Difference Between Bacteria vs Archaea
In the study of living things, it is impossible not to come across microorganisms as often as we do. This is because they serve quite some important roles in our health and way of living including fermentation of food, treatment of sewage, fuel production, and so on. An observer would easily think they are all the same, but they are not.
There are different types of microorganisms, and despite having similar functions, it is important to know their unique traits. On that note, we will be looking at the difference between bacteria and archaea, two common types of organisms. But before that, we will take a look at what they are and their specific features.
Definition of Bacteria
Bacteria is defined as a single-celled microscopic organism that can survive in almost any environment. They exist in the air, water, bodies of live and lifeless things, and so on. Aside from being diverse in nature, it is also fairly complex and comes in various domains of prokaryotic elements. They are also fairly complex in the sense that they possess a cellular structure that executes a range of vital functions.
The structure of a typical bacterium is a large single cell, basic internal structures, but no nucleus, which is why it is called prokaryotic. A nucleus is typically responsible for protein synthesis and cell division, and it houses the hereditary material of the organism.
Interestingly, this organism consists of a nucleoid, which stores the DNA. Since they do not have membrane-bound organelles, every process takes place within the cytoplasm.
These elements are known to exist in different sizes, shapes, and categories, and they are usually a few micrometers in length, which is why they are microscopic. The outer layer of the cell is a cytoplasmic membrane. Its function is to regulate what goes out of and into the organism. One difference between archaea and bacteria can be seen in their cell structures where the latter contains peptidoglycan, unlike the former.
Definition of Archaea
Archaea is defined as a group of single-celled organisms that lack a defined nucleus. They are also referred to as extremophiles and they have distinctive molecular traits that make them different from prokaryotic organisms.
Owing to the absence of a defined nucleus, the inherent materials of this element is stored in the plasmid – a tiny DNA molecule that can replicate on its own separately. With an anatomy and physiology that is quite different from others, this organism is considered to exhibit traits that are more similar to eukaryotes.
It has an outer cellular membrane (known as phospholipid) that regulates the transportation of material in and out of the cell and also helps to maintain the shape and chemical evenness of the cell.
Another variance in the archaea vs bacteria comparison can be seen in their method of reproduction. The two are known to reproduce asexually through binary fission, but the latter has the unique ability to create spores that can resist adverse environmental conditions.
Main Differences Between Bacteria vs Archaea
In this section, we will summarize the key differences between these two organisms in a tabular form. This will further enhance your understanding of how these two are different from one another.
| Basis of Comparison | Bacteria | Archaea |
| Definition | Diverse and fairly complex single-celled microbes that consist of a large domain of prokaryotic microorganisms | Single-celled organisms that consist of distinct molecular characteristics that differentiate them from other prokaryotic organisms |
| Metabolism | Photosynthesis, autotrophy, respiration, aerobic and anaerobic, and fermentation | Methanogenesis |
| Cell protection | Peptidoglycan / Lipopolysaccharide | Pseudopeptidoglycan |
| Environmental diversity | Very diverse | Not very diverse |
| Number of RNA | One | Three |
| Types | Gram-positive and gram-negative | Methanogens, Halophiles, Thermoacidophiles |
Difference Between Bacteria and Archaea: Conclusion
In conclusion, let us take a look at a few of the similarities you are most likely to come across when doing a bacteria vs archaea comparison. First, they both lack nucleus and membrane-bounded organelles, and they are almost the same size.
They also have a similar number of ribosomes and they can both be autotrophs or heterotrophs. They belong to the same category of prokaryotes, but they show variances in their metabolic pathways, heritable makeup, and general composition.
