Introduction Viral Structure Virology Introduction Viral Structure

Virology - Introduction Viruses are obligate intracellular parasites Viruses are considered nonliving because they cannot reproduce on their own Viruses contain DNA or RNA either of which is double or single stranded

Virology - Introduction Host Range Refers to range of tissue virus can infect Most viruses can only infect a specific type of tissue within a host Host range is determined by receptors found on found on tissue cell surfaces

Virology - Introduction Viral Size Determined by electron microscopy; viruses cannot be seen under light microscope Viruses range from 20 to 10000 nm

Defenses - Interferons Antiviral proteins 3 types alpha, beta & gamma Produced by virus infected cell and migrate to uninfected cells that then produce antiviral proteins Host cell specific but not virus specific