BSC 431 Study Guide - Midterm Guide: Cytotoxicity, Toxic Shock Syndrome, Rheumatic Fever
22 Mar 2016
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Document Summary
Infectious diseases are complex; few cause just one disease. Viruses: smallest infectious particles, rapid replication and destruction of the cell, possible genomic integration. Parasites: eukaryotic, complex life cycles (cid:1) Koch"s postulates: organism must be in diseased but not healthy animals, must be isolated and grown, pure culture must reproduce disease, organism must be reisolated from infected animals (cid:1) (cid:1) (cid:1) (cid:1) Both gram positive & negative have a peptidoglycan layer: crosslinking is catalyzed by transpeptidase, target of penicillin. Layers of gram positive cell wall: cytoplasmic membrane, cell wall (thick & crosslinked) Layers of gram negative cell wall: inner cytoplasmic membrane, thinner peptidoglycan layer. Murein lipoprotein: outer membrane (lipid bilayer) Gram negative cell wall is better at blocking the passage of potentially harmful substances (cid:1) Flagella- long flagellin protein tail: aids in chemotaxis. Pili- shorter, hair-like: adherence factors (facilitated by adhesins, sex pili (transfer of genetic material) Capsules: glycocalyx, immune cells can"t phagocytize. Pathogenicity islands (set of genes encoding disease factors)
