This characteristic forms the basis of classification of Eubacteria. They are mainly classified as either Spherical Eubacteria also known as the cocci, spiral or helically-shaped Eubacteria (Spirilla), or rod-shaped Eubacteria (bacilli) . Morphology; Eubacteria are unicellular Prokaryotic cells with a cell wall surrounded by carbohydrates to protect the bacteria from injury. The whole structure of a Eubacteria consist of a cell wall, a capsule or a plasma membrane, ribosomes, nucleoid and cytoplasm.
Cell walls of Eubacteria is composed of peptidoglycan and always cover the cell membrane. In most Eubacteria, this cell wall is covered by another layer called the outer membrane. Apart from the cell wall and the outer membrane, some Eubacteria also have the capsule. Eubacterial capsule serve to protect the cell from environmental damage, like the host’s immune system bactericidal and bacteriostatic cells and activities for example phagocytosis.
It also protects the cell from dehydration. These capsules are either composed of protein or carbohydrate, and can be tightly or loosely bound or not present at all in a bacterial cell. This depends on the type of the bacteria. Apart form protection, cell attachment is also another function. These organisms have a very simple structure general to all that consist of prokaryotic chromosomes with fewer related proteins. Within the chromosomes are circular DNA structures called plasmids.
Since Eubacteria are prokaryotes, they do not have the nuclear membrane; their plasmids therefore are located just in the cytoplasm in structures called nucleoids. The remaining space of the cytoplasm is occupied by the ribosomes . Eubacteria do not have the cell organelles, instead, they have specialized internal membranes for example with membranes that carry out photosynthesis. These cyanobacteria membranes contain chemicals and chlorophyll required for photosynthesis. Locomotion; A great number of these organisms are capable of moving from one place to the other.
Movement of Eubacteria is mostly through flagella for the organisms with flagella and whip-like projections for the ones with this kind of structures. There is a difference between the prokaryotic flagella and the eukaryotic flagella. Prokaryotic flagella is made up of flagellin, (the protein subunits) move in a spiral motion and are attached to the plasma membrane, while eukaryotic flagella are within the plasma membrane, made up of several tubulin micro tubules and move in two directions only, back and forth.
It is only the species ‘spirochetes’ with the flagella that resemble the eukaryotic flagella . The bacterial flagellum; This is a structure that looks like the flagella of the eukaruote but is anchored to a rotor like structure in the bacteria. it contains flagellin just as noted before. This rotor extends into the cytoplasm and causes the flagella to move in a spiral manner. All these is made possible by the sodium or hydrogen ions from the outside of the cell flowing along the concentration gradient.