fermentacja: Bacteria

Evidence: 70 • authority: 72

The cell is the basic structural and functional unit of all forms of life or organisms. The term comes from the Latin word cellula meaning 'small room'. A biological cell basically consists of a semipermeable cell membrane enclosing cytoplasm that contains genetic material. Most cells are only visible under a microscope. Except for highly-differentiated cell types (examples include red blood cells and gametes) most cells are capable of replication, and protein synthesis. Some types of cell are motile. Cells emerged on Earth about four billion years ago. All organisms are grouped into prokaryotes and eukaryotes. Prokaryotes are single-celled and include archaea and bacteria. Eukaryotes can b…

Evidence: 64 • authority: 88

Structural and Functional stability and asymmetry among organelles and Organs Appear Regulated by The Specific Genes in Stem cells. I. Emanation of Chromatin From Chromosomes is Also an Inherent Genomic Mechanism Among Eukaryotes. The release of chromatin dots from various chromosomes from within the cells has been observed several times over five decades; sometimes even the detaching fibril has been clearly observed. Mitotic and meiotic cells observed from plants, animals and human lymphocyte cultured cells have confirmed our consistent observations. Earlier we had named these chromatin emanations as marker dots. Plants of a few species of Ophioglossum L, Isoetes L and some ferns in natura…

Evidence: 57 • authority: 72

The eukaryotes () are cellular organisms of the domain Eukaryota or Eukarya, which have a distinct cell nucleus (formed by a nuclear membrane), membrane-bound organelles and organization supported by a cytoskeleton. Extant eukaryotes are traditionally grouped into four kingdoms: animals, plants, fungi and protists. "Protists" are a basal paraphyletic group that includes all algae, amoebae, flagellates and ciliates; however, this is now considered a wastebasket taxon and has been replaced with newer classifications that better represent the phylogeny of these organisms. As part of the prevailing three-domain system, eukaryotes constitute a major group of organisms alongside the two domains o…

Evidence: 57 • authority: 72

Marine prokaryotes are marine bacteria and marine archaea. They are defined by their habitat as prokaryotes that live in marine environments, that is, in the saltwater of seas or oceans or the brackish water of coastal estuaries. All cellular life forms can be divided into prokaryotes and eukaryotes. Eukaryotes are organisms whose cells have a nucleus enclosed within membranes, whereas prokaryotes are the organisms that do not have a nucleus enclosed within a membrane. The three-domain system of classifying life adds another division: the prokaryotes are divided into two domains of life, the microscopic bacteria and the microscopic archaea, while everything else, the eukaryotes, become the…

Evidence: 51 • authority: 72

Bacteria, despite apparent simplicity, have highly organized and efficient cell structures, which allow them to fill many ecological niches. While resembling other prokaryotes, many features of bacterial cells are unique to bacteria, and not found among archaea or eukaryotes. Bacterial cells have fewer components than eukarotic cells, and are often easier to manipulate experimentally relative to eukaryotes. Therefore, many biochemical principles were first characterized in bacteria before these principles were subsequently applied to other organisms.

Evidence: 51 • authority: 72

Cell division is the process by which a parent cell divides into two daughter cells. Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukaryotes, there are two distinct types of cell division: a vegetative division (mitosis), producing daughter cells genetically identical to the parent cell, and a cell division that produces haploid gametes for sexual reproduction (meiosis), reducing the number of chromosomes from two of each type in the diploid parent cell to one of each type in the daughter cells. Mitosis is a part of the cell cycle, in which, replicated chromosomes are separated into two new nuclei. C…

Evidence: 44 • authority: 88

Borrelia burgdorferi Outer Membrane Vesicles Contain Antigenic Proteins, but Do Not Induce Cell Death in Human Cells. Like many bacterial species, Borrelia burgdorferi, the pleomorphic bacterium that causes Lyme borreliosis, produces outer membrane vesicles (OMVs). Borrelial OMVs (BbOMVs) have been identified as containing virulence factors, such as outer surface proteins (Osps) A, B, and C, as well as DNA. However, the pathogenicity of BbOMVs in disease development is still unclear. In this study, we characterized purified BbOMVs by analyzing their size and immunolabeling for known antigenic markers: OspA, OspC, p39, and peptidoglycan. In addition, BbOMVs were cocultured with human non-imm…

Evidence: 44 • authority: 72

A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. Since the first discovery of a virus, the tobacco mosaic virus, in the 1890s, more than 16,000 of the millions of virus species have been described in detail. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in th…

Evidence: 38 • authority: 88

The acid phosphatase positive organelles of the <i>Giardia lamblia</i> trophozoite contain a membrane bound cathepsin C activity. Abstract We found a dipeptidyl aminopeptidase activity in the parasitic protozoan Giardia lamblia with properties similar to the lysosomal cathepsin C of rat‐liver lysosomes. Subcellular fractionation of this parasite indicated that the cathepsin C activity is located in organelles not distinguishable from the ones containing acid phosphatase, a known marker enzyme of Giardia lysosome‐like peripheral vesicles. Contrary to the rat lysosomal enzyme, Giardia cathepsin C behaved like a membrane protein. Moreover, the enzyme was not solubilized by Triton X‐100 or Trit…

Evidence: 38 • authority: 92

A diverse Palaeoproterozoic microbial ecosystem implies early eukaryogenesis.. Microbial interactions may lead to major events in life and planetary evolution, such as eukaryogenesis, the birth of complex nucleated cells. In synergy with microbiology, cellular palaeobiology may shed some light on this very ancient and debated affair and its circumstances. The 1.78-1.73 Ga McDermott Formation, McArthur Basin (Australia), preserves a microfossil assemblage that provides unique insights into the evolution of early eukaryotes. The fossil cells display a level of morphological complexity, disparity and plasticity requiring a complex cytoskeleton and an endomembrane system, pushing back the minim…

Evidence: — • authority: 92

Why a Chloroplast Needs Its Own Genome Tethered to the Thylakoid Membrane-Co-Location for Redox Regulation.. A chloroplast is a subcellular organelle of photosynthesis in plant and algal cells. A chloroplast's genome encodes proteins of the photosynthetic electron transport chain along with proteins required to express them. Chloroplast-encoded photosynthetic proteins function in close contact with proteins whose precursors are encoded in the cell nucleus for cytosolic synthesis, import into the chloroplast, and subsequent processing. Protein complexes of photosynthetic electron transport thus contain polypeptides with one of two quite different sites of synthesis. Most chloroplast proteins…

Evidence: — • authority: 92

Nucleosome Assembly Protein 1 in Dinoflagellate Cells Without Architectural Nucleosomes.. Nucleosome assembly protein 1 (NAP1) is highly conserved across eukaryotes, yet its biochemical function, particularly its proposed role as a histone chaperone, remains unresolved. Dinoflagellates, including Karenia brevis ( Kb ) and Crypthecodinium cohnii ( Cc ), lack architectural nucleosomes and express core histones at unusually low levels, yet retain abundant NAP1 transcripts encoding two to three distinct homologs. Confocal immunolocalization of K. brevis showed strong nuclear signals for both homologs, between chromosomes and at the nucleolus, with higher nuclear-to-cytoplasmic ratios in G 2 tha…