The coronavirus has quite the complicated structure, it is in the form of an enveloped RNA virus. Firstly to understand the form of an enveloped virus compared to that of a non-enveloped virus.
A virion is a particle that consists of a viral genome either of DNA or RNA. It is protected by a capsid which is a protein layer. An enveloped virus has an additional layer-the outermost-, a biological membrane. This creates an “envelope” space between the two layers called a lipid bilayer made of lipids and proteins. The virion can only be harmful if it is assembled, this means if the envelope is not present the virus is no longer destructive. For the virus to work the capsid needs to be secure enough so that the genome is sufficiently labial to be released into the cell of the host. A capsid is created of many subunits known as
capsomers. These capsomers attach to each other in a process called self-assembly. The subunits are bonded in a weak non-covalent manner, and if left unprotected in a thermal area dissociation can occur. This structure decreases surface charge in polarity and increases the contact surface area. It decreases the energy of the capsid system and acts as the force of the self-assembly process. The energy stored in the order of the system increases and therefore heightens the chance of the virus being released. However, that is not the only method of the virus being uncoded. The virus can be released through mechanical traction and fluctuations of pH levels within the body. Ultimately, however, the final release into the host’s body depends upon the virus and the cell it tries to release itself in. There are two other crucial roles that the capsid plays apart from protecting the virion. It is also responsible for protecting the nucleic acid from being digested by their enzymes and it has sites where the virion can easily attach to the host’s cells.
An envelope increases the sensitivity of the virus due to the fragility of biological membranes. Not only that, but enveloped viruses, in general, are also a lot more sensitive than non-enveloped viruses. There are many conditions in which enveloped viruses cannot survive in. They are highly sensitive to extreme pH levels and hence, do not enter the body through the gastrointestinal tract. Other substances and circumstances they cannot withstand are heat, dryness, and disinfectants such as ethanol and propanol. As a result of this, it makes them accessible targets to hygiene. This basically means that as long as we stay vigilant and always wash our hands after going outside, the virus will not be able to sustain itself in our body. Since the biological membrane acquired from the host’s cell; usually from the endoplasmic reticulum or Golgi apparatus. This makes the host’s immune system a difficult target and it can exit the cell without lysis. The envelope helps avoid the immune response from the body which makes these viruses more dangerous compared to those non-enveloped viruses.
Baltimore Classification is a system in which viruses are categorized based upon their genome structure. It was developed by Nobel Laureate David Baltimore in the early 1970s. Coronaviruses are a form of an RNA virus and belong to the fourth group of the Baltimore
Classification system. RNA can be quite puzzling as there can be double-stranded positive viruses and single-stranded negative viruses. Negative RNA viruses have to first be converted into positive-sense single-stranded RNA before it can be transported to the host. RNA viruses have a small genome and are strongly dependent on the host, however, an advantage for the virus is that it can replicate itself within the host rapidly. Despite that, if the virus is damaged inside the host it is unlikely that it will be repaired as there are no repair mechanisms. This gives RNA viruses high mutation rates. High mutation rates make viruses quite deadly as the chances of vaccinations protecting the host is extremely rare.
So… how IS the world combatting this virus unknown to mankind and changing perceptions on the daily? Of course, immediate measures such as disinfecting surfaces and wearing masks have taken place. The closing of borders as well as nationwide lockdowns has contributed to slowing the spread of the virus. However, in terms of a vaccine, it may take until the end of the current outbreak until the vaccine is available for the general population to take. This is because firstly a vaccine has to be found, secondly, trials have to be made before it is approved and thirdly mass production of these vaccines would have to take place. So as of now, all that’s left is to take the necessary precautions and hope that with time immunity evolves.
“Baltimore Classification.” Wikipedia, Wikimedia Foundation, 17 June 2020, en.wikipedia.org/wiki/Baltimore_classification.
Molecular Expressions Cell Biology: Virus Structure, micro.magnet.fsu.edu/cells/virus.html.
PS;, Masters. “The Molecular Biology of Coronaviruses.” Advances in Virus Research, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/16877062/.
AMBOSS: Medical Knowledge Distilled. “Viruses- Part 1: Enveloped and Non-Enveloped Viruses.” , YouTube, 25 Jul. 2018.
AMBOSS: Medical Knowledge Distilled. “Viruses- Part 2: DNA vs. RNA Viruses.” , YouTube, 1 Aug. 2018.