Ultrastructure
Like other coronaviruses, SRAS-CoV-2 is made up of four proteins [13], [14].
Spike (S) protein forms the namesake crown-like protuberances that are essential to attach the virus to the host cell and determine which cells it targets. Envelope (E) protein forms the envelope. Membrane (M) protein forms the membrane. Nucleocapsid (N) protein protects the viral RNA. Proteins S, E and M together enclose the virus.
Once the virus has penetrated the host cell, its RNA is released, and copies are produced. The resulting virions burst out and spread to other cells, where the process is repeated.