How to Know the Difference between Viruses and Bacteria

viruses and bacteria


Are you studying for a biology exam? Are you lying in bed with the flu and curious about which microorganism has made you so ill? Although bacteria and viruses can make you very sick in similar ways, they are different organisms with many different characteristics. Knowing these differences can help you educate yourself about your medical treatments and better understand the complex biology that’s constantly going on inside you. You can tell the difference between bacteria and viruses not only by learning the basics but also by observing them through a microscope and discovering more about their structure and functions.

Learn the differences

Learn the basic differences.

There are key differences between bacteria and viruses in size, origin and effects on the body. Viruses are the smallest and simplest form of life. They are 10 to 100 times smaller than bacteria. Bacteria are intercellular organisms (meaning they live between cells), whereas viruses are intracellular organisms, meaning they invade and live in a host cell. Viruses alter the normal functioning of the genetic material in the host cell so that the virus itself is produced. Some bacteria are beneficial, but all viruses are harmful. Antibiotics cannot kill viruses, but they can kill bacteria, with the exception of most gram-negative bacteria.

You should know the differences in reproduction.

Viruses need a living host, such as a plant or animal, to reproduce. Most bacteria, on the other hand, can grow on inanimate surfaces. Bacteria have the necessary “machinery” (cell organelles) to grow and reproduce and usually reproduce asexually. Viruses, on the other hand, carry information – for example, DNA or RNA – in a protein and/or membrane envelope. They need the host cell’s machinery to reproduce. The “legs” of the virus attach to the surface of the cell and then the virus’ genetic material is injected into the cell. In other words, viruses don’t “live” properly. They’re basically information (DNA or RNA) floating around until it finds a suitable host.

Determine if the organism has a positive effect in the body.

Believe it or not, many small organisms live inside (but separate from) our bodies. When it comes to a sheer number of cells, most humans are made up of about 90% microbial life and only 10% human cells. Many bacteria live peacefully with our bodies. They even take on important tasks. They make vitamins, break down waste, and make oxygen. For example, much of the digestion is done by a type of bacteria called “gut flora.” These bacteria also help maintain pH balance in the body. However, it has not yet been shown that viruses perform functions that are good for humans. But there might be an exception to the rule soon. Researchers at Yale have developed a virus that could help fight brain tumors.

Determine if the organism meets the criteria for life.

While there is no precise, formal definition of what life is, all scientists agree that bacteria are undoubtedly alive. Viruses, on the other hand, seem to stand between life and death. They do “some” things that living organisms do, but don’t seem to live in any other way. Consider these things: Unless they have ingested another organism’s cell, viruses are dormant. No biological processes take place in them. They cannot break down nutrients, produce and excrete waste, or move on their own. They are essentially very similar to inanimate material. They can remain in this “dead” state for a very long time. When the virus comes in contact with a cell it can invade, it attaches itself and a protein enzyme dissolves part of the cell wall so it can inject its genetic material into the cell. At this point, when it invades the cell to make copies of itself, it exhibits an important characteristic of life: the ability to pass its genetic material to other generations and produce more organisms that are like itself.

You should know the bacteria and viruses that cause common diseases.

If you are sick and you know what it is, you can easily find out if you are dealing with a bacterium or virus by researching your condition. Below is a short list of common illnesses caused by bacteria or viruses. Bacteria: Pneumonia, E. coli, meningitis, strep throat, ear infections, food poisoning, wound infections, gonorrhea. Viruses: Hepatitis B, Rubella, SARS, Measles, Ebola, HPV, Herpes, Rabies, HIV, and COVID-19. Note that some illnesses, such as diarrhea or the common cold, can be caused by both organisms. If you don’t know exactly what condition you have, it’s harder to tell the difference between bacteria and a virus because the symptoms can be difficult to tell apart. Both bacteria and a virus can cause nausea, vomiting, high temperature, tiredness and general malaise. The best (and sometimes only) way to determine if you have a bacterial or viral infection is to see a doctor. They will do lab tests to determine the nature of your infection. You can tell if it’s a virus or bacteria by seeing if antibiotic treatment is effective. Antibiotics like penicillin will only help with a bacterial infection, not a viral infection. There is no known cure for a viral infection or disease.

Use this simple table to get an overview of the most basic differences between bacteria and viruses.

While there are more differences than those shown in the table, these are the main ones.”

Analyze microscopic properties

Search for a cell.

Structurally, bacteria are more complex than viruses. Bacteria are unicellular. That means each bacterium is made up of just a single cell (the human body is made up of trillions of cells.) Viruses, on the other hand, have no cells. They are made up of a protein structure called a capsid. Although this capsid contains the virus’ genetic material, it does not have the properties of a true cell; Viruses have no cell walls, no transport proteins, no cytoplasm, no organelles and so on. In other words, when you look at a cell through the microscope, you know you’re looking at a bacterium and not a virus.

Check the size of the organism.

A quick way to tell the difference between a bacterium and a virus is to compare their size. Bacteria are almost 100% larger than viruses. In fact, the largest viruses are only just as big as the very smallest bacteria. The average virus is 10 to 100 times smaller than an ordinary bacterium. More specifically, you can measure the organisms under the microscope. Bacteria range in size from one to several microns (1000+ nanometers) In contrast, most viruses are less than 200 nanometers in size.

Look for ribosomes (and no other organelles).

Bacteria do have cells, but not very complex ones. Bacteria do not have a nucleus and they lack all organelles except ribosomes. You can discover ribosomes by looking for small, simple organelles. In cell drawings, they are usually shown as dots or circles. Viruses, on the other hand, have no organelles and no ribosomes either. In fact, apart from the outer protein capsid, some simple protein enzymes, and genetic material in the form of DNA/RNA, there is not much else in the structure of most viruses.

Monitor the organism’s reproductive cycle.

Bacteria and viruses are not like most animals. They don’t need to have sex or share genetic information with other organisms of the same type in order to reproduce. But this does not mean that bacteria and viruses have the same reproductive strategies. Bacteria practice asexual reproduction. To reproduce, a bacterium replicates its own DNA, lengthens, and then divides into two daughter cells. Each daughter cell has one copy of the DNA, making them clones (exact copies). You can usually observe this process under a microscope. Each daughter cell grows and eventually divides into two more cells. Depending on the type of bacterium and the external conditions, bacteria can thus multiply very quickly. You can observe this process under a microscope and thus distinguish a bacterium from a virus. Viruses cannot reproduce on their own. Instead, they invade other cells and use their internal mechanisms to create new viruses. Eventually, so many viruses are made that the host cell ruptures and dies, releasing the new viruses in the process.


Karren Brandenburg

Karren Brandenburg is a travel and shopping expert. She has been quoted in Street Insider, Yahoo Finance, Reuters, ABC News, and MarketWatch. Karren has a total of 18 credit cards, using reward points to see the world on a budget.