What are the primary components of a viral capsid?

The primary components of a viral capsid are proteins. The capsid serves as the protective outer shell of a virus, and its primary function is to encase and protect the viral genetic material (which is either DNA or RNA). Capsids are made up of protein subunits called capsomers, which assemble into a specific structure to provide both structural support and protection against environmental factors.

While nucleic acids are indeed essential components of viruses, they are not part of the capsid structure itself but are rather contained within it. Lipids and carbohydrates do not generally form a part of the viral capsid in the same way proteins do; they may contribute to viral envelopes in some types of viruses but are not fundamental components of the capsid structure.

Thus, focusing on the structural role within the virus, proteins are the primary building blocks of the viral capsid.