Table 1: Differences and Similarities between Bacteria and Archaea
| Structural Characteristic | Bacteria | Archaea |
| Cell type | Prokaryotic | Prokaryotic |
| Cell morphology | Variable | Variable |
| Cell wall | Contains peptidoglycan | Does not contain peptidoglycan |
| Cell membrane type | Lipid bilayer | Lipid bilayer or lipid monolayer |
What are the differences and similarities between bacteria and archaea?
Similarities
- Both the types have the almost same size which varies from 0.5 – 4 micron and so are said to be smallest cell in existence.
- They both lack membrane-bounded organelles and nucleus.
- Archaea and bacteria lack multicellularity, and the chromosome is single and circular.
When comparing members of archaea with bacteria?
These two microorganisms belong to the kingdom of Monera. Understanding these two terms tend to be quite complicated. The core difference between archaea and bacteria is that archaea refer to a single-celled organism with distinctive cell properties while bacteria refer to a single-celled organism that lives in a diverse environment.
What are the differences between archea and bacteria?
Some of their key differences include:
- The cell walls and membrane lipids (fatty acids) of bacteria and Archaea are made up of different chemicals;
- Many types of bacteria can perform photosynthesis (generating oxygen from sunlight), while Archaea cannot;
- Archaeal and bacterial flagella are constructed differently;
- Archaea reproduce by fission while some bacteria produce spores;
Which characteristic is unique to archaebacteria?
- Archaebacteria are obligate anaerobes and they survive only in oxygen-free environments.
- They are known as extremophiles, as they are able to live in a variety of environment. ...
- The size of archaebacteria ranges from one-tenth of a micrometer to more than 15 micrometers. ...
- Like all prokaryotes, archaebacteria don’t possess the membrane-bound organelles. ...
Do bacteria and archaea have the same structure?
The general cell structure of archaea and bacteria are the same but composition and organization of some structures differ in archaea. Similar to bacteria, archaea do not have interior membranes but both have a cell wall and use flagella to swim.
What structural difference is between archaea and bacteria?
Bacterial cell walls are composed of peptidoglycan, a complex of protein and sugars, while archaeal cell walls are composed of polysaccharides (sugars). The composition of their cell walls also differs from the eukaryotic cell walls found in plants (cellulose) or fungi and insects (chitin).
What structures do bacteria and archaea have in common?
Both archaea and bacteria have flagella, thread-like structures that allow organisms to move by propelling them through their environment.
What are two major differences between bacteria and archaea?
A possible answer is: Bacteria contain peptidoglycan in the cell wall; archaea do not. The cell membrane in bacteria is a lipid bilayer; in archaea, it can be a lipid bilayer or a monolayer. Bacteria contain fatty acids on the cell membrane, whereas archaea contain phytanyl.
What Three features distinguish archaea from bacterial cells?
Which three of the following characteristics distinguish bacteria from archaea? capsules and slime layers found on most cells. type of lipid molecules found in plasma membranes. presence of peptidoglycan in cell walls.
What is the difference between archaea and bacteria quizlet?
Archaea have more complex RNA polymerases than Bacteria, similar to Eucarya. Unlike bacteria, archaea cell walls do not contain peptidoglycan. Archaea have different membrane lipid bonding from bacteria and eukarya. There are genetic differences.
In which three ways are bacteria and archaea similar?
What do bacteria and archaea have in common?Both bacteria and archaea are prokaryotes. ... Both bacteria and archaea are single cellular organisms. ... Both bacteria and archaea like to form a community. ... Bacteria and archaea have similar sizes and shapes. ... Both bacteria and archaea can be found everywhere on Earth.More items...
How are archaea most similar to bacteria?
They both are single-celled, microscopic organisms that can come in a variety of shapes (Figure below). Both archaea and bacteria have a single circular chromosome of DNA and lack membrane-bound organelles. Like bacteria, archaea can have flagella to assist with movement.
What are the similarities between archaea and eubacteria?
The similarities are that archaea and eubacteria are prokaryotes — single-celled organisms that do not have a nucleus or organelles.
Where can archaea live?
Archaea can survive in extreme and harsh environments like hot springs, salt lakes, marshlands, oceans, gut of ruminants and humans. Eubacteria are ubiquitous and are found in soil, hot springs, radioactive waste water, Earth's crust, organic matter, bodies of plants and animals etc.
How do archaea reproduce?
Reproduction and growth. Archaea reproduce asexually by the process of binary fission, budding and fragmentation. Eubacteria reproduce asexually through binary fission, budding, fragmentation, but eubacteria have the unique ability to form spores to remain dormant over years, a trait that is not exhibited by Archaea.
What were the groups of prokaryotic organisms called?
So they divided prokaryotic life into what they called archaeabacteria and eubacteria. However, they later concluded that "archaeabacteria" were sufficiently different as to not be bacteria at all. So the groups were renamed to archaea and bacteria . The tree of life showing classification of all living organisms.
What are the five kingdoms of living things?
So by the 1970s, the classification system evolved to what was known as Five Kingdoms — prokaryotes (bacteria) and eukaryotes (plants, animals, fungi, protists).
What is the definition of a prokaryotic microbe?
These microbes are prokaryotes, meaning that they have no cell nucleus or any other membrane-bound organelles in their cells. Bacteria constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Cell wall.
What type of pili is Archaea?
Archaea flagella evolved from bacterial type IV pili while bacterial flagella evolved from type III secretion system. Bacterial flagellum is like a stalk which is hollow and is assembled by subunits that are free to move up the central pore adding on to tip of flagella while in archaea flagella subunits are added on to the base.
Definition: What are prokaryotes
Prokaryotes (pro-KAR-ee-ot-es) are unicellular organisms that don’t have a membrane-bound nucleus and other organelles. Both bacteria and archaea are prokaryotes. Learn what are the differences between Eukaryotes and Prokaryotes below.
Definition: What are bacteria?
Bacteria (singular: Bacterium) are single-celled microbes with cell walls. Bacteria are found almost everywhere on Earth. Some live in or on other organisms, including plants and animals. The human body is full of bacteria; many of these bacterial cells are found living in the gut and are important for our health.
Definition: What are archaea?
Archaea are another group of single-celled microbes. They were originally classified as ancient bacteria but later received their own Domain.
What do bacteria and archaea have in common?
Bacterial and archaeal cells do not have a membrane-bound nucleus. Their genetic materials (DNA) are within the cytoplasm. They also lack other membrane-bound cell organelles, including mitochondria, chloroplasts, endoplasmic reticulum (ER), and Golgi apparatus.
Archaea are closer to eukarya than bacteria
Surprisingly, scientists found that compared to bacteria, archaea in many aspects are closer to eukaryotic cells! You can see the comparison in the table below:
Summary – bacteria vs. archaea
1. Bacteria and archaea are two groups of microbes that belong to Domain Bacteria and Doman Archaea, respectively. 2. However, archaea and bacteria share many similarities as well. They are prokaryotic, single-celled microorganisms with cell walls. Both form biofilms and live everywhere on Earth by adapting to use diverse sources of energy. 3.
Q&A: Some frequently asked questions are quickly answered here
1. Cell wall – Archaeal cell walls don’t contain peptidoglycan. 2. Cell membrane – Archaea have unique cell membrane with branched lipid molecules. 3. rRNA sequence – Scientists use ribosomal RNA sequences to define the Domains of Bacteria and Archaea. 4.
What are the characteristics of archaea?
They lack cell nuclei and therefore come under the category of prokaryotes. These organisms inhabit extreme environments, like saline water, deep-sea vents, hot springs, and also below petroleum deposits. Archaea obtain energy from various sources like carbon dioxide, acetate, ammonia, sulfur, and even sunlight.
Where are archaea found?
Archaea are extremophiles, found in extreme environments like the deep sea, hot springs and salt brine, etc.
How many species of methanogens are there?
More than 50 species of methanogens are known so far.
How do archaea get energy?
Archaea obtain energy from various sources like carbon dioxide, acetate, ammonia, sulfur, and even sunlight. The group of Archaea using sunlight as the source of energy are known as phototrophs. Oxygen-generated photosynthesis is not performed by these organisms. Another form of Archaea that derives energy from ammonia and sulfur includes anaerobic methane oxidizers, nitrifiers, and methanogens.
What is the smallest organism in the world?
Bacteria are single cell prokaryotes that form domains of organisms depending on shape, size, habitat, and structure. They are membrane and less cell organelles, hence they are simple in structure and functions. They are the smallest entities in the world, thus microscopic.
Why are bacteria beneficial?
Some bacteria are beneficial for antibiotic production, biochemical cycles, and industrial use. But some pathogenic organisms can lead to diseases.
Which form of Archaea derives energy from ammonia and sulfur?
Another form of Archaea that derives energy from ammonia and sulfur includes anaerobic methane oxidizers, nitrifiers, and methanogens.
How do archaea reproduce?
Archaea and Bacteria reproduce through fission, a process where an individual cell reproduces its single chromosome and splits in two. Eukaryotes reproduce through mitosis, which includes additional steps for replicating and correctly dividing multiple chromosomes between two daughter cells.
What are the cell walls of bacteria?
Bacterial cell walls are composed of peptidoglycan, a complex of protein and sugars, while archaeal cell walls are composed of polysaccharides (sugars). The composition of their cell walls also differs from the eukaryotic cell walls found in plants (cellulose) or fungi and insects (chitin).
What was the first living organism?
The fossil record indicates that the first living organisms were prokaryotes (Bacteria and Archaea), and eukaryotes arose a billion years later. Study Tip: It is suggested that you create a chart to compare and contrast the three domains of life as you read. The information below was adapted from OpenStax Biology 22.2.
How do prokaryotes live?
Prokaryotes have been and are able to live in every environment by using whatever energy and carbon sources are available. Prokaryotes fill many niches on Earth, including being involved in nutrient cycles such as nitrogen and carbon cycles, decomposing dead organisms, and thriving inside living organisms, including humans. The very broad range of environments that prokaryotes occupy is possible because they have diverse metabolic processes. Phototrophs (or phototrophic organisms) obtain their energy from sunlight. Chemotrophs (or chemosynthetic organisms) obtain their energy from chemical compounds.
Which organisms have circular DNA?
Archaea and Bacteria generally have a single circular chromosome– a piece of circular, double-stranded DNA located in an area of the cell called the nucleoid. In contrast, many eukaryotes have multiple, linear chromosomes.
What is the importance of prokaryotes?
Describe the importance of prokaryotes (bacteria and archaea) with respect to human health and environmental processes.
Is Archaea a multicellular organism?
Archaea and Bacteria share a number of features, but are also distinct domains of life: Both Archaea and Bacteria are unicellular organisms. In this way they are different from eukaryotes, which include both unicellular and multicellular organisms.
What is the difference between bacteria and archaea?
Difference Between Archaea and Bacteria. Despite being in the same category of prokaryotes, archaea and bacteria show variances in their genetic makeup , as the metabolic pathways , and other enzymes , genes possessed by the archaea closely resembles eukaryotes rather bacteria. Simple, microscopic, ambiguous microorganisms mark their presence ...
What are the similarities between Archaea and Bacteria?
They both lack membrane-bounded organelles and nucleus. Archaea and bacteria lack multicellularity, and the chromosome is single and circular.
How do archaea reproduce?
Archaea reproduce asexually by binary fission, fragmentation, or by the budding process, on the other hand, bacteria can produce spores which allow them to live in unfavourable condition and they divide sexually as well as asexually.
How do archaea divide?
As discussed earlier, they divide asexually by budding, fragmentation or binary fission process. Archaea consist of the single-circular chromosome in the form of the plasmid. The outer cellular membrane act as the barrier to the cell and its outer environment and is made up of phospholipid ( pseudo peptidoglycans).
What kingdom is Archaea in?
Archaea and bacteria are the representatives of the prokaryotes and belong to the kingdom Monera. Archaea are considered to be the most primitive or ancient forms of life and denote the close relations to the first cells, which is deemed to arise about many years ago on earth.
What is the cell wall of Archaea made of?
Unlike to the bacteria, the cell wall of archaea is made up of pseudo peptidoglycans. The lipid membrane is ether linked, with the branching of aliphatic acids.
How old are bacteria?
The evolving history of these cells is considered to be old as more than 3.5 billion years ago. Archaea and bacteria are the representatives of the prokaryotes and belong to the kingdom Monera.
What are the major groups of archaea and bacteria?
Major bacterial phyla include the Proteobacteria, the Chlamydias, the Spirochaetes, the photosynthetic Cyanobacteria, and the Gram-positive bacteria.
How many phyla are there in Archaea?
Figure 6: Archaeal phyla. Archaea are separated into four phyla: the Korarchaeota, Euryarchaeota, Crenarchaeota, and Nanoarchaeota. (credit “Halobacterium”: modification of work by NASA; credit “Nanoarchaeotum equitans”: modification of work by Karl O. Stetter; credit “Korarchaeota”: modification of work by Office of Science of the U.S. Dept. of Energy; scale-bar data from Matt Russell)
What are the two groups of bacteria?
Bacteria are divided into two major groups: Gram positive and Gram negative, based on their reaction to Gram staining. Note that all Gram-positive bacteria belong to one phylum; bacteria in the other phyla (Proteobacteria, Chlamydias, Spirochetes, Cyanobacteria, and others) are Gram-negative. The Gram staining method is named after its inventor, Danish scientist Hans Christian Gram (1853–1938). The different bacterial responses to the staining procedure are ultimately due to cell wall structure. Gram-positive organisms typically lack the outer membrane found in Gram-negative organisms (Figure 8). Up to 90 percent of the cell-wall in Gram-positive bacteria is composed of peptidoglycan, and most of the rest is composed of acidic substances called teichoic acids. Teichoic acids may be covalently linked to lipids in the plasma membrane to form lipoteichoic acids. Lipoteichoic acids anchor the cell wall to the cell membrane. Gram-negative bacteria have a relatively thin cell wall composed of a few layers of peptidoglycan (only 10 percent of the total cell wall), surrounded by an outer envelope containing lipopolysaccharides (LPS) and lipoproteins. This outer envelope is sometimes referred to as a second lipid bilayer. The chemistry of this outer envelope is very different, however, from that of the typical lipid bilayer that forms plasma membranes.
How do prokaryotes reproduce?
Reproduction in prokaryotes is asexual and usually takes place by binary fission. (Recall that the DNA of a prokaryote is a single, circular chromosome.) Prokaryotes do not undergo mitosis; instead, the chromosome is replicated and the two resulting copies separate from one another, due to the growth of the cell. The prokaryote, now enlarged, is pinched inward at its equator and the two resulting cells, which are clones, separate. Binary fission does not provide an opportunity for genetic recombination or genetic diversity, but prokaryotes can share genes by three other mechanisms.
What is the difference between prokaryotic and eukaryotic cells?
There are many differences between prokaryotic and eukaryotic cells. The name “prokaryote” suggest s that prokaryotes are defined by exclusion—they are not eukaryotes, or organisms whose cells contain a nucleus and other internal membrane-bound organelles. However, all cells have four common structures: the plasma membrane, ...
What is the membrane of a prokaryotic cell?
The prokaryotic plasma membrane is a thin lipid bilayer (6 to 8 nanometers) that completely surrounds the cell and separates the inside from the outside. Its selectively permeable nature keeps ions, proteins, and other molecules within the cell and prevents them from diffusing into the extracellular environment, while other molecules may move through the membrane. Recall that the general structure of a cell membrane is a phospholipid bilayer composed of two layers of lipid molecules. In archaeal cell membranes, isoprene (phytanyl) chains linked to glycerol replace the fatty acids linked to glycerol in bacterial membranes. Some archaeal membranes are lipid monolayers instead of bilayers (Figure 7).
How is DNA transferred from one prokaryote to another?
In conjugation, DNA is transferred from one prokaryote to another by means of a pilus, which brings the organisms into contact with one another, and provides a channel for transfer of DNA. The DNA transferred can be in the form of a plasmid or as a composite molecule, containing both plasmid and chromosomal DNA.
History of Phylogenetic Classification
Size and Shape
- Both archaea and eubacteria are similar in shape and size. They are both found occurring as rods, cocci, spirals, plates, or coiled.
Difference in Cell Structure
- The general cell structure of archaea and bacteria are the same but composition and organization of some structures differ in archaea. Similar to bacteria, archaea do not have interior membranes but both have a cell wall and use flagellato swim. Archaea differ in the fact that their cell wall does not contain peptidoglycan and cell membrane uses et...
Flagella
- Archaea flagella evolved from bacterial type IV pili while bacterial flagella evolved from type III secretion system. Bacterial flagellum is like a stalk which is hollow and is assembled by subunits that are free to move up the central pore adding on to tip of flagella while in archaea flagella subunits are added on to the base.
Reproduction and Growth
- Archaea reproduce asexually by the process of binary fission, budding and fragmentation. Eubacteria reproduce asexually through binary fission, budding, fragmentation, but eubacteria have the unique ability to form spores to remain dormant over years, a trait that is not exhibited by Archaea. Bacteriagrowth follows in three phases, the lag phase when cells adapt to new environ…
Habitat
- Archaea can survive in extreme and harsh environments like hot springs, salt lakes, marshlands, oceans, gut of ruminants and humans. Eubacteriaare ubiquitous and are found in soil, hot springs, radioactive waste water, Earth's crust, organic matter, bodies of plants and animals etc.
References
- Eubacteria (definition)
- Bacteria - Wikipedia
- Archaea - Wikipedia
- Introduction to Archaea
Learning Objectives
- Differentiate between bacteria, archaea, and eukarya.
- Draw the phylogenetic relationships between bacteria, archaea, and eukarya.
- Identify ways that archaea and bacteria get energy and carbon.
- Explain the fossil, chemical, and genetic evidence for key events for evolution of the three domains of life (bacteria, archaea, eukarya)
Three Domains of Life on Earth
- DNA sequence comparisons and structural and biochemical comparisons consistently categorize all living organisms into 3 primary domains: Bacteria, Archaea, and Eukarya (also calledEukaryotes; these terms can be used interchangeably). Both Bacteria and Archaea are prokaryotes, single-celled microorganisms with no nuclei, and Eukarya includes us and ...
Metabolic Diversity of Prokaryotes
- The information below was adapted from OpenStax Biology 22.3 Prokaryotes have been and are able to live in every environment by using whatever energy and carbon sources are available. Prokaryotes fill many niches on Earth, including being involved in nutrient cycles such as nitrogen and carbon cycles, decomposing dead organisms, and thriving inside living organisms, includin…
Key Events and Evidence in The Evolution of The Three Domains of Life on Earth
- Early life on Earth: The Earth is approximately 4.6 billion years old based on radiometric dating. While it is formally possible that life arose during the Hadean eon, conditions may not have been stable enough on the planet to sustain life because large numbers of asteroids were thought to have collided with the planet during the end of the Hadean and beginning of the Archean eons. E…
Placing Key Events on The Geologic Time Scale
- How do each of these events map onto geologic time? Most of them are not “instantaneous” events, and so they span multiple time periods as follows: 1. Hadean eon (4.6-4 BYA): No life present on Earth 2. Archean eon (4 to 2.5 BYA) 2.1. Origin of life (prokaryotic, anaerobic), 2.8-2.6 BYA 2.2. First cyanobacteria, capable of producing oxygen through photosynthesis, ~2.5 BYA 3. …
Links to Human Health and Environmental Processes
- The information below was adapted from OpenStax Biology 22.4 Some prokaryotic species can harm human health as pathogens: Devastating pathogen-borne diseases and plagues, both viral and bacterial in nature, have affected humans since the beginning of human history, but at the time, their cause was not understood. Over time, people came to realize that staying apart from …