Skip to main content
Biology LibreTexts

4.E: Using Antibiotics and Chemical Agents to Control Bacteria (Exercises)

 

These are homework exercises to accompany Kaiser's "Microbiology" TextMap. Microbiology is the study of microorganisms, which are defined as any microscopic organism that comprises either a single cell (unicellular), cell clusters or no cell at all (acellular). This includes eukaryotes, such as fungi and protists, and prokaryotes. Viruses and prions, though not strictly classed as living organisms, are also studied.

4.1: An Overview to Control of Microorganisms

Study the material in this section and then write out the answers to these questions. Do not just click on the answers and write them out. This will not test your understanding of this tutorial.

  1. Matching:

    _____ An agent that kills the organism. (ans)

    _____ An agent that inhibits the organism's growth long enough for body defenses to remove it. (ans)

    _____The chemical agent being used should inhibit or kill the intended pathogen without seriously harming the host. (ans)

    _____ A chemical agent that generally works against just gram-positives, gram-negatives, or only a few bacteria. (ans)

    _____ A chemical agent that is generally effective against a variety of gram-positive and gram-negative bacteria. (ans)

    _____ Antimicrobial drugs synthesized by chemical procedures in the laboratory. (ans)

    _____ Metabolic products of one microorganism that inhibit or kill other microorganisms. (ans)

    _____ The process of destroying all living organisms and viruses. (ans)

    _____ The elimination of microorganisms, but not necessarily endospores, from inanimate objects or surfaces. (ans)

    _____ An agent that kills or inhibits growth of microbes but is safe to use on human tissue. (ans)

    1. selective toxicity
    2. broad spectrum agent
    3. narrow spectrum agent
    4. cidal
    5. static
    6. sterilization
    7. antibiotic
    8. chemotherapeutic synthetic drug
    9. antiseptic
    10. disinfection
    11. disinfectant

4.2: Ways in which Chemical Control Agents Affect Bacteria

Study the material in this section and then write out the answers to these questions. Do not just click on the answers and write them out. This will not test your understanding of this tutorial.

  1. Matching:

    _____ Alter bacterial 30S ribosomal subunits blocking translation. (ans)

    _____ Inhibit peptidoglycan synthesis causing osmotic lysis. (ans)

    _____ Alter bacterial 50S ribosomal subunits blocking translation. (ans)

    _____ Inhibit nucleic acid synthesis. (ans)

    1. macrolides(erythromycin, azithromycin, clarithromycin, dirithromycin, troleandomycin, etc.), oxazolidinones (linezolid), and streptogramins
    2. penicillins, monobactams, carbapenems, cephalosporins, and vancomycin
    3. fluoroquinolones (norfloxacin, lomefloxacin, fleroxacin, ciprofloxacin, enoxacin, trovafloxacin, etc.), sulfonamides and trimethoprim, and metronidazole
    4. aminoglycosides (streptomycin, neomycin, netilmicin, tobramycin, gentamicin, amikacin, etc.) and tetracyclines (tetracycline, doxycycline, demeclocycline, minocycline, etc.)
  2. Describe 4 different ways antibiotics or disinfectants may affect bacterial structures or macromolecules and state how this ultimately causes harm to the cell.
    1. (ans)
    2. (ans)
    3. (ans)
    4. (ans)
  3. Multiple Choice (ans)

4.3: Ways in which Bacteria May Resist Chemical Control Agents

Study the material in this section and then write out the answers to these question. Do not just click on the answers and write them out. This will not test your understanding of this tutorial.

  1. Name 2 bacteria that have low-permeability membrane barriers and are thereby intrinsically resistant to many antibiotics. (ans)
  2. Briefly describe 3 different mechanisms as a result of genetic changes in a bacterium that may enable that bacterium to resist an antibiotic.
    1. (ans)
    2. (ans)
    3. (ans)
  3. State what the following stand for:
    1. MRSA (ans)
    2. VRE (ans)
    3. CRE (ans)
  4. Briefly describe R plasmids and state their significance in our attempts to treat infections with antibiotics. (ans)
  5. Multiple Choice (ans)