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Cell shape is generally characteristic of a given bacterial species, but can vary depending on growth conditions. Some bacteria have complex life cycles involving the production of stalks and appendages (e.g. Caulobacter) and some produce elaborate structures bearing reproductive spores (e.g. Myxococcus, Streptomyces).
The endosteum (pl.: endostea) is a thin vascular membrane of connective tissue that lines the inner surface of the bony tissue that forms the medullary cavity of long bones. [ 1 ] [ 2 ] This endosteal surface is usually resorbed during long periods of malnutrition , resulting in less cortical thickness.
Bacteria function and reproduce as individual cells, but they can often aggregate in multicellular colonies. [54] Some species such as myxobacteria can aggregate into complex swarming structures, operating as multicellular groups as part of their life cycle , [ 55 ] or form clusters in bacterial colonies such as E.coli .
The composition of the outer membrane is distinct from that of the inner cytoplasmic cell membrane - among other things, the outer leaflet of the outer membrane of many gram-negative bacteria includes a complex lipopolysaccharide whose lipid portion acts as an endotoxin - and in some bacteria such as E. coli it is linked to the cell's ...
Transport proteins called porins are found in the outer membranes of mitochondria and chloroplasts and are also found in bacterial cell membranes. [67] [68] [69] A membrane lipid cardiolipin is exclusively found in the inner mitochondrial membrane and bacterial cell membranes. [70] Some mitochondria and some plastids contain single circular DNA ...
An endospore stain of the cell Bacillus subtilis showing endospores as green and the vegetative cell as red Phase-bright endospores of Paenibacillus alvei imaged with phase-contrast microscopy. An endospore is a dormant, tough, and non-reproductive structure produced by some bacteria in the phylum Bacillota.
The structure of the Bacterial Microcompartment shell. The first structure of a BMC shell, determined by X-ray crystallography and cryo-electron microscopy, [1] contains representatives of each of the shell protein types: BMC-P, BMC-H and BMC-T, in both its trimer (upper right) and dimer of trimer (lower right), forms.
The three-domain system adds a level of classification (the domains) "above" the kingdoms present in the previously used five- or six-kingdom systems.This classification system recognizes the fundamental divide between the two prokaryotic groups, insofar as Archaea appear to be more closely related to eukaryotes than they are to other prokaryotes – bacteria-like organisms with no cell nucleus.