obligate intracellular parasites that contain either DNA or RNA

structure: may be as small as 20-30nm and are below the level of resolution of light microscopy

functions: cause illness or disease states in humans

an intact infectious viral particle; inert because it lacks components necessary for independent life and replication

structure: basic virions (naked viruses):composed of inner genome and capsid; some have outer envelope which surrounds the capsid

inner ncleic acid core that functions as the genetic material of the virus

codes for the synthesis of viral components and viral enzymes for replication

can be single or double stranded DNA or RNA( but never both)

protein shell surrounding the genome

composed of capsomeres ( protein subunits)

serves to protect and introduce the genome into host cel

come in different shapes which serves for morphological distinction

present in some virions

polypeptide backbone together with lipids and carbohydrates acquired from host cell

presence used to characterize the viruses

composed of a single type of subunit stacked around a central axis to form a helical structure

rod shaped virion

neither helical, nor icosahedral in shape

mau possess extra structures such as protein tails or a complex outer wall

hepatitis: generic term reffering to inflammation of the liver

primary viruses: A,B,C,D,E, and G

occurs in chronic and acute forms

can be asymptomatic, mild, short-lived or prolonged, severe, and ultimately fatal

acute: last 1-6mths; typical form associated with jaundice

chronic: last more than 6mths;most cases caused by hepatitis B

Fulminant Acute: rare but most serious type

subclinical hepatitius w/o jaundice: carrier state