77-437: Traditional groups: The embryophytes ( / ˈ ɛ m b r i ə ˌ f aɪ t s / ) are a clade of plants , also known as Embryophyta ( / ˌ ɛ m b r i ˈ ɒ f ə t ə , - oʊ ˈ f aɪ t ə / ) or land plants . They are the most familiar group of photoautotrophs that make up the vegetation on Earth 's dry lands and wetlands . Embryophytes have a common ancestor with green algae , having emerged within
154-489: A and b to harvest the light energy in sunlight for carbon fixation from carbon dioxide and water in order to synthesize carbohydrates while releasing oxygen as a byproduct . The Embryophytes emerged either a half-billion years ago, at some time in the interval between the mid- Cambrian and early Ordovician , or almost a billion years ago, during the Tonian or Cryogenian, probably from freshwater charophytes ,
231-419: A and b , generally giving them a bright green color. Embryophyte cells also generally have an enlarged central vacuole enclosed by a vacuolar membrane or tonoplast, which maintains cell turgor and keeps the plant rigid. In common with all groups of multicellular algae they have a life cycle which involves alternation of generations . A multicellular haploid generation with a single set of chromosomes –
308-479: A "ladder", with supposedly more "advanced" organisms at the top. Taxonomists have increasingly worked to make the taxonomic system reflect evolution. When it comes to naming , this principle is not always compatible with the traditional rank-based nomenclature (in which only taxa associated with a rank can be named) because not enough ranks exist to name a long series of nested clades. For these and other reasons, phylogenetic nomenclature has been developed; it
385-623: A clade can be described based on two different reference points, crown age and stem age. The crown age of a clade refers to the age of the most recent common ancestor of all of the species in the clade. The stem age of a clade refers to the time that the ancestral lineage of the clade diverged from its sister clade. A clade's stem age is either the same as or older than its crown age. Ages of clades cannot be directly observed. They are inferred, either from stratigraphy of fossils , or from molecular clock estimates. Viruses , and particularly RNA viruses form clades. These are useful in tracking
462-464: A clade of multicellular green algae similar to extant Klebsormidiophyceae . The emergence of the Embryophytes depleted atmospheric CO 2 (a greenhouse gas ), leading to global cooling , and thereby precipitating glaciations . Embryophytes are primarily adapted for life on land, although some are secondarily aquatic . Accordingly, they are often called land plants or terrestrial plants. On
539-525: A combination of the two. The resulting fragments are known as dextrins . The extent of conversion is typically quantified by dextrose equivalent (DE), which is roughly the fraction of the glycosidic bonds in starch that have been broken. These starch sugars are by far the most common starch based food ingredient and are used as sweeteners in many drinks and foods. They include: The modified food starches are E coded according to European Food Safety Authority and INS coded Food Additives according to
616-558: A complex molecular event that can be subdivided into four major steps, namely, granule initiation, coalescence of small granules, phase transition, and expansion. Several proteins have been characterized for their involvement in each of these processes. For instance, a chloroplast membrane-associated protein, MFP1, determines the sites of granule initiation. Another protein named PTST2 binds to small glucan chains and agglomerates to recruit starch synthase 4 (SS4). Three other proteins, namely, PTST3, SS5, and MRC, are also known to be involved in
693-519: A dietary AGE is acrylamide . Recent evidence suggests that the intestinal fermentation of dietary AGEs may be associated with insulin resistance , atherosclerosis , diabetes and other inflammatory diseases. This may be due to the impact of AGEs on intestinal permeability. Starch gelatinization during cake baking can be impaired by sugar competing for water , preventing gelatinization and improving texture. Starch can be hydrolyzed into simpler carbohydrates by acids , various enzymes , or
770-494: A glucose molecule is released. Now, BAM can release another maltose molecule from the remaining chain. This cycle repeats until starch is fully degraded. If BAM comes close to the phosphorylated branching point of the glucose chain, it can no longer release maltose. In order for the phosphorylated chain to be degraded, the enzyme isoamylase (ISA) is required. The products of starch degradation are predominantly maltose and smaller amounts of glucose. These molecules are exported from
847-671: A higher gelatinization temperature than other types of starch, and retains its resistant starch content through baking , mild extrusion and other food processing techniques. It is used as an insoluble dietary fiber in processed foods such as bread, pasta, cookies, crackers, pretzels and other low moisture foods. It is also utilized as a dietary supplement for its health benefits. Published studies have shown that resistant starch helps to improve insulin sensitivity, reduces pro-inflammatory biomarkers interleukin 6 and tumor necrosis factor alpha and improves markers of colonic function. It has been suggested that resistant starch contributes to
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#1732787370746924-456: A lesser extent, sources of refined starch are sweet potato, sago and mung bean. To this day, starch is extracted from more than 50 types of plants. Crude starch is processed on an industrial scale to maltodextrin and glucose syrups and fructose syrups. These massive conversions are mediated by a variety of enzymes, which break down the starch to varying extents. Here breakdown involves hydrolysis, i.e. cleavage of bonds between sugar subunits by
1001-464: A microscopic level, the cells of charophytes are broadly similar to those of chlorophyte green algae, but differ in that in cell division the daughter nuclei are separated by a phragmoplast . They are eukaryotic , with a cell wall composed of cellulose and plastids surrounded by two membranes. The latter include chloroplasts , which conduct photosynthesis and store food in the form of starch , and are characteristically pigmented with chlorophylls
1078-416: A mixture of pigments, binders and thickeners. Coated paper has improved smoothness, hardness, whiteness and gloss and thus improves printing characteristics. Corrugated board adhesives are the next largest application of non-food starches globally. Starch glues are mostly based on unmodified native starches, plus some additive such as borax and caustic soda . Part of the starch is gelatinized to carry
1155-478: A mold in the conventional sense. A tray is filled with native starch and leveled. A positive mold is then pressed into the starch leaving an impression of 1,000 or so jelly beans. The jelly mix is then poured into the impressions and put onto a stove to set. This method greatly reduces the number of molds that must be manufactured. Resistant starch is starch that escapes digestion in the small intestine of healthy individuals. High-amylose starch from wheat or corn has
1232-670: A phosphate at the C-6 position of glucose, close to the chain's 1,6-alpha branching bonds. A second enzyme, phosphoglucan, water dikinase (PWD) phosphorylates the glucose molecule at the C-3 position. After the second phosphorylation, the first degrading enzyme, beta-amylase (BAM) attacks the glucose chain at its non-reducing end. Maltose is the main product released. If the glucose chain consists of three or fewer molecules, BAM cannot release maltose. A second enzyme, disproportionating enzyme-1 (DPE1), combines two maltotriose molecules. From this chain,
1309-450: A precursor to myriad organic building blocks such as nucleic acids , lipids , proteins , and structural polysaccharides such as cellulose . Most green plants store any extra glucose in the form of starch, which is packed into semicrystalline granules called starch or amyloplasts . Toward the end of the growing season, starch accumulates in twigs of trees near the buds. Fruit , seeds , rhizomes , and tubers store starch to prepare for
1386-556: A prefix for several carbon compounds related to or derived from starch (e.g. amyl alcohol , amylose , amylopectin ). Starch grains from the rhizomes of Typha (cattails, bullrushes) as flour have been identified from grinding stones in Europe dating back to 30,000 years ago. Starch grains from sorghum were found on grind stones in caves in Ngalue , Mozambique dating up to 100,000 years ago. Pure extracted wheat starch paste
1463-705: A range of environmental conditions found on land, such as exposure to rain, tolerance of temperature variation, high levels of ultra-violet light, and seasonal dehydration. The preponderance of molecular evidence as of 2006 suggested that the groups making up the embryophytes are related as shown in the cladogram below (based on Qiu et al. 2006 with additional names from Crane et al. 2004). Liverworts [REDACTED] Mosses [REDACTED] Hornworts [REDACTED] Lycophytes [REDACTED] ( ferns and horsetails ) [REDACTED] Angiosperms ( flowering plants ) [REDACTED] Gymnosperms [REDACTED] An updated phylogeny of Embryophytes based on
1540-422: A revised taxonomy based on a concept strongly resembling clades, although the term clade itself would not be coined until 1957 by his grandson, Julian Huxley . German biologist Emil Hans Willi Hennig (1913–1976) is considered to be the founder of cladistics . He proposed a classification system that represented repeated branchings of the family tree, as opposed to the previous systems, which put organisms on
1617-443: A similar type of polysaccharide called floridean starch in their cytosol or periplast . Especially when hydrated, glucose takes up much space and is osmotically active. Starch, on the other hand, being insoluble and therefore osmotically inactive, can be stored much more compactly. The semicrystalline granules generally consist of concentric layers of amylose and amylopectin which can be made bioavailable upon cellular demand in
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#17327873707461694-441: A single cell. In the bryophytes the sporophyte remains dependent on the gametophyte, while in all other embryophytes the sporophyte generation is dominant and capable of independent existence. Embryophytes also differ from algae by having metamers . Metamers are repeated units of development, in which each unit derives from a single cell, but the resulting product tissue or part is largely the same for each cell. The whole organism
1771-429: A suffix added should be e.g. "dracohortian". A clade is by definition monophyletic , meaning that it contains one ancestor which can be an organism, a population, or a species and all its descendants. The ancestor can be known or unknown; any and all members of a clade can be extant or extinct. The science that tries to reconstruct phylogenetic trees and thus discover clades is called phylogenetics or cladistics ,
1848-535: A typical sheet of copy paper for instance, the starch content may be as high as 8%. Both chemically modified and unmodified starches are used in papermaking. In the wet part of the papermaking process, generally called the "wet-end", the starches used are cationic and have a positive charge bound to the starch polymer. These starch derivatives associate with the anionic or negatively charged paper fibers / cellulose and inorganic fillers. Cationic starches together with other retention and internal sizing agents help to give
1925-434: Is waxy maize , others are glutinous rice and waxy potato starch . Waxy starches undergo less retrogradation , resulting in a more stable paste. A maize cultivar with a relatively high proportion of amylose starch, amylomaize , is cultivated for the use of its gel strength and for use as a resistant starch (a starch that resists digestion) in food products. Plants synthesize starch in two types of tissues. The first type
2002-499: Is also used with a similar meaning in other fields besides biology, such as historical linguistics ; see Cladistics § In disciplines other than biology . The term "clade" was coined in 1957 by the biologist Julian Huxley to refer to the result of cladogenesis , the evolutionary splitting of a parent species into two distinct species, a concept Huxley borrowed from Bernhard Rensch . Many commonly named groups – rodents and insects , for example – are clades because, in each case,
2079-403: Is from a Germanic root with the meanings "strong, stiff, strengthen, stiffen". Modern German Stärke (strength, starch) is related and refers to the main historical applications, its uses in textiles: sizing yarn for weaving , and starching linen . The Greek term for starch, "amylon" (ἄμυλον), which means "not milled", is also related. It provides the root amyl , which is used as
2156-476: Is in turn included in the mammal, vertebrate and animal clades. The idea of a clade did not exist in pre- Darwinian Linnaean taxonomy , which was based by necessity only on internal or external morphological similarities between organisms. Many of the better known animal groups in Linnaeus's original Systema Naturae (mostly vertebrate groups) do represent clades. The phenomenon of convergent evolution
2233-444: Is produced by most green plants for energy storage. Worldwide, Starch is a complex carbohydrate found in many plant-based foods, making it a vital part of a balanced diet, and is contained in large amounts in staple foods such as wheat , potatoes , maize (corn), rice , and cassava (manioc). Pure starch is a white, tasteless and odorless powder that is insoluble in cold water or alcohol . It consists of two types of molecules:
2310-515: Is responsible for many cases of misleading similarities in the morphology of groups that evolved from different lineages. With the increasing realization in the first half of the 19th century that species had changed and split through the ages, classification increasingly came to be seen as branches on the evolutionary tree of life . The publication of Darwin's theory of evolution in 1859 gave this view increasing weight. In 1876 Thomas Henry Huxley , an early advocate of evolutionary theory, proposed
2387-477: Is slow but relatively complete within the small intestine. Widely used prepared foods containing starch are bread , pancakes , cereals , noodles , pasta , porridge and tortilla . During cooking with high heat, sugars released from starch can react with amino acids via the Maillard reaction , forming advanced glycation end-products (AGEs), contributing aromas, flavors and texture to foods. One example of
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2464-489: Is still controversial. As an example, see the full current classification of Anas platyrhynchos (the mallard duck) with 40 clades from Eukaryota down by following this Wikispecies link and clicking on "Expand". The name of a clade is conventionally a plural, where the singular refers to each member individually. A unique exception is the reptile clade Dracohors , which was made by haplology from Latin "draco" and "cohors", i.e. "the dragon cohort "; its form with
2541-416: Is storage tissues, for example, cereal endosperm, and storage roots and stems such as cassava and potato. The second type is green tissue, for example, leaves, where many plant species synthesize transitory starch on a daily basis. In both tissue types, starch is synthesized in a plastids (amyloplasts and chloroplasts). The biochemical pathway involves conversion of glucose 1-phosphate to ADP -glucose using
2618-528: Is stored in semi-crystalline granules. Each plant species has a distinctive starch granular size: rice starch is relatively small (about 2 μm), potato starches have larger granules (up to 100 μm) while wheat and tapioca fall in-between. Unlike other botanical sources of starch, wheat starch has a bimodal size distribution, with both smaller and larger granules ranging from 2 to 55 μm. Some cultivated plant varieties have pure amylopectin starch without amylose, known as waxy starches . The most used
2695-438: Is subjected to dry heat, it breaks down to form dextrins , also called "pyrodextrins" in this context. This break down process is known as dextrinization. (Pyro)dextrins are mainly yellow to brown in color and dextrinization is partially responsible for the browning of toasted bread. Starch is the most common carbohydrate in the human diet and is contained in many staple foods . The major sources of starch intake worldwide are
2772-533: Is thus constructed from similar, repeating parts or metamers . Accordingly, these plants are sometimes termed 'metaphytes' and classified as the group Metaphyta (but Haeckel 's definition of Metaphyta places some algae in this group). In all land plants a disc-like structure called a phragmoplast forms where the cell will divide , a trait only found in the land plants in the streptophyte lineage, some species within their relatives Coleochaetales , Charales and Zygnematales , as well as within subaerial species of
2849-402: Is used in the manufacture of various adhesives or glues for book-binding, wallpaper adhesives , paper sack production, tube winding, gummed paper , envelope adhesives, school glues and bottle labeling. Starch derivatives, such as yellow dextrins, can be modified by addition of some chemicals to form a hard glue for paper work; some of those forms use borax or soda ash , which are mixed with
2926-809: The Codex Alimentarius : INS 1400, 1401, 1402, 1403 and 1405 are in the EU food ingredients without an E-number. Typical modified starches for technical applications are cationic starches , hydroxyethyl starch , carboxymethylated starches and thiolated starches. As an additive for food processing , food starches are typically used as thickeners and stabilizers in foods such as puddings, custards, soups, sauces, gravies, pie fillings, and salad dressings, and to make noodles and pastas. They function as thickeners, extenders, emulsion stabilizers and are exceptional binders in processed meats. Gummed sweets such as jelly beans and wine gums are not manufactured using
3003-465: The EU the starch industry produced about 11 million tonnes in 2011, with around 40% being used for industrial applications and 60% for food uses, most of the latter as glucose syrups . In 2017 EU production was 11 million ton of which 9,4 million ton was consumed in the EU and of which 54% were starch sweeteners. The US produced about 27.5 million tons of starch in 2017, of which about 8.2 million tons
3080-650: The Latin form cladus (plural cladi ) is used rather than the English form. Clades are the fundamental unit of cladistics , a modern approach to taxonomy adopted by most biological fields. The common ancestor may be an individual, a population , or a species ( extinct or extant ). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed monophyletic (Greek: "one clan") groups. Over
3157-710: The Phragmoplastophyta clade of freshwater charophyte green algae as a sister taxon of Charophyceae , Coleochaetophyceae and Zygnematophyceae . Embryophytes consist of the bryophytes and the polysporangiophytes . Living embryophytes include hornworts , liverworts , mosses , lycophytes , ferns , gymnosperms and angiosperms ( flowering plants ). Embryophytes have diplobiontic life cycles . The embryophytes are informally called "land plants" because they thrive primarily in terrestrial habitats (despite some members having evolved secondarily to live once again in semiaquatic / aquatic habitats ), while
Embryophyte - Misplaced Pages Continue
3234-747: The cereals ( rice , wheat , and maize ) and the root vegetables ( potatoes and cassava ). Many other starchy foods are grown, some only in specific climates, including acorns , arrowroot , arracacha , bananas , barley , breadfruit , buckwheat , canna , colocasia , cuckoo-pint , katakuri , kudzu , malanga , millet , oats , oca , polynesian arrowroot , sago , sorghum , sweet potatoes , rye , taro , chestnuts , water chestnuts , and yams , and many kinds of beans , such as favas , lentils , mung beans , peas , and chickpeas . Before processed foods, people consumed large amounts of uncooked and unprocessed starch-containing plants, which contained high amounts of resistant starch . Microbes within
3311-570: The gametophyte – produces sperm and eggs which fuse and grow into a diploid multicellular generation with twice the number of chromosomes – the sporophyte which produces haploid spores at maturity. The spores divide repeatedly by mitosis and grow into a gametophyte, thus completing the cycle. Embryophytes have two features related to their reproductive cycles which distinguish them from all other plant lineages. Firstly, their gametophytes produce sperm and eggs in multicellular structures (called ' antheridia ' and ' archegonia '), and fertilization of
3388-444: The mosses (Bryophyta), hornworts (Anthocerotophyta), and liverworts (Marchantiophyta), are relatively small plants, often confined to environments that are humid or at least seasonally moist. They are limited by their reliance on water needed to disperse their gametes ; a few are truly aquatic. Most are tropical, but there are many arctic species. They may locally dominate the ground cover in tundra and Arctic–alpine habitats or
3465-413: The addition of water. Some sugars are isomerized. The processes have been described as occurring in two phases: liquefaction and saccharification. The liquefaction converts starch into dextrins . Amylase is a key enzyme for producing dextrin. The saccharification converts dextrin into maltoses and glucose. Diverse enzymes are used in this second phase, including pullanase and other amylases. If starch
3542-666: The algae order Trentepohliales , and appears to be essential in the adaptation towards a terrestrial life style. The green algae and land plants form a clade , the Viridiplantae . According to molecular clock estimates, the Viridiplantae split 1,200 million years ago to 725 million years ago into two clades: chlorophytes and streptophytes . The chlorophytes, with around 700 genera, were originally marine algae, although some groups have since spread into fresh water . The streptophyte algae (i.e. excluding
3619-707: The enzyme glucose-1-phosphate adenylyltransferase . This step requires energy in the form of ATP . A number of starch synthases available in plastids then adds the ADP-glucose via α-1,4- glycosidic bond to a growing chain of glucose residues, liberating ADP . The ADP-glucose is almost certainly added to the non-reducing end of the amylose polymer, as the UDP-glucose is added to the non-reducing end of glycogen during glycogen synthesis . The small glucan chain, further agglomerate to form initials of starch granules. The biosynthesis and expansion of granules represent
3696-429: The epiphyte flora in rain forest habitats. Clade In biological phylogenetics , a clade (from Ancient Greek κλάδος (kládos) 'branch'), also known as a monophyletic group or natural group , is a grouping of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree . In the taxonomical literature, sometimes
3773-422: The formulation, and the process is allowed to heat and cure to form the eventual rigid wall board. The starches act as a glue for the cured gypsum rock with the paper covering, and also provide rigidity to the board. A solution of triiodide (I 3 ) (formed by mixing iodine and potassium iodide ) can be used to test for starch. The colorless solution turns dark blue in the presence of starch. The strength of
3850-571: The glucose chains, creating the branched amylopectin. The starch debranching enzyme (DBE) isoamylase removes some of these branches. Several isoforms of these enzymes exist, leading to a highly complex synthesis process. The starch that is synthesized in plant leaves during the day is transitory: it serves as an energy source at night. Enzymes catalyze release of glucose from the granules. The insoluble, highly branched starch chains require phosphorylation in order to be accessible for degrading enzymes. The enzyme glucan, water dikinase (GWD) installs
3927-546: The group consists of a common ancestor with all its descendant branches. Rodents, for example, are a branch of mammals that split off after the end of the period when the clade Dinosauria stopped being the dominant terrestrial vertebrates 66 million years ago. The original population and all its descendants are a clade. The rodent clade corresponds to the order Rodentia, and insects to the class Insecta. These clades include smaller clades, such as chipmunk or ant , each of which consists of even smaller clades. The clade "rodent"
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#17327873707464004-473: The health benefits of intact whole grains. A cell-free chemoenzymatic process has been demonstrated to synthesize starch from CO 2 and hydrogen.y. The chemical pathway of 11 core reactions was drafted by computational pathway design and converts CO 2 to starch at a rate that is ~8.5-fold higher than starch synthesis in maize . Papermaking is the largest non-food application for starches globally, consuming many millions of metric tons annually. In
4081-519: The land plants) have around 122 genera; they adapted to fresh water very early in their evolutionary history and have not spread back into marine environments. Some time during the Ordovician , streptophytes invaded the land and began the evolution of the embryophyte land plants. Present day embryophytes form a clade. Becker and Marin speculate that land plants evolved from streptophytes because living in fresh water pools pre-adapted them to tolerate
4158-447: The large intestine ferment or consume the starch, producing short-chain fatty acids , which are used as energy, and support the maintenance and growth of the microbes. Upon cooking, starch is transformed from an insoluble, difficult-to-digest granule into readily accessible glucose chains with very different nutritional and functional properties. In current diets, highly processed foods are more easily digested and release more glucose in
4235-590: The last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades; that is, taxa that are not monophyletic . Some of the relationships between organisms that the molecular biology arm of cladistics has revealed include that fungi are closer relatives to animals than they are to plants, archaea are now considered different from bacteria , and multicellular organisms may have evolved from archaea. The term "clade"
4312-518: The latter term coined by Ernst Mayr (1965), derived from "clade". The results of phylogenetic/cladistic analyses are tree-shaped diagrams called cladograms ; they, and all their branches, are phylogenetic hypotheses. Three methods of defining clades are featured in phylogenetic nomenclature : node-, stem-, and apomorphy-based (see Phylogenetic nomenclature§Phylogenetic definitions of clade names for detailed definitions). The relationship between clades can be described in several ways: The age of
4389-401: The linear and helical amylose and the branched amylopectin . Depending on the plant, starch generally contains 20 to 25% amylose and 75 to 80% amylopectin by weight. Glycogen , the energy reserve of animals, is a more highly branched version of amylopectin. In industry, starch is often converted into sugars, for example by malting . These sugars may be fermented to produce ethanol in
4466-511: The manufacture of beer , whisky and biofuel . In addition, sugars produced from processed starch are used in many processed foods. Mixing most starches in warm water produces a paste, such as wheatpaste , which can be used as a thickening, stiffening or gluing agent. The principal non-food, industrial use of starch is as an adhesive in the papermaking process. A similar paste, clothing or laundry starch , can be applied to certain textile goods before ironing to stiffen them. The word "starch"
4543-533: The mid eighth century production of paper that was sized with wheat starch started in the Arabic world. Laundry starch was first described in England in the beginning of the 15th century and was essential to make 16th century ruffed collars . Plants produce glucose from carbon dioxide and water by photosynthesis . The glucose is used to generate the chemical energy required for general metabolism as well as
4620-399: The necessary strength properties to the paper web formed in the papermaking process ( wet strength ), and to provide strength to the final paper sheet (dry strength). In the dry end of the papermaking process, the paper web is rewetted with a starch based solution. The process is called surface sizing . Starches used have been chemically, or enzymatically depolymerized at the paper mill or by
4697-404: The next growing season. Young plants live on this stored energy in their roots, seeds, and fruits until they can find suitable soil in which to grow. The starch is also consumed at night when photosynthesis is not occurring. Green algae and land-plants store their starch in the plastids , whereas red algae , glaucophytes , cryptomonads , dinoflagellates and the parasitic apicomplexa store
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#17327873707464774-437: The ovum takes place within the archegonium rather than in the external environment. Secondly, the initial stage of development of the fertilized egg (the zygote ) into a diploid multicellular sporophyte, takes place within the archegonium where it is both protected and provided with nutrition. This second feature is the origin of the term 'embryophyte' – the fertilized egg develops into a protected embryo, rather than dispersing as
4851-429: The physicochemical properties as well as energy release of different types of starches. In addition, cooking and food processing significantly impacts starch digestibility and energy release. Starch has been classified as rapidly digestible starch, slowly digestible starch and resistant starch, depending upon its digestion profile. Raw starch granules resist digestion by human enzymes and do not break down into glucose in
4928-503: The plant. Amylose consists of long chains derived from glucose molecules connected by α-1,4- glycosidic linkage . Amylopectin is highly branched but also derived from glucose interconnected by α-1,6- glycosidic linkages. The same type of linkage is found in the animal reserve polysaccharide glycogen . By contrast, many structural polysaccharides such as chitin , cellulose, and peptidoglycan are linked by β-glycosidic bonds , which are more resistant to hydrolysis. Within plants, starch
5005-470: The plastid to the cytosol, maltose via the maltose transporter and glucose by the plastidic glucose translocator (pGlcT). These two sugars are used for sucrose synthesis. Sucrose can then be used in the oxidative pentose phosphate pathway in the mitochondria, to generate ATP at night. In addition to starchy plants consumed directly, 66 million tonnes of starch were processed industrially in 2008. By 2011, production had increased to 73 million tons. In
5082-477: The process of starch granule initiation. Furthermore, two proteins named ESV and LESV play a role in the aqueous-to-crystalline phase transition of glucan chains. Several catalytically active starch synthases, such as SS1, SS2, SS3, and GBSS, are critical for starch granule biosynthesis and play a catalytic role at each step of granule biogenesis and expansion. In addition to above proteins, starch branching enzymes (BEs) introduces α-1,6-glycosidic bonds between
5159-450: The related green algae are primarily aquatic. Embryophytes are complex multicellular eukaryotes with specialized reproductive organs . The name derives from their innovative characteristic of nurturing the young embryo sporophyte during the early stages of its multicellular development within the tissues of the parent gametophyte . With very few exceptions, embryophytes obtain biological energy by photosynthesis , using chlorophyll
5236-670: The resulting blue color depends on the amount of amylose present. Waxy starches with little or no amylose present will color red. Benedict's test and Fehling's test is also done to indicate the presence of starch. In the US, the Occupational Safety and Health Administration (OSHA) has set the legal limit ( Permissible exposure limit ) for starch exposure in the workplace as 15 mg/m total exposure and 5 mg/m respiratory exposure over an eight-hour workday. The National Institute for Occupational Safety and Health (NIOSH) has set
5313-414: The slurry of uncooked starches and prevent sedimentation. This opaque glue is called a SteinHall adhesive. The glue is applied on tips of the fluting. The fluted paper is pressed to paper called liner. This is then dried under high heat, which causes the rest of the uncooked starch in glue to swell/gelatinize. This gelatinizing makes the glue a fast and strong adhesive for corrugated board production. Starch
5390-450: The small intestine - they reach the large intestine instead and function as prebiotic dietary fiber . When starch granules are fully gelatinized and cooked, the starch becomes easily digestible and releases glucose quickly within the small intestine. When starchy foods are cooked and cooled, some of the glucose chains re-crystallize and become resistant to digestion again. Slowly digestible starch can be found in raw cereals, where digestion
5467-414: The small intestine—less starch reaches the large intestine and more energy is absorbed by the body. It is thought that this shift in energy delivery (as a result of eating more processed foods) may be one of the contributing factors to the development of metabolic disorders of modern life, including obesity and diabetes. The amylose/amylopectin ratio, molecular weight and molecular fine structure influences
5544-472: The spread of viral infections . HIV , for example, has clades called subtypes, which vary in geographical prevalence. HIV subtype (clade) B, for example is predominant in Europe, the Americas and Japan, whereas subtype A is more common in east Africa. Starch Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds . This polysaccharide
5621-436: The starch industry (oxidized starch). The size/starch solutions are applied to the paper web by means of various mechanical presses (size presses). Together with surface sizing agents the surface starches impart additional strength to the paper web and additionally provide water hold out or "size" for superior printing properties. Starch is also used in paper coatings as one of the binders for the coating formulations which include
5698-449: The starch solution at 50–70 °C (122–158 °F) to create a very good adhesive. Sodium silicate can be added to reinforce these formula. A related large non-food starch application is in the construction industry, where starch is used in the gypsum wall board manufacturing process. Chemically modified or unmodified starches are added to the stucco containing primarily gypsum . Top and bottom heavyweight sheets of paper are applied to
5775-973: The work by Novíkov & Barabaš-Krasni 2015 and Hao and Xue 2013 with plant taxon authors from Anderson, Anderson & Cleal 2007 and some additional clade names. Puttick et al./Nishiyama et al. are used for the basal clades. Anthocerotophytina (Hornworts) Bryophytina (Mosses) Marchantiophytina (Liverworts) † Horneophytopsida [Protracheophytes] † Cooksoniaceae † Aglaophyton † Rhyniopsida † Catenalis † Aberlemnia † Hsuaceae † Renaliaceae † Adoketophyton †? Barinophytopsida † Zosterophyllopsida † Hicklingia † Gumuia † Nothia Lycopodiopsida (Clubmosses, Spikemosses & Quillworts) † Zosterophyllum deciduum † Yunia † Eophyllophyton † Trimerophytopsida † Ibyka † Pauthecophyton † Cladoxylopsida Polypodiopsida (ferns) † Celatheca † Pertica † Progymnosperms (paraphyletic) Spermatophytes (seed plants) The non-vascular land plants, namely
5852-425: Was high fructose syrup , 6.2 million tons was glucose syrups, and 2.5 million tons were starch products. The rest of the starch was used for producing ethanol (1.6 billion gallons). The starch industry extracts and refines starches from crops by wet grinding, washing, sieving and drying. Today, the main commercial refined starches are cornstarch , tapioca , arrowroot, and wheat, rice, and potato starches . To
5929-666: Was used in Ancient Egypt , possibly to glue papyrus . The extraction of starch is first described in the Natural History of Pliny the Elder around 77–79 CE . Romans used it also in cosmetic creams, to powder the hair and to thicken sauces. Persians and Indians used it to make dishes similar to gothumai wheat halva . Rice starch as surface treatment of paper has been used in paper production in China since 700 CE. In
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