Cell Wall Of Prokaryotes And Its Function

9 Questions | Total Attempts: 79

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Cell Quizzes & Trivia

The quiz examines your understanding of the prokaryotic cell wall and its function. The ability to understand will allow you to apply this knowledge in genetic engineering lab where you will need to isolate DNA from either gram positive or gram negative bacteria.


Questions and Answers
  • 1. 
    The difference between a gram positive and a gram negative is listed. below. Which is not true of the following?
    • A. 

      The gram-negative cell wall is a multilayered structure and quite complex

    • B. 

      The gram-positive cell wall consists of primarily a single type of molecule and is often much thicker

    • C. 

      Neither has peptidoglycan

    • D. 

      Both have peptidoglycan

  • 2. 
    The following describe components of peptidoglycan of gram negative bacteria except for:
    • A. 

      Peptidoglycan of gram negative consists of two types of sugars N-acetyl muramic acid and N- acetyl glucosamine

    • B. 

      N-acetyl muramic acid is unique to gram negative bacteria

    • C. 

      The peptide part of peptidoglycan consists of a small group of amino acids consisting of L-alanine, D-alanine, D-glutamic acid, and either lysine or diaminopimelic acid (DAP)

    • D. 

      The peptidoglycan of gram negatives is thin as compared to gram positive

  • 3. 
    In Staphylococus aureus, the interbridge consists of _____________________ linked by a____________ bond.
  • 4. 
    THe difference between gram positive and gram negative peptidoglycan is:
    • A. 

      In gram-positive bacteria, as much as 90% of the cell wall consists of peptidoglycan, although another kind of constituent, teichoic acid is usually present in small amounts

    • B. 

      In gram-negaitive Bacteria, as much as 90% of the cell wall consists of peptidoglycan, although another kind of constituent, teichoic acid is usually present in small amounts

    • C. 

      Gram-negative Bacteria, have several (up to about 25) peptidoglycan layers. while gram positive has a single but thin layer

    • D. 

      In gram-negative bacteria about 90% of the wall is peptidoglycan, the majority of the wall consisting of a complex layer

  • 5. 
    Because techoic acids are negatively charged, they are partially responsible for the negative charge of the cell surface of a gram-positive bacteria. They also function to effect the passage of ions through cell wall. Is this true of techoic acid?
    • A. 

      True

    • B. 

      False

  • 6. 
    Which statement is not true of LPS?
    • A. 

      Gram-negative Bacteria contain an additional wall layer made of lipopolysaccharide.

    • B. 

      This layer is effectively a second lipid bilayer, but it is not constructed solely of phospholipid, as is the cytoplasmic membrane; instead it contains polysaccharide and protein.

    • C. 

      Polysaccharide consists of two portions, the core polysaccharide and the O-polysaccharide

    • D. 

      Lipid A which linkes the core-polysaccharide prtion is antigenic

    • E. 

      None of the above is true

  • 7. 
    Connected to the core is O-polysaccharide whch is composed of 6 carbon sugars listed below except for:
    • A. 

      Galactose

    • B. 

      Sucrose

    • C. 

      Glucose

    • D. 

      Mannose

    • E. 

      Rhamnose

  • 8. 
    Fatty acids are commonly found in Lipid A: Which one is not found in Lipid A
    • A. 

      Caproic

    • B. 

      Lauric

    • C. 

      Myristic

    • D. 

      Palmitic

    • E. 

      Oleic

  • 9. 
    The following are principles of gram-staining. Which of them is not one of them?
    • A. 

      Following decolourization procedure, an insoluble crystal violet-iodine complex is formed inside the cell, and this complex is extracted by alcohol from gram-negative

    • B. 

      Gram positive bacteria have thick peptidoglycan, so insoluble complex is not able to evaporate through the pores which closes upon dehydration by alcohol

    • C. 

      Gram positive bacteria retain the blue colour of crystal violet due to the presence of thick peptidoglycan

    • D. 

      Gram positive bacteria retain the pink colour of safranin due to the presence of thick peptidoglycan