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23 Cards in this Set
- Front
- Back
Describe detergents
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amphipathic compounds with two parts
- A non-polar (a long hydrocarbon chain) that attaches to grease - A polar part that is attracted to water |
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Describe detergent types
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Anionic detergents = The active part has a negative charge
- Include soaps - Are effective cleansers, but have little antibacterial effects 2. Cationic detergents = The active part has a positive charge - Example: Quaternary Ammonium Compounds - Benzalkonium chloride, Zephiran - Have great antibacterial effects in the absence of contaminating organic matter - Used as antiseptics, and disinfectants - Act by disrupting membranes mainly |
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Describe Phenol
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Act by disrupting membranes and denaturing proteins
• Phenol was the first widely used antiseptic and disinfectant - The father of antiseptic surgery was Joseph Lister - Its use is now limited because of its odor and skin irritation |
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Describe Phenolics
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Act by disrupting membranes and denaturing proteins
Cresols - active ingredient in Lysol Halogenated phenols - work even in presence of organic contaminating matter Triclosan-broad spectrum antibacterial/antifungal agent. Blocks lipid synthesis |
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Describe Alcohols
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dissolve membrane lipids and denatures proteins
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Describe halogens
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act as oxidizing agents; may denature protein
5: Fluorine, Bromine, Chlorine, Iodine, Astatine |
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Describe alkylating agents
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alkylating proteins and NA's
Formaldehyde.37% solution=formalin -used for germicide, inactivate viruses for vaccines Gluteraldehyde. 2% solution=CIDEX -liquid sterilient Ethylene oxide - highly penetrating gaseous sterilant |
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Describe Heavy Metals
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denature proteins. extremely small amounts can be lethal (oligodynamic action)
organic mercuric compounds - mercurochrome silver nitrate - drops used for baby's eyes to fight Neisseria gonorrhoeae Copper Sulfate - to control algal growth |
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Describe Organic Acids
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low pH denatures proteins
Propionic acid = antimicrobial in bread, cheese Lactic acid = antimicrobial in yogurt, pickled foods Benzoic acid = Antimicrobial in margarine, relishes Acetic acid = vinegar |
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Antibiotic producers are divided into these groups:
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Actinomycetes - Streptomyces
Molds - Penicillium Bacteria other than Actinomycetes- Bacillus |
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This antibiotic can affect Gram + and Gram -
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tetracycline
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This is used against Mycobacterium tuberculosis
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isoniazid
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Describe penicillins
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- beta-lactam antibiotics
- Inhibit the transpeptidation reaction - Natural penicillins - Include Penicillin G - Effective mainly against Gram-positive bacteria |
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Describe semisynthetic penicillins
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Effective against Gram-negative bacteria
- Example: Ampicillin - Resistant to penicillinases - Example: Methicillin - Unfortunately, MRSA strains have appeared! |
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Describe cephalosporins
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beta-lactam antibiotics
- Inhibit the transpeptidation reaction - Divided into four “generations” depending on their effectiveness against Gram-negative bacteria - The later generations are generally more effective against Gram-negative bacteria and less susceptible to destruction by beta-lactamases |
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Describe Vancomycin
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Vancomycin
- NOT BETA-lactam antibiotics - Inhibits transport of the cell wall precursors by the carrier - Effective against enterococci, but alas VRE strains have evolved! - The only drug that is effective against MRSA BUT NOW THERE IS VRSA |
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Describe polymyxins
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have a cationic detergent mode of action
generally more effective against Gram - |
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Describe streptomycin
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inhibits protein synthesis at the 30S subunit
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Describe tetracycline
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inhibits protein synthesis at the 30S subunit
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Describe erythromycin
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inhibits protein synthesis at the 50S subunit
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Describe chloramphenicol
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inhibits protein synthesis at the 50S subunit
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This is the steps for the future of drug discovery:
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1) genomics - use genome data to ID new targets
2) rational drug design - design drugs to interact at the active site of an enzyme 3) nanotubes - use of small cyclic peptides that form tubes within membranes 4) combinatorial chemistry - create and test random variations of a molecule |
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Describe the anti-fungal antibiotics
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Inhibition of cell membrane synthesis:
Azoles Terbinafine Tolnaftate Disruption of cell membrane: Amphotericin B Nystatin Inhibition of NA synthesis: 5-fluorocytosine Inhibition of microtubule assembly: Griseofulvin Inhibition of cell wall synthesis: Caspofungin |