When the alarm clock breaks my slumber, I roll down on my bed, blindly crawling towards my alarm clock as if it was a bomb to diffuse it. After multiple snoozes, I relinquished my dreams and come to my senses. Gulping water after I wake up is my first activity. Next, I excuse myself to the bathroom for “nature call”. All living things from a simple bacteria to a giant dinosaur needs to perform two basic life function; eat and excrete.
Since our world has been ravaged by covid pandemic lately, I wanted to discuss viruses. As a child, I often wondered, does a virus poop?
What’s a virus? It’s a bundle of genetic material (RNA or DNA) wrapped in a protein capsule called capsids. The virus seems to live a stark opposite twin life; inside and outside of a host cell.
Outside the host cell, viruses are at best not alive. They don’t grow, reproduce, metabolize or maintain a constant internal temperature. They don’t need nutrition and thus have no excretion. So viruses can’t poop, unlike bacteria.
However something remarkable thing happens when a virus invades a host cell. It hijacks the cellular process to produce a virally encoded protein that will replicate the virus’s genetic material. So it does resemble a living entity.
Due to this disparity, scientists often describe viruses as “organisms at the edge of life”.
Do viruses die? A virus cannot die outside the host since they are not alive. However, its capsid can degrade in the environment which ultimately makes the virus inactive. Inside our bodies, we have specialized T cells (white blood cells) that circulate looking for cells that are infected with viruses. Cytotoxic T cells kill cells that are infected with viruses. They recognize an antigenic peptide bonded to an infected cell.
Science has enabled humans to escape the perilous life of the cave and settle into modern human civilization. The comforts of modern human civilization offer us protection from predators like lions or wolves. Humans in modern cities no longer fear being devoured by lions. However, we fear no longer the giant predators but the invisible minuscule microbes. However, viruses are the most dangerous parasite that infects all living things. The elimination of all diseases is still a far-fetched dream for humanity.