A lipid (fatty) covering that surrounds a viral particle. It is derived from the cell membrane of the host cell when the virus buds, or exits, the infected cell. The envelope is important for entry into a host cell. Viruses with an envelope are generally less stable outside of a host than viruses that lack an envelope. Viruses that are enveloped include HIV, influenza, Ebola, dengue, and chikungunya.
A protein that acts as a biological catalyst. Enzymes are necessary to produce chemical reactions within a cell.
A disease affecting a large number of individuals within a population, community, or region at the same time
A medical scientist who studies the incidence, distribution, and control of disease in a population
The complete elimination of a disease
Organisms whose cells possess a membrane-bound structure called a nucleus that contains the genetic material (DNA)