HIV virus exists as a cone-shaped virion with a diameter of approximately 100 nanometer. Its shape would be classified as a complex virus with much flexibility in symmetry. This is an enveloped virus which means it possesses a lipid bilayer. We mentioned in class that a lipid layer that comes with being an enveloped virus is actually not as stable as being without an envelope, because this outer layer is extremely fragile. However, despite while HIV is not as resistant to the environment as non-enveloped viruses, having a lipid bilayer helps the virus avoid the host immune system because it shares a similar component with the host cell which also facilitate fusion as an entry pathway.

The viral receptor is on the lipid outer layer and requires co-receptors such as CCR5 or CXCR4 to attach to the host cell. During online class lecture, Dr. Parilla mentions that those without co-receptors have the possibility of being immune to HIV attacks. The genome of HIV virus is in the form of double stranded RNA and it possesses a reverse transcriptase which can transform RNA to DNA or DNA to RNA which is a feature of a retro-virus. Genome of HIV-1 is approximately 9.7 kb.