The main difference between virus and prion is that the virus is an infectious particle that contains a nucleic acid molecule covered by a protein core whereas the prion is a simpler infectious particle made up of only proteins. Furthermore, virus can cause a wide array of infections while prions mainly cause neuro-degenerative diseases in humans and animals.
Virus and prion are two types of infectious particles that can cause disease in humans, animals, plants or even in bacteria.
Key Areas Covered
1. What is a Virus
– Definition, Facts, Disease
2. What is a Prion
– Definition, Facts, Disease
3. What are the Similarities Between Virus and Prion
– Outline of Common Features
4. What is the Difference Between Virus and Prion
– Comparison of Key Differences
Key Terms
Diseases, Infectious Particles, Made up of, Prion, Virus
What is a Virus
A virus is an infectious particle, which is non-living. It is made up of nucleic acids covered with a protein coat called a capsid. Some viruses are covered with a lipid envelope. Since a virus is not a living organism, it does not undergo metabolism or replication within the environment. They have to infect a host cell for viral replication. Viruses may infect all forms of living cells including humans, animals, plants, bacteria, and archaea.
Figure 1: Virus Structure
Viruses exhibit two types of life cycles called lysogenic and lytic cycle in which the DNA replication and protein synthesis take place in order to produce new viral particles. Measles, mumps, chickenpox, and influenza are some viral diseases.
What is a Prion
A prion is a very simple infectious particle made up of an abnormal form of a normally harmless protein. Prions mainly cause neuro-degenerative diseases that are fatal. When infected, prions cause misfolding of normal proteins in the brain. These abnormal shapes of proteins destroy neurons causing the brain to riddle with holes.
Figure 2: Microscopic “Holes” in the Gray Matter
Prion diseases were first discovered with the ‘Mad cow disease’ in the United Kingdom. This disease can transmit to humans when they consume infected beef. Infected humans show symptoms such as personality changes, muscular coordination problems, impaired memory and thinking, and vision problems.
Similarities Between Virus and Prion
- Virus and prion are simple non-living particles.
- They invade living cells.
- They can cause severe disease conditions whit the infection.
Difference Between Virus and Prion
Definition
Virus refers to an infective agent that typically consists of a nucleic acid molecule in a protein coat and is able to multiply only within the living cells of a host while prion refers to an infectious protein particle similar to a virus but lacking nucleic acid; thought to be the agent responsible for scrapie and other degenerative diseases of the nervous system.
Complexity
Virus is a very simple particle that can infect other living cells while prion is less complex even than a virus.
Made up of
The composition of virus is a nucleic acid molecule covered by a protein coat while the composition of prion is only proteins.
Infections
Virus can cause a wide variety of infections while prions mainly cause neuro-degenerative diseases.
Conclusion
A virus refers to an infectious particle that can cause various types of diseases in living organisms while a prion is a simpler infectious particle that causes neuro-degenerative diseases. Viruses are made up of nucleic acids, which is covered by a protein coat while a prion is completely made up of proteins. The main difference between virus and prion is the structure and the type of diseases they cause.
Reference:
1. “Intro to Viruses.” Khan Academy, Khan Academy, Available Here
2. “Prion.” Biology Online, Available Here
Image Courtesy:
1. “Virus stucture simple” By GrahamColmTalk – I created this work entirely by myself. (CC BY-SA 3.0) via Commons Wikimedia
2. “Histology bse” By Dr. Al Jenny – Public Health Image Library, APHIS: (Public Domain) via Commons Wikimedia
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