The Healthy Dose – Viruses

By Parth Dwivedi

Viruses find themselves all over the news and in our lives. Measles returned from near eradication in large urban areas due to the misguided anti-vaccination movement and Ebola outbreaks have been stirring up a frenzy in Western Africa.

Please note, while Ebola was supposed to be the topic of this installment, I saw a discussion of it less meaningful before properly understanding some basic points about viruses in general. Let’s jump right into it.

Viruses are difficult to categorize; they represent a grey area when it comes to being alive. They are not quite living things, since they do not have the ability to sustain their own lifecycles and depend on other living things to do so. However, they have at least one characteristic absolutely necessary to be considered living—the tendency to protect and spread the information needed for them to operate.
Wait, life requires information? This is beginning to sound like computer programming.

Let’s talk about it some more.
Viruses contain nucleic acids like DNA and RNA. These molecules are ways for cells to store and transfer information. DNA is what tells the cell how to create the machines that allow it to function, but such valuable information needs to stay protected and is therefore difficult to access and cannot be moved anywhere else. This problem is solved by DNA copying its information into RNA, which can be moved and accessed. If DNA is a computer’s hard drive then RNA is a flash drive.

Nature has found very clever ways for viruses to transfer their own viral information into a cell, essentially hacking into it. Once inside, they use the cell’s own machinery to produce viral material. There is a reason that dangerous self-replicating computer programs were named after these biological hackers.

Some of these hacking mechanisms can be fairly simple, like eating through a small portion of the cell before injecting nucleic acids into it. Others can be much more elegant: many viruses are known to coat themselves in proteins that resemble host proteins. These viruses become virtually invisible to the host’s immune system by disguising themselves. The most dangerous bad guys are the ones that make no noise while they work.

Once inside, viral DNA can be incorporated into host DNA, making it harder to discover; viral RNA can be converted to DNA for long-term effects and replicated for quicker effects. After hijacking the cell, virus particles either burst out from it or slowly bud outward—if you have ever seen small bubbles coming together to form a larger bubble, then it is the opposite of that. Thus, we can see that viruses use the cell to destroy itself.

Join us for our next installment, when we discuss Ebola.