What is the difference between Viruses and Bacteria?

For a more critical and precise grasp of the topic (what is the difference between Viruses and Bacteria), below is a tabulated list of the differences between viruses and bacteria.

What is the difference between Viruses and  Bacteria
Difference between Viruses and Bacteria (Image by Venngage Infographic Maker)

While it is true that viruses and bacteria are often (and sometimes mistakenly) associated with diseases, many find them to be seemingly indistinguishable. Despite being both microscopic in size, viruses and bacteria are very distinct from one another. Let us explore how viruses are different from bacteria at a microscopic level.

By strict definition, viruses are just a chain of genetic material (RNA) enclosed in a protein capsule. So because of that, viruses are not even considered to be cells or made up of them. Due to many reasons, viruses are often considered to be in the zone between living and non-living organisms.

Below we can discuss both viruses and bacteria in detail

What are viruses

A virus’s genetic material can be either DNA or RNA (but not both), encased in a capsid, a protein shell. Viruses can only have one of these types of genetic material.

Viruses are much smaller than bacteria. Bacteria can be seen by the naked eye, but viruses cannot. Viruses have a double-stranded DNA molecule(Most DNA viruses of animals contain double-stranded DNA. For example, Simian virus 40 (SV40) is a smallish, spherical virus that causes cancer in monkeys by inserting its DNA into the host chromosome) that is surrounded by a protein coat called a capsid.

Some viruses are enveloped, and others are not, so the viruses’ envelope is made up of fat and protein molecules. These protrusions will only connect to particular receptors on the host cell, and they are responsible for determining the kind of hosts or host cells that a virus will infect as well as the infectious capability of that virus.

Viruses can only be seen via a microscope because they are 10 and 100 times smaller than the tiniest bacterium.

Viruses are not considered living beings because they NEED to infect a host cell to carry out life-sustaining tasks or reproduce. However, certain viruses are capable of surviving on surfaces for extended periods. As a parasite, a virus must find a host cell to multiply and grow.

When a virus infects a host cell, it uses its genetic material to “hijack” the ribosomes in the host cell. These cellular structures are responsible for the production of proteins. Therefore, instead of the host cell making a protein that can be utilized by the cell, the virus makes its own proteins.

To produce new capsids and build new viruses, the virus also uses other components present within the host cell. These components include ATP (adenosine triphosphate), which is used as a source of energy, as well as amino acids and lipids.

When sufficient new viruses are produced, they will burst out of the cell in a process known as lysis, which will result in the death of the host cell. The process by which viruses make new copies of themselves is known as viral replication.

When new viruses are created, they can infect new host cells and new hosts after they have been produced. Most viruses cause disease and tend to attack specific parts of the body, like the liver, lungs, or blood.

Herpes zoster, HIV, influenza, the common cold, and the virus that causes rabies are all common viruses. In addition, viruses are a potential source of pneumonia and sinusitis. Another virus is the newly discovered coronavirus SARs-CoV-2, which is responsible for COVID-19.

Viruses can infect humans, animals, and plants; however, the vast majority of plant viruses are transmitted by insects or other creatures that feed on the cell walls of plants.

Vaccination is the most effective method for preventing viral infections; nevertheless, antivirals have been designed to treat certain viral diseases, such as HIV or Hepatitis C. Vaccination is the most effective method for preventing viral infections. Antibiotics are not effective against viral infections and cannot treat them.

What are Bacteria?

On the other hand, bacteria (singular–bacterium) are single-celled organisms that are characterized by the pieces of their genetic material dispersed in cellular membrane fluid surrounded by a rigid cell wall. Superficially, bacteria may seem to be mere simple organisms; however, they can be considered to be very sophisticated yet very adaptable. Unlike viruses, they are capable of surviving and replicating themselves independently, traits that differentiate them from viruses.

  • Relative to viruses, bacteria can be ten to a hundred times larger. Aside from that, they reproduce through binary fission, where they simply divide as they replicate their genetic material.
  • However, it should be noted that there are some species of bacteria (i.e., Chlamydia and Rickettsia) that like viruses, are incapable of reproducing outside a host cell.
  • Most of the commonly known bacteria are pathogenic ones. The good thing is, that some bacteria can be eliminated by interfering with their internal biological and physiological processes (through the use of antibiotics).


In conclusion, viruses and bacteria differ from each other mainly because of properties such as living attributes, mode of reproduction, mode of infection, as well as their killing agents. Nevertheless, as more and more research is becoming geared toward microorganisms, it is just becoming more evident that there remains a lot to be discovered.


  • https://venngage.com/
  • https://en.wikipedia.org/wiki/Virus#:~:text=In%20general%2C%20viruses%20are%20much,between%2020%20and%20300%20nanometres.
  • https://en.wikipedia.org/wiki/Bacteria

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