Question

how does the coronavirus replicate its genome and expresses its genes?

How come coronaviruses are able to mutate so rapidly?

Answer 1

Answer-

How does the coronavirus replicate it's genome and Express its Gene's?

1. Coronavirus binds to host cell membrane via its S-protein and this viral protein interacts with N-acetyl muraminic acid receptor of host cell membrane. And by this virus gets entry into host cell.

2. After entry, viral genome is released into host cell cytosol where this genome directly used for production of viral proteins because coronavirus has single stranded positive sence RNA as genome that is directly used for protein synthesis by host cell.

3. Firstly, virus synthesizes it's own RNA polymerase using host machinery and then this viral RNA polymerase only recognizes and synthesizes viral RNA's. The product of viral RNA polymerase is minus RNA strand which is produced by using positive strand.

4. Further, this negative RNA is used to synthesize smaller sub genomic positive RNA's that further synthesizes all viral proteins. This negative RNA is also used to synthesize positive RNA genomes.

How come coronavirus are able to mutate so rapidly?

1. Coronavirus contains RNA as genetic material and when virus copies its genetic material it cannot proofread the correct sequence so that some mistakes remain in RNA. These mistakes remained after RNA replication is mutation. Due to this, this virus containing RNA as genetic material can mutate rapidly as compared to other viruses.

2. Some mutations are neural that means effect on protein is neutral and this mutation does not affect viral survival and circulates without any noticable effect. But other mutation shows harmful effects on it's own survival and these generations are eliminated through natural selection.

3. Some mutations helps to virus to survive better in environment and to spread more efficiently. The infectiousness and severity of disease is controlled by multiple genes in the genome and each of gene contributes spread of virus in multiple ways.

4. This continuous mutations in genome causes ineffectiveness of vaccines and lead to vaccine resistance.