what is that bothering host cell machinery to follow instructions of virus(either DNA or RNA)after infection??

Answer 1

Different viruses have different mechanisms to cause the cell to switch from following the host cell's instructions, to following the virus' instructions. Some viruses (a few that infect bacteria) have enzymes that break down the host cell's DNA, so the only DNA left is the virus'. In this case the virus DNA is not broken down because its DNA is modified slightly so that the enzymes do not recognize the virus DNA.

Other viruses use other mechanisms. In order to be "read", cellular messenger RNA has to have a "cap" structure at its beginning. Some viruses, like the one that causes the flu, "steal" this host cap and use it to make viral RNA. This process, called "cap snatching", makes the host mRNA useless, so only the viral mRNA is available.

Other viruses have proteins that serve to shut down host synthesis.

Answer 2

There are two general mechanisms by which viruses usurp or (bother) cellular machinery.
Whenever a DNA virus enters the host cell, the viral DNA finds the DNA polymerase of the host and multiplies its DNA.Then follows the transcription of viral DNA to form RNA. These get translated in the host ribosomes to produce viral proteins at the cost of host cells resources very fast.
In case of RNA virus, the injected RNA has reverse transcriptase.Upon the entry into host cytoplasm it uses host cells' resources to manufacture DNA which is integrated into the host genome and then used in usual way to make viral proteins and RNA for its reproduction. All these happen very fast at the expense of the cell and the cell gets robbed and is finally destroyed.

Answer 3

I believe it has to do with the sequencing. A DNA sequence (sometimes genetic sequence) is a succession of letters representing the primary structure of a real or hypothetical DNA molecule or strand, The possible letters are A, C, G, and T, representing the four nucleotide subunits of a DNA strand (adenine, cytosine, guanine, thymine), and typically these are printed abutting one another without gaps, as in the sequence AAAGTCTGAC. This coded sequence is sometimes referred to as genetic information. The virus injects it's own code sequence into that of the infected host causing replication of it's own genetic information instead of that of the host.

Answer 4

Virusses are unique among all the living things as they cann't replicate outside a cell. A virus in order to replicate itself attaches to the outer layer of the living cell usually by the process of adsorption. Now, using some lytic enzymes, it lyses the cell membrane of the host cell and then injects its genetic material into it. These materials find their path to the nucleus of the host cell and once in the nucleus, they integrate themselves in the genetic material of the host cell. This process is known as SPLICING and the enzyme used for this process by viruses is INTEGRASE. Now along with the DNA of host cell, they also get replicated. These sequences of the viral genetic material code to the formation of proteins used to form the protein coat of the virus. Now as the proteins form, copies of the genetic material forms a new virus along with the newly formed proteins. These new viruses get out of the cell by lysing its cell membrane.
The major difference in the replication mechanism of RNA and DNA viruses is that, the genetic material of the DNA virus, which is a segment of DNA, can integrate directly to the genetic material of the host cell, but in case of RNA viruses, the genetic material being RNA, must be converted to the corresponding DNA sequence to be integrated to the genetic sequence of the host cell. For this, viruses uses a mechanism known as REVERSE TRANSCRIPTION catalised by the enzyme REVERSE TRANSCRIPTASE. This enzyme is produced by the virus and injected in the host cell along with its genetic material.
This is a brief description of the mechanism by which a virus infects the host cell.Virusses are unique among all the living things as they cann't replicate outside a cell. A virus in order to replicate itself attaches to the outer layer of the living cell usually by the process of adsorption. Now, using some lytic enzymes, it lyses the cell membrane of the host cell and then injects its genetic material into it. These materials find their path to the nucleus of the host cell and once in the nucleus, they integrate themselves in the genetic material of the host cell. This process is known as SPLICING and the enzyme used for this process by viruses is INTEGRASE. Now along with the DNA of host cell, they also get replicated. These sequences of the viral genetic material code to the formation of proteins used to form the protein coat of the virus. Now as the proteins form, copies of the genetic material forms a new virus along with the newly formed proteins. These new viruses get out of the cell by lysing its cell membrane.
The major difference in the replication mechanism of RNA and DNA viruses is that, the genetic material of the DNA virus, which is a segment of DNA, can integrate directly to the genetic material of the host cell, but in case of RNA viruses, the genetic material being RNA, must be converted to the corresponding DNA sequence to be integrated to the genetic sequence of the host cell. For this, viruses uses a mechanism known as REVERSE TRANSCRIPTION catalised by the enzyme REVERSE TRANSCRIPTASE. This enzyme is produced by the virus and injected in the host cell along with its genetic material.
This is a brief description of the mechanism by which a virus infects the host cell.