Figure 1. Schematic diagram of SARS-CoV-2 showing its basic component proteins along with its receptor binding site, angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease (TMPRSS2).

The virus consists of a spherical membrane (shown in white and grey) which constitutes membrane protein (shown in orange), spike protein (shown in red), hemagglutinin esterase (shown in blue), and envelope small membrane protein (shown in yellow). The spike protein binds to the ACE2 receptor of the host cell after being activated by the proteolytic cleavage activity of TMPRSS2.