzyme found in some body fluids like tears, sweat, saliva. When a glycan chain fits into the action site, a reaction occurs and breaks down the covalent bond between NAG and NAM. Gram + is more suseptible to destruction of the cell wall, where are Gram - have the outer wall that prevents the lysozyme from breaking down the cell wall.
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Describe the effects that penicillian has on susceptible bacterial cells at the molecular level and at the cellular level.
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The penicillian prevents the peptidoglycan from synthesis by interfering with the glycan chains the NAM is supposed to connect with.
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