BIO 315 Lecture Notes - Lecture 4: Petri Dish, Herpes Labialis, Reverse Transcription Polymerase Chain Reaction
Document Summary
Viruses before bacteria; discovered by plant biologists as they diseased plants through tabacoo mosaic virus (1900s); reed confirmed the theory that yellow fever is virus that is transmitted by mosquito (aedes)- originated in africa. 5. 1 sizes and structural features of selected viruses. Symmetry: helical virus (ebola), icosahedral (adenovirus, polio), irregular (phages have nucleocapsid, tail, fibers and pin which is attached to bottom of cell and helps to attach to bacteria so that it could transfer genetic material) Envelopes have spikes outside it- proteins that recognize host cell receptors- viruses constantly change the spikes to allow it to infect host cell over and over again (combats antibodies because memory cells only recognize unchanged version of virus) Entry most crucial- into animals (endocytosis, membrane fusion, enveloped virus by endocytosis)- overcome host cw (needs cw to be damaged like insects feeding on plants, cannot enter directly otherwise) Nucleocapsid removed by host ph in late endosome and lysosome.
