BIO 326R 1st Edition Lecture 30 Outline of Last Lecture I. Antibioticsa. Resistance i. Mechanismsb. EcologyII. Virusesa. Differ from cellsi. Sing and double stranded DNA and RNAii. + and - polarityb. Naked vs. envelopedOutline of Current Lecture I. Virusesa. Historyb. Growing virusesi. QuantifyingII. Prions Current LectureViruses- Virome= virus ecologyo Open ocean sequenced and there’s 10 million bacteriophage/mL water About 1000 phage per bacteria in the ocean- Historyo Tobacco mosaic virus (TMV)—plant virus, first discoveredo Koch’s postulates for defining a pathogen (1890) The microbe must be found in all organisms suffering from the disease, but not healthy organismsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute. The microbe must be able to be isolated from a diseased organism and grown in pure culture The cultured microbe must cause disease when introduced into a healthy organism The microbe must be re-isolated from the inoculated, diseased organism and shown to be identical to the microbe from pure cultureo TMV plant virues First discovered—discovered in 1800s by Mayer- Grind up leaves from infected plants and transmit disease into new plants- Told him that this was an infectious disease Ivanofsky—filtered ground up leaves through chamberland filter- = filters out bacteria- Believed it was just very small bacteria Beijerinck—replicated Ivanofsky experiments, applied the term virus- First human virus worked on—yellow fevero Walter Reedo Mosquito borne- Growing viruseso Originally grown in fertilized chicken eggso Tissue culture, monolayers of animal cellso Bacteriophage= grow on bacterial culture- Quantifying bacteriao Count viral particles with electron microscopeo Plaque forming units—plate dilutions of virus on cell monolayers count zones of clearing- Cancer causing viruses existo Ex: HPV cervical cancerPrions- Presence of nucleic acids prions have none- Infectious agent only composed of protein- Misfolded protein, contains mostly beta-pleated sheets (very stable)- No enzymatic activity- Amyloids= proteins that make strong elongated structureso Associated with Alzheimers- Propogate by causing other proteins to refold with a similar structure to themselves- Difficult to destroyo Use 10% bleand for one hour then heat at high temperature
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