- Can viruses produce toxins?
- What triggers a virus?
- Do viruses excrete toxins?
- What do viruses feed on?
- What makes a virus inactive?
- Do viruses lie dormant in the body?
- What does it mean when a virus is latent?
- Do viruses die in air?
- Are viruses living?
- Can viruses reactivate?
- How does viruses enter the body?
- What is the largest virus known?
- How do you kill a DNA virus?
- How do virus die?
- At what temperature do viruses denature?
- What is not true about viruses?
Can viruses produce toxins?
There is only one viral toxin that has been described so far: NSP4 from rotavirus..
What triggers a virus?
Bacterial and viral infections have many things in common. Both types of infections are caused by microbes — bacteria and viruses, respectively — and spread by things such as: Coughing and sneezing. Contact with infected people, especially through kissing and sex. Contact with contaminated surfaces, food, and water.
Do viruses excrete toxins?
Disease occurs only if the virus replicates sufficiently to damage essential cells directly, to cause the release of toxic substances from infected tissues, to damage cellular genes or to damage organ function indirectly as a result of the host immune response to the presence of virus antigens.
What do viruses feed on?
Viruses rely on the cells of other organisms to survive and reproduce, because they can’t capture or store energy themselves. In other words they cannot function outside a host organism, which is why they are often regarded as non-living.
What makes a virus inactive?
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.
Do viruses lie dormant in the body?
Virus latency (or viral latency) is the ability of a pathogenic virus to lie dormant (latent) within a cell, denoted as the lysogenic part of the viral life cycle. A latent viral infection is a type of persistent viral infection which is distinguished from a chronic viral infection.
What does it mean when a virus is latent?
When a virus is present in the body but exists in a resting (latent) state without producing more virus. A latent viral infection usually does not cause any noticeable symptoms and can last a long period of time before becoming active and causing symptoms.
Do viruses die in air?
A cold virus can sometimes survive on indoor surfaces for several days, although its ability to cause infection drops dramatically over time. Flu viruses can survive in the air for several hours, especially at lower temperatures, and on hard surfaces they can survive and remain infectious for 24 hours.
Are viruses living?
So were they ever alive? Most biologists say no. Viruses are not made out of cells, they can’t keep themselves in a stable state, they don’t grow, and they can’t make their own energy. Even though they definitely replicate and adapt to their environment, viruses are more like androids than real living organisms.
Can viruses reactivate?
The genome of a virus that causes latent infection of cells must be transcribed and translated into viral proteins. This occurs when the virus is reactivated from a latent stage to a lytic stage. Certain viral genes that are specific to each virus initiate this reactivation process.
How does viruses enter the body?
Microorganisms capable of causing disease—or pathogens—usually enter our bodies through the eyes, mouth, nose, or urogenital openings, or through wounds or bites that breach the skin barrier. Organisms can spread, or be transmitted, by several routes.
What is the largest virus known?
MimivirusMimivirus is the largest and most complex virus known.
How do you kill a DNA virus?
The major way bacteria defend themselves from bacteriophages is by producing enzymes which destroy foreign DNA. These enzymes, called restriction endonucleases, cut up the viral DNA that bacteriophages inject into bacterial cells.
How do virus die?
Strictly speaking, viruses can’t die, for the simple reason that they aren’t alive in the first place. Although they contain genetic instructions in the form of DNA (or the related molecule, RNA), viruses can’t thrive independently. Instead, they must invade a host organism and hijack its genetic instructions.
At what temperature do viruses denature?
Viruses are inactivated at temperatures between 60 °C and 65 °C, but more slowly than bacteria. However, as shown for poliovirus and hepatitis A, as temperatures increase above 70 °C, a greater than 5 log inactivation (99.999% reduction) is achieved in less than 1 minute.
What is not true about viruses?
In fact, viruses should not even be considered organisms, in the strictest sense, because they are not free-living—i.e., they cannot reproduce and carry on metabolic processes without a host cell. All true viruses contain nucleic acid—either DNA (deoxyribonucleic acid) or RNA (ribonucleic acid)—and protein.