Table of Contents
- 1 When a virus is in an inactive state?
- 2 What happens when a virus enters a host cell?
- 3 What part of the bacteriophage actually enters the host cell?
- 4 How do viruses become inactive?
- 5 What are three major ways in which a virus enters a host cell to deliver its genome?
- 6 How does a virus replicate in a host cell?
- 7 What are hidden viruses?
- 8 Which part of a virus determines which host cell it can infect?
- 9 How does herpes simplex 1 hide from the immune system?
- 10 How does a virus insert itself into a cell?
- 11 How does HSV 1 evade the immune system?
When a virus is in an inactive state?
A latent infection is one where a virus is not actively replicating but is instead “sleeping” until a better time to replicate.
What happens when a virus enters a host cell?
During attachment and penetration, the virus attaches itself to a host cell and injects its genetic material into it. During uncoating, replication, and assembly, the viral DNA or RNA incorporates itself into the host cell’s genetic material and induces it to replicate the viral genome.
How do the hidden viruses multiply?
For viruses to multiply, they usually need support of the cells they infect. Only in their host´s nucleus can they find the machines, proteins, and building blocks with which they can copy their genetic material before infecting other cells.
What part of the bacteriophage actually enters the host cell?
The nucleic acid of bacteriophages enters the host cell “naked,” leaving the capsid outside the cell. Plant and animal viruses can enter through endocytosis (as you may recall, the cell membrane surrounds and engulfs the entire virus).
How do viruses become inactive?
We now see that there are at least three ways that a virus can become inactive. Any disruption of the structure of key proteins, nucleic acids or the fatty membrane will render it incapable of infecting cells. What then happens to a virus particle, also known as a virion, that lands on a surface? Many possibilities.
How do viruses get inactivated?
Many viruses contain lipid or protein coats that can be inactivated by chemical alteration. Viral inactivation is different from viral removal because, in the former process, the surface chemistry of the virus is altered and in many cases the (now non-infective) viral particles remain in the final product.
What are three major ways in which a virus enters a host cell to deliver its genome?
Entry. Virus enters cell by endocytosis. In the cytoplasm, the capsid comes apart, releasing the RNA genome….The cell lyses (bursts), releasing the viral particles, which can then infect other host cells.
- Genome replication and gene expression.
How does a virus replicate in a host cell?
Viruses cannot replicate on their own, but rather depend on their host cell’s protein synthesis pathways to reproduce. This typically occurs by the virus inserting its genetic material in host cells, co-opting the proteins to create viral replicates, until the cell bursts from the high volume of new viral particles.
Where do viruses multiply?
Viruses multiply only in living cells. The host cell must provide the energy and synthetic machinery and the low- molecular-weight precursors for the synthesis of viral proteins and nucleic acids.
This occurs when viruses that are in a dormant, or ‘latent’, state become reactivated. Characterized by limited gene expression and zero viral replication, latent viruses remain hidden from the immune system and are not affected by antiviral drugs, unless they are reactivated.
Which part of a virus determines which host cell it can infect?
A virus attaches to a specific receptor site on the host cell membrane through attachment proteins in the capsid or via glycoproteins embedded in the viral envelope. The specificity of this interaction determines the host—and the cells within the host—that can be infected by a particular virus.
How do viruses leave the host cell?
Viruses can be released from the host cell by lysis, a process that kills the cell by bursting its membrane and cell wall if present.
How does herpes simplex 1 hide from the immune system?
New research reveals how the common virus that causes cold sores – herpes simplex 1 – invades our cells and takes control of their machinery to replicate itself and hide from the immune system. Viruses insert their DNA into host cells and use their machinery to make copies of themselves.
How does a virus insert itself into a cell?
Viruses insert their DNA into host cells and use their machinery to make copies of themselves. The discovery is significant because it offers new information about how the virus affects processes in the cell rather than the immune system.
How does the herpes virus stay dormant in the body?
Working first with a mouse model, and then repeating the results in humans, the team found that after initial infection, the host protein interferon gamma kept the virus dormant in the body. But this effect was canceled following an infection from a worm parasite.
How does HSV 1 evade the immune system?
The new study investigates in detail how HSV-1 manages to do this and evade detection by the immune system, which normally spots cells behaving abnormally and kills them before they can do too much damage. The study team used cultures of fibroblasts – a type of human connective tissue cell.