Microbiology Test 2 Test Questions – Flashcards
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Unlock answersmode of action for:
Aminoglycosides |
| Binds to 30S ribosomal subunit of bacteria |
mode of action:
sulfonamide |
| Inhibits a metabolic pathway |
mode of action:
polymixin-B
|
| Disrupts cell membranes |
mode of action:
Vancomycin |
| Inhibits cell wall synthesis |
mode of action:
macrolides |
| Binds to 50S ribosomal subunit of bacteria |
At the end of glycolysis, the end product is a __________ carbon molecule 1. name product 2. how large |
1. Pyruvate 2. 3 carbon molecule |
| Characteristics of Fermintation |
-produces gases, alcohols and acids - occurs in the absence of oxygen - occurs following glycolysis |
What is the terminal electron acceptor in anaerobic respiration?
|
| Sulfur or nitrogen compounds |
The greatest amount of NADH (reduced to NAD+) is produced during_______ stage of aerobic respiration.
|
| Tricarboxylic acid cycle (TCA) |
| when is membrane filtration used? |
when # are too low for serial dilution (plate count) |
| What is turbidity? |
-measures light transmitted through sample with spectrophotometer - limitation: must have high number of cells |
| What antibiotic binds to 30S ribosome of bacteria preventing attachment of tRNA? |
| tetracycline |
| (T/F) Tubulin is an important component of prokaryotic flagella. |
| false |
A common target of anti fungal drug is:
|
| Ergosterol |
| define: batericidal |
| agent that kills veg. cells but not endospores |
| define: bactereiostatic |
| agent that prevents/ retards multiplication of bacteria but doesnt always kill it |
| define: Disinfection |
| eliminates most pathogens; used on inanimate objects |
| define: pasteurization |
| brief heat treatment used to reduce organisms that cause food spoilage |
| define: Decontamination |
| treatment to reduce pathogens to level considered safe |
| define: sanitized |
| implies a substantially reduced microbial pop; not specific level of control |
| What are bacterial endospores resistant to? |
| heat, drying, numerous chemicals |
| what are protozoan cysts/oocyts ? |
resistant microbes in feces
|
What are mucobacterium species?
|
| cell wall initiates resistance |
| what are pseudomonas? |
| grow in presence of chemical disinfectants |
Factors affecting killing of microorg.:
|
- time of application of agent - concentration of agent - temp - presence of other materials |
Using alcohol as a control unit: what are its fxns? |
kill- veg. bacteria/ fungi how- damage lipid membrane limit- evaporates quickly/ damages rubber |
Using aldehydes as control unit:
|
kill bacteria/ inactive viruses they inactive protein/ DNA ex. formalin--- formaldehyde |
| how are halogens used for control? |
oxidizes proteins uses chlorine to destroy all organisms/ disinfectant ex. iodine-- kill veg. cells |
| How is ethylene oxide used as a control unit? |
gaseous sterilant useful for hospitals to sterilize equip that cant be heated - kill everything - react w proteins |
| Metals as a chemical control |
limit mutagenic/ potentially carcinogenic reacting with proteins combing with enzymes and intefere w fxn |
| What is often used as an alternative oxidizer compared to chlorine? |
| ozone |
What are the B- lactam drugs and fxns?
|
PCN & cephalosporins 1. inhibit peptide bridge formation 2. some org resis effects from B- lactamase enzyme
|
| two groups of B-lactam drugs: |
Carbapenems- effective agains wide range of gram +/-
Monobactams- effective against Enterobacteriaceae |
| What are the fxns and characteristics of Vancomycin? |
| prevents formation f PTG and cell wall construction * must be given intravenously due to poor abs in intestinal tract |
| What are the fxns of Bacitracin? |
interferes with transport of PTG precursors across CPM * topical only-- very toxic |
| These irreversibly binds to 30S ribosomal units: |
| Aminoglycosides |
| tetracyclines |
reversiby bind 30S ribsomal subunit - effective against gram +/- - longer half-life so less freq dose
|
| macrolides |
reversibly bind to 30S ribosomal subunit - gram + and atypical pneumonia - |
| Chloramphenicol |
reversibly bind to 50S ribosomal unit - last resort drug---- causes aplastic anemia |
| Lincosamides |
binds to 50S ribosomal unit inhibits gram +/- - treats infections from interstinal perforation ** clindamycin most common |
| Fluroquinolones |
inhibit action of topoiomerase DNA gyrase effective against gram +/-
|
| Riframycins |
block prokaryotic RNA polymerase or initation of transcription - primarily used to treat TB |
| Sulfonamides |
inhibit growth of gram +/- resistance due to plasmid human cells lack enzyme in folic acid pathway |
| Trimethroprim |
inhibits folic acid production - used as synergist of sulfonamide |
| polymyxin-B |
most common- first aid ointments - topical - binds to membrane of gram |
| Polyenes |
| produced by streptomyces; disrupts fungal membrane---- very toxic to humas--- limited to life treatening diseases |
| Azoles |
chem. synthesized drug 1. imidazoles--> inhibit sythesis of ergosterol (cream) 2. Triazole--> inhibit synthesi of ergosterol; increased in used for infections |
| allyamines |
inhibit pathwa of ergosterol synthesis topical used for dermatophyte infections
|
| Echinocandins |
| interfere with sn of component of fungal cell wall |
| Griseofulvin |
interfere w action of tubulin skin/ nail infection |
| flucytosine |
| inhibits enzymes required for nucleic acid syn |
| What is the overall product at the end of glycolysis? |
| 4 ATP; 10 NADH, 2 FADH |
