What are the main differences between archaea and bacteria

1. The growth environment is different. Archaea (archaeokaryotic cells) live in extreme environments such as hot springs, anoxic lake bottoms, and salt water lakes. Bacteria are more tolerant to low temperatures, and most bacteria can be stored for many years in liquid air (-190) or liquid oxygen (-252).

2. The nature is different. Archaeaa have unique biochemical properties, such as membrane lipids are connected by ether bonds instead of ester bonds, and their nutritional patterns are also different from those of conventional organisms, and the shapes of bacteria are quite diverse, mainly globular, rod-shaped, and spiral-shaped.

3. Morphologically, archaea have cells with flat right-angle geometry, which has never been seen in bacteria.

4. On introns, many archaea have introns, but not in bacteria.

5. In terms of metabolic diversity, archaea are simple and bacteria are diverse.

6. In terms of molecular plasticity, archaea have more changes than bacteria.

7. In terms of evolutionary rate, archaea are slower than bacteria and retain more primitive characteristics.

Similarities: they are all prokaryotes, their DNA is circular, and they are globular in morphology, rod-shaped, and so on.

Differences. 1 The cell wall of bacteria contains peptidoglycan, while archaea do not have this compound, 2 The structure of the trRNA molecule of archaea is different from that of bacteria, and many of the characteristics of the transferred RNA of archaea are more similar to those of eukaryotes.

3 Many of the characteristics of the ribonucleosomes of archaea are also more similar to those of higher eukaryotes, for example: the ribonucleosomes of bacteria are sensitive to certain chemical inhibitors, while archaea and eukaryotes are indifferent to these inhibitors.

Archaea do not have peptidoglycan and contain ether bonds in the cell membrane.

The cell wall cell membrane is also different, archaea are 1-3 glycosidic bonds for bacteria and 1-4 glycosidic bonds, cell membrane archaea are single membranes with double membranes or a mixture of single and double membranes, and bacteria only have the so-called double membrane structure, which is the phosphate bilayer.

1. Differences in the cell wall.

The cell wall of archaea is composed of polysaccharides, glycoproteins, and proteins, and the most common type of cell wall is the crystalline surface layer.

The cell wall of eubacterial G+ mainly contains peptidoglycan, and some contain teichoic acid; g- Contains sparse peptidoglycan and lipopolysaccharides, proteins, and periplasms.

2. Differences in cell membranes.

Archaea: The hydrophobic tail of phospholipids is composed of isoprene repeating units, the hydrophilic head (glycerol) and the hydrophobic tail are connected by ether bonds, and the side chains of the cell membrane are composed of different compounds.

The fatty acids of bacteria and eukaryotes do not have these lateral branches.

Archaea (also known as archaea, archaea) are a class of prokaryotic microorganisms that survive in extreme environments (such as hypoxia, high temperature, etc.) and are similar in morphology to bacteria. The concept of archaea was proposed in 1977 by Carl Voss and George Fox, who discovered that it was different from other prokaryotes while studying the phylogenetic tree of 16S rRNA. These two groups of prokaryotes were originally classified as archaebacteria and eubacteria.

Woese thought they were two fundamentally different organisms and renamed them archaea and bacteria. The Berger Handbook of Systematic Bacteriology, published in 2001, divides prokaryotes into archaeal and bacterial domains. Together, archaea, bacteria, and eukaryotes (eukarya) make up the three-domain system of organisms.

Although archaea are similar to bacteria, archaeal chromosomal DNA is closed in a loop, and genes are organized into operons; anuclear membrane and endomembrane system; The cell morphology is similar, and they also have globular, rod-shaped, spiral-shaped, irregular shape, polymorphism, etc., but they have essential differences.

1. Different environmental adaptability: archaea (also known as archaea or archaea) are a very special class of bacteria, which mostly live in extreme ecological environments. For example, in lake water with high salinity, extremely hot, extremely acidic and absolutely anaerobic environment, some survive in extremely cold environments, and bacteria mostly grow in relatively mild environments similar to humans.

2. Different ways of gene-protein transcription and translation: archaea are obviously different from bacteria in the two central processes of molecular biology, gene transcription and translation, but are very close to eukaryotes. For example, the translation of archaeal proteins uses eukaryotic initiation and elongation factors, methionine initiates protein synthesis, ribosomes are insensitive to chloramphenicol, RNA polymerases are similar to eukaryotic cells, DNA has introns and binds histones, and protein translation requires Tata box-binding proteins and TFIIBs in eukaryotes.

3. Different cell structure: archaea only have a cell membrane and lack of peptidoglycan cell wall. The cell walls of most archaea do not contain diaminopinheptic acid (D amino acid) and muramic acid, and are not affected by lysozyme and lactam antibiotics such as penicillin.

Moreover, the lipids in the cell membranes of the vast majority of bacteria and eukaryotes are mainly composed of glycerides, while the membrane lipids of archaea are composed of phospholipids and glycolipid derivatives of non-saponifiable glyceride dieethers. These differences may be due to adaptation to extreme environments such as ultra-high temperatures. There are two types of archaeal cell membranes:

Double-layer and single-layer films. The composition and formation process of archaeal flagella are also different from those of bacteria.

Answer] Sensitive: The main differences are: the 16srRNA gene of archaea lacks the imprinted sequence as a bacterial signature; There is absolutely no muramic acid in the cell wall foci; membrane lipids with ether bond branched chains; The T or T C arm of the trRNA of the disruptor branch does not have thymine; special RNA polymerases; The composition and shape of ribosomes are also different.

1. The scope of life is different.

Fungi live in a wide range of areas, they are present in the soil, in the water, in the air, and even on our bodies;

Archaea often live in extreme environments such as hot spring water, anoxic lake bottoms, and salt water lakes.

2. Different metabolism.

The metabolism of fungi is characterized by diversity;

The metabolism of archaea is simple.

3. The structure and composition of the membrane are different.

The membrane structure of fungi is mainly composed of phospholipids and proteins, and also contains a small amount of sugars.

Archaeacal membranes contain ethers rather than esters, in which glycerol is linked to the long-chain hydrocarbon isoprene by ether bonds, rather than to fatty acids by ester bonds.

4. Different breathing patterns.

In addition to aerobic and facultative anaerobic, fungi also have obligate anaerobic of yeasts;

The main type of respiration of archaea is strictly anaerobic.

In terms of cell structure and metabolism, archaea are close to other prokaryotes in many ways. However, in terms of gene transcription, the two central processes of molecular biology, they do not obviously show the characteristics of bacteria, but are very close to eukaryotes. For example, the translation of archaea uses eukaryotic priming and elongation factors, and the translation process requires the Tata box-binding protein and TFIIB in eukaryotes.

Archaeaa also have some other characteristics. Unlike most bacteria, they have only one layer of cell membrane and lack a peptidoglycan cell wall. Moreover, the lipids in the cell membranes of the vast majority of bacteria and eukaryotes are mainly composed of glycerides, while the membrane lipids of archaea are composed of glyceryl ethers.

These differences may be due to adaptation to ultra-high temperature environments. The composition and formation process of archaeal flagella are also different from those of bacteria.

The phylogenetic tree based on RNA sequences shows three distinct clades: bacteria, archaea, and eukaryotes