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Cyanobacterium
Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blue-green algae, although they are not usually scientifically classified as algae. They appear to have originated in a freshwater or terrestrial environment. Sericytochromatia, the proposed name of the paraphyletic and most basal group, is the ancestor of both the non-photosynthetic group Melainabacteria and the photosynthetic cyanobacteria, also called Oxyphotobacteria. Cyanobacteria use photosynthetic pigments, such as carotenoids, phycobilins, and various forms of chlorophyll, which absorb energy from light. Unlike heterotrophic prokaryotes, cyanobacteria have internal membranes. These are flattened sacs called thylakoids where photosynthesis is performed. Phototrophic eukaryotes such as green plants perform photosynthesis in plastids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chroococcidiopsidales
''Chroococcidiopsis'' is a photosynthetic, coccoidal bacterium. A diversity of species and cultures exist within the genus, with a diversity of phenotypes. Some extremophile members of the order Chroococidiopsidales are known for their ability to survive harsh environmental conditions, including both high and low temperatures, ionizing radiation, and high salinity. Desiccation resistance The ability of ''Chroococcidiopsis'' to resist desiccation in arid environments is due in part because it colonizes the underside of translucent rocks. The underside of these rocks provides enough condensed moisture for growth while the rock's translucent nature allows just enough light to reach the organism for photosynthesis to occur. Mars colonization Due to its resistance to harsh environmental conditions, especially low temperature, low moisture, and radiation tolerance, ''Chroococcidiopsis'' has been thought of as an organism capable of living on Mars. Scientists have speculated about ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular microalgae, such as ''Chlorella,'' ''Prototheca'' and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga which may grow up to in length. Most are aquatic and autotrophic (they generate food internally) and lack many of the distinct cell and tissue types, such as stomata, xylem and phloem that are found in land plants. The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the ''Charophyta'', a division of green algae which includes, for example, ''Spirogyra'' and stoneworts. No definition of algae is generally accepted. One definition is that algae "have chlorophyll ''a'' as their primary photosynthetic pigment and lack a sterile covering of cells around their re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gloeobacterales
''Gloeobacter'' is a genus of cyanobacteria. It is the sister group to all other cyanobacteria. ''Gloeobacter'' is unique among cyanobacteria in not having thylakoids, which are characteristic for all other cyanobacteria and chloroplasts. Instead, the light-harvesting complexes (also called phycobilisomes), that consist of different proteins, sit on the inside of the plasma membrane among the (cytoplasm). Subsequently, the proton gradient in ''Gloeobacter'' is created over the plasma membrane, where it forms over the thylakoid membrane in cyanobacteria and chloroplasts. The whole genome of ''G. violaceus'' (strain PCC 7421) and of ''G. kilaueensis'' have been sequenced. Many genes for photosystem I and II were found missing, likely related to the fact that photosynthesis in these bacteria does not take place in the thylakoid membrane as in other cyanobacteria, but in the plasma membrane. Description ''Gloeobacter violaceus'' produces several pigments, including chlorophyll a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryote
Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacteria and Archaea (both prokaryotes) make up the other two domains. The eukaryotes are usually now regarded as having emerged in the Archaea or as a sister of the Asgard archaea. This implies that there are only two domains of life, Bacteria and Archaea, with eukaryotes incorporated among archaea. Eukaryotes represent a small minority of the number of organisms, but, due to their generally much larger size, their collective global biomass is estimated to be about equal to that of prokaryotes. Eukaryotes emerged approximately 2.3–1.8 billion years ago, during the Proterozoic eon, likely as flagellated phagotrophs. Their name comes from the Greek εὖ (''eu'', "well" or "good") and κάρυον (''karyon'', "nut" or "kernel"). E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosynthesis
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in carbohydrate molecules, such as sugars and starches, which are synthesized from carbon dioxide and water – hence the name ''photosynthesis'', from the Greek ''phōs'' (), "light", and ''synthesis'' (), "putting together". Most plants, algae, and cyanobacteria perform photosynthesis; such organisms are called photoautotrophs. Photosynthesis is largely responsible for producing and maintaining the oxygen content of the Earth's atmosphere, and supplies most of the energy necessary for life on Earth. Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins called reaction centers that contain green chlorophyll (and other colored) pigments/chromophor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cylindrospermum
''Cylindrospermum'' is a genus of filamentous cyanobacteria found in terrestrial and aquatic environments. In terrestrial ecosystems, ''Cylindrospermum'' is found in soils, and in aquatic ones, it commonly grows as part of the periphyton Periphyton is a complex mixture of algae, cyanobacteria, heterotrophic microbes, and detritus that is attached to submerged surfaces in most aquatic ecosystems. The related term Aufwuchs (German "surface growth" or "overgrowth") refers to the col ... on aquatic plants. The genus is heterocystous ( nitrogen-fixing) cyanobacteria. References Nostocaceae Cyanobacteria genera Taxa named by Friedrich Traugott Kützing {{cyanobacteria-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-negative Bacteria
Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall sandwiched between an inner cytoplasmic cell membrane and a bacterial outer membrane. Gram-negative bacteria are found in virtually all environments on Earth that support life. The gram-negative bacteria include the model organism ''Escherichia coli'', as well as many pathogenic bacteria, such as ''Pseudomonas aeruginosa'', '' Chlamydia trachomatis'', and ''Yersinia pestis''. They are a significant medical challenge as their outer membrane protects them from many antibiotics (including penicillin), detergents that would normally damage the inner cell membrane, and lysozyme, an antimicrobial enzyme produced by animals that forms part of the innate immune system. Additionally, the outer leaflet of this membrane comprises a complex lipopol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorophyll
Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to absorb energy from light. Chlorophylls absorb light most strongly in the blue portion of the electromagnetic spectrum as well as the red portion. Conversely, it is a poor absorber of green and near-green portions of the spectrum. Hence chlorophyll-containing tissues appear green because green light, diffusively reflected by structures like cell walls, is less absorbed. Two types of chlorophyll exist in the photosystems of green plants: chlorophyll ''a'' and ''b''. History Chlorophyll was first isolated and named by Joseph Bienaimé Caventou and Pierre Joseph Pelletier in 1817. The presence of magnesium in chlorophyll was discovered in 1906, and was that element's first detection in living tissue. After initial work done by German ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phycobilin
Phycobilins (from Greek: '' (phykos)'' meaning "alga", and from Latin: ''bilis'' meaning "bile") are light-capturing bilins found in cyanobacteria and in the chloroplasts of red algae, glaucophytes and some cryptomonads (though not in green algae and plants). Most of their molecules consist of a chromophore which makes them coloured. They are unique among the photosynthetic pigments in that they are bonded to certain water-soluble proteins, known as phycobiliproteins. Phycobiliproteins then pass the light energy to chlorophylls for photosynthesis. The phycobilins are especially efficient at absorbing red, orange, yellow, and green light, wavelengths that are not well absorbed by chlorophyll ''a''. Organisms growing in shallow waters tend to contain phycobilins that can capture yellow/red light, while those at greater depth often contain more of the phycobilins that can capture green light, which is relatively more abundant there. The phycobilins fluoresce at a particu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carotenoid
Carotenoids (), also called tetraterpenoids, are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, corn, tomatoes, canaries, flamingos, salmon, lobster, shrimp, and daffodils. Carotenoids can be produced from fats and other basic organic metabolic building blocks by all these organisms. It is also produced by endosymbiotic bacteria in whiteflies. Carotenoids from the diet are stored in the fatty tissues of animals, and exclusively carnivorous animals obtain the compounds from animal fat. In the human diet, absorption of carotenoids is improved when consumed with fat in a meal. Cooking carotenoid-containing vegetables in oil and shredding the vegetable both increase carotenoid bioavailability. There are over 1,100 known carotenoids which can be further categorized into two classes, xanthophylls (which contain oxygen) and caro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosynthetic Pigment
A photosynthetic pigment (accessory pigment; chloroplast pigment; antenna pigment) is a pigment that is present in chloroplasts or photosynthetic bacteria and captures the light energy necessary for photosynthesis. List of photosynthetic pigments (in order of increasing polarity): * Carotene: an orange pigment * Xanthophyll: a yellow pigment * Phaeophytin ''a'':CHLOROPHYLLS JECFA, 1987 a gray-brown pigment * Phaeophytin ''b'': a yellow-brown pigment * Chlorophyll ''a'': a blue-green pigment * Chlorophyll ''b'': a yel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melainabacteria
Melainabacteria is a phylum related to Cyanobacteria. Organisms belonging to this phylum have been found in the human gut and various aquatic habitats such as groundwater. By analyzing genomes of Melainabacteria, predictions are possible about the cell structure and metabolic abilities. The bacterial cell is similar to cyanobacteria in being surrounded by two membranes. It differs from cyanobacteria in its ability to move by flagella (like gram-negative flagella), though some members (e.g. Gastranaerophilales) lack flagella. Melainabacteria are not able to perform photosynthesis, but obtain energy by fermentation. Phylogeny Classification * Class "Melainabacteria" Soo et al. 2014 Vampirovibrionia"(ACD20) ** Order " Caenarcanales" corrig. Soo et al. 2014 Caenarcaniphilales" Soo et al. 2014">Caenarcaniphilales.html" ;"title="Caenarcaniphilales">Caenarcaniphilales" Soo et al. 2014*** Family "Caenarcanaceae" **** Genus "''Ca.'' Caenarcanum" Soo et al. 2014 ***** "''Ca.'' Caenarca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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