Q: What is a capsid?
A: A capsid is the protein shell of a virus that encloses the virus's nucleic acid.
Q: What are the subunits of a capsid called and how are they structured?
A: The subunits of a capsid are called capsomeres, and they are observable in a 3-dimensional structure.
Q: How are capsids classified?
A: Capsids are broadly classified by their structure.
Q: Can the structure of a capsid vary between different viruses?
A: Yes, some viruses, such as bacteriophages, have developed more complicated structures compared to others.
Q: What are the two general shapes of a capsid?
A: The two general shapes of a capsid are icosahedral and helical.
Q: Do the capsid faces consist of only one protein?
A: No, the capsid faces may consist of one or more proteins such as the foot-and-mouth disease virus capsid faces, which consist of three proteins called VP1-3.
Q: What is the icosahedral shape of a capsid?
A: The icosahedral shape has 20 equilateral triangular faces approximating a sphere.