What is the function of the capsid?
Viruses are composed of two main parts: an outer protein covering called a capsid and an inside core of either DNA or RNA.
Not both DNA and RNA.
Some of these have an envelope over the capsid. The ones that do not are said to be naked. The proteins in the capsid allow the virus to attach to the matching "docking stations" proteins of the host cell.
The naked viruses are more resistant to changes in the environment.
Some naked viruses include poliomyelitis, warts, the common cold, chickenpox, shingles, mononucleosis, herpes simplex (cold sores), influenza, herpes viruses and HIV (AIDS).
Some enveloped viruses include norovirus (stomach bug), rotavirus and human papillomavirus (HPV).
The envelope can be damaged by freezing temperatures, chlorine, and phenol. If damaged the virus cannot infect.