Question

How do viruses attach themselves to host cells?

Answer 1

Hint: In the viral life cycle, entry of virus is the early stage of infection. As soon as the host cell is encountered with the virus, the viral material is introduced into the host cells.

Complete answer:
For the entry of virus into the host cell, the virus needs to be attached to the host cells. This attachment can be achieved through binding of the particular proteins present on the viral envelope or viral capsid to the specific proteins known as the receptor proteins present on the cellular membrane of the targeted cell. This cellular membrane is bounded by a phospholipid bilayer which acts as a natural barrier of the cell. Various cells present in the host or the host itself that are infected via a specific virus can be determined through this interaction specificity.
Once a virus is in a cell, it will activate formation of proteins (either by itself or using the host) to gain full control of the host cell. Suppression of transcription and translation in the host cell, suppression of cell signaling and suppression of intrinsic cell defenses are the several control mechanisms. However, the cytotoxic effects might lead to the death or deterioration of the virus infected cell.
Real time could be used for visualizing the entry of virus via employing GFP (green fluorescent protein). Inside the host cell, the virus takes some time for the adjustment prior to the start of their replication process.

Note: The protein formation is initiated either through the host or by the virus itself as soon as the virus enters the cell thus attaining complete control of the host cell.