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83-400: Its name is due to the soft brushed hand of the fabric, similar to mole fur. Though mole pelts have been used to make fur clothing, they are not referred to as "moleskin". Moleskin is also a term for soft, dense adhesive pads stuck to the skin to prevent blisters . Moleskin is woven of carded cotton yarn in a dense weft -faced satin weave. The surface is napped or shorn to "produce

166-441: A coordinate covalent bond , completing the octahedral group of six ligands. This reversible bonding with oxygen is why hemoglobin is so useful for transporting oxygen around the body. Oxygen binds in an "end-on bent" geometry where one oxygen atom binds to Fe and the other protrudes at an angle. When oxygen is not bound, a very weakly bonded water molecule fills the site, forming a distorted octahedron . Even though carbon dioxide

249-888: A permit . Problems cited as caused by moles include contamination of silage with soil particles, making it unpalatable to livestock , the covering of pasture with fresh soil reducing its size and yield, damage to agricultural machinery by the exposure of stones, damage to young plants through disturbance of the soil, weed invasion of pasture through exposure of freshly tilled soil, and damage to drainage systems and watercourses. Other species such as weasels and voles may use mole tunnels to gain access to enclosed areas or plant roots. Moles burrow and raise molehills , killing parts of lawns . They can undermine plant roots, indirectly causing damage or death. Moles do not eat plant roots. Moles are controlled with traps such as mole-catchers, smoke bombs, and poisons such as calcium carbide , which produces acetylene gas to drive moles away. Strychnine

332-459: A toxin that can paralyze earthworms, moles are able to store their still-living prey for later consumption. They construct special underground "larders" for just this purpose; researchers have discovered such larders with over a thousand earthworms in them. Before eating earthworms, moles pull them between their squeezed paws to force the collected earth and dirt out of the worm's gut. The star-nosed mole can detect, catch and eat food faster than

415-459: A conformational change in the protein and facilitates the release of oxygen. Protons bind at various places on the protein, while carbon dioxide binds at the α-amino group. Carbon dioxide binds to hemoglobin and forms carbaminohemoglobin . This decrease in hemoglobin's affinity for oxygen by the binding of carbon dioxide and acid is known as the Bohr effect . The Bohr effect favors the T state rather than

498-470: A connection is possible between this species-specific trait and the male genital apparatus in female moles of many mole species ( gonads with testicular and ovary tissues). Moles are omnivores , but their diet primarily consists of earthworms and other small invertebrates found in the soil. The mole runs are in reality "worm traps", the mole sensing when a worm falls into the tunnel and quickly running along to kill and eat it. Because their saliva contains

581-420: A decrease in blood pH. Ventilation , or breathing, may reverse this condition by removal of carbon dioxide , thus causing a shift up in pH. Hemoglobin exists in two forms, a taut (tense) form (T) and a relaxed form (R). Various factors such as low pH, high CO 2 and high 2,3 BPG at the level of the tissues favor the taut form, which has low oxygen affinity and releases oxygen in the tissues. Conversely,

664-469: A dimer made up of identical globin subunits, which then evolved to assemble into a tetrameric architecture after the duplication. The development of α and β genes created the potential for hemoglobin to be composed of multiple distinct subunits, a physical composition central to hemoglobin's ability to transport oxygen. Having multiple subunits contributes to hemoglobin's ability to bind oxygen cooperatively as well as be regulated allosterically. Subsequently,

747-407: A high pH, low CO 2 , or low 2,3 BPG favors the relaxed form, which can better bind oxygen. The partial pressure of the system also affects O 2 affinity where, at high partial pressures of oxygen (such as those present in the alveoli), the relaxed (high affinity, R) state is favoured. Inversely, at low partial pressures (such as those present in respiring tissues), the (low affinity, T) tense state

830-454: A lesser extent to American marsupials, such as opossums , than they are to placental mammals, such as golden or Talpidae moles. Class Mammalia Moles' pelts have a velvety texture not found in surface animals. Surface-dwelling animals tend to have longer fur with a natural tendency for the nap to lie in a particular direction, but to facilitate their burrowing lifestyle, mole pelts are short and very dense and have no particular direction to

913-658: A main branch of placental mammals called the Afrosoricida . This means that they share a closer common ancestor with such existing afrosoricids as elephants , manatees and aardvarks than they do with other placental mammals, such as true Talpidae moles. As marsupials, these moles are even more distantly related to true talpid moles than golden moles are, both of which belong to the Eutheria , or placental mammals. This means that they are more closely related to such existing Australian marsupials as kangaroos or koalas , and even to

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996-491: A phosphate "pocket" on the fish hemoglobin molecule, which stabilizes the tense state and therefore decreases oxygen affinity. GTP reduces hemoglobin oxygen affinity much more than ATP, which is thought to be due to an extra hydrogen bond formed that further stabilizes the tense state. Under hypoxic conditions, the concentration of both ATP and GTP is reduced in fish red blood cells to increase oxygen affinity. A variant hemoglobin, called fetal hemoglobin (HbF, α 2 γ 2 ),

1079-454: A red blood cell's dry weight (excluding water), and around 35% of the total weight (including water). Hemoglobin has an oxygen-binding capacity of 1.34   mL of O 2 per gram, which increases the total blood oxygen capacity seventy-fold compared to dissolved oxygen in blood plasma alone. The mammalian hemoglobin molecule can bind and transport up to four oxygen molecules. Hemoglobin also transports other gases. It carries off some of

1162-512: A set of alpha-helix structural segments connected together in a globin fold arrangement. Such a name is given because this arrangement is the same folding motif used in other heme/globin proteins such as myoglobin . This folding pattern contains a pocket that strongly binds the heme group. A heme group consists of an iron (Fe) ion held in a heterocyclic ring, known as a porphyrin . This porphyrin ring consists of four pyrrole molecules cyclically linked together (by methine bridges) with

1245-414: A single, sickle-shaped bone that develops later and differently from the other fingers during embryogenesis from a transformed sesamoid bone in the wrist , independently evolved but similar to the giant panda thumb. This supernumerary digit is species-specific, as it is not present in shrews , the mole's closest relatives. Androgenic steroids are known to affect the growth and formation of bones, and

1328-412: A special form of hemoglobin that has a higher affinity to oxygen than other forms. In addition, moles use oxygen more effectively by reusing the exhaled air, and can survive in low-oxygen environments such as burrows. Moles have polydactyl forepaws: each has an extra thumb (also known as a prepollex) next to the regular thumb . While the mole's other digits have multiple joints, the prepollex has

1411-430: A suede-like finish". Moleskin fabric is commonly used to make trousers , also referred to as "moleskins", that are similar to jeans in terms of cut and construction. They similarly started as working menswear, but are now also much more widely worn. Moleskin-like fabric with an adhesive backing is used to prevent or treat blisters , cut with a hole in the centre to provide relief to the affected skin. The thickness of

1494-506: Is diamagnetic , whereas both oxygen and high-spin iron(II) are paramagnetic . Experimental evidence strongly suggests heme iron is in the iron(III) oxidation state in oxyhemoglobin, with the oxygen existing as superoxide anion (O 2 ) or in a covalent charge-transfer complex. Deoxygenated hemoglobin (deoxyhemoglobin) is the form of hemoglobin without the bound oxygen. The absorption spectra of oxyhemoglobin and deoxyhemoglobin differ. The oxyhemoglobin has significantly lower absorption of

1577-475: Is a colorless, odorless and tasteless gas, and poses a potentially fatal threat, carbon monoxide detectors have become commercially available to warn of dangerous levels in residences. When hemoglobin combines with CO, it forms a very bright red compound called carboxyhemoglobin , which may cause the skin of CO poisoning victims to appear pink in death, instead of white or blue. When inspired air contains CO levels as low as 0.02%, headache and nausea occur; if

1660-450: Is a higher offspring survival rate among Tibetan women with high oxygen saturation genotypes residing at 4,000 m. Natural selection seems to be the main force working on this gene because the mortality rate of offspring is significantly lower for women with higher hemoglobin-oxygen affinity when compared to the mortality rate of offspring from women with low hemoglobin-oxygen affinity. While the exact genotype and mechanism by which this occurs

1743-473: Is bound to amino groups of the globin proteins to form carbaminohemoglobin ; this mechanism is thought to account for about 10% of carbon dioxide transport in mammals. Nitric oxide can also be transported by hemoglobin; it is bound to specific thiol groups in the globin protein to form an S-nitrosothiol, which dissociates into free nitric oxide and thiol again, as the hemoglobin releases oxygen from its heme site. This nitric oxide transport to peripheral tissues

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1826-420: Is called the root effect . This is seen in bony fish. It is necessary for hemoglobin to release the oxygen that it binds; if not, there is no point in binding it. The sigmoidal curve of hemoglobin makes it efficient in binding (taking up O 2 in lungs), and efficient in unloading (unloading O 2 in tissues). In people acclimated to high altitudes, the concentration of 2,3-Bisphosphoglycerate (2,3-BPG) in

1909-423: Is carried by hemoglobin, it does not compete with oxygen for the iron-binding positions but is bound to the amine groups of the protein chains attached to the heme groups. The iron ion may be either in the ferrous Fe or in the ferric Fe state, but ferrihemoglobin ( methemoglobin ) (Fe ) cannot bind oxygen. In binding, oxygen temporarily and reversibly oxidizes (Fe ) to (Fe ) while oxygen temporarily turns into

1992-412: Is denoted as α 2 β 2 . The subunits are structurally similar and about the same size. Each subunit has a molecular weight of about 16,000  daltons , for a total molecular weight of the tetramer of about 64,000 daltons (64,458 g/mol). Thus, 1 g/dL=0.1551 mmol/L. Hemoglobin A is the most intensively studied of the hemoglobin molecules. In human infants, the fetal hemoglobin molecule

2075-430: Is favoured. Additionally, the binding of oxygen to the iron(II) heme pulls the iron into the plane of the porphyrin ring, causing a slight conformational shift. The shift encourages oxygen to bind to the three remaining heme units within hemoglobin (thus, oxygen binding is cooperative). Classically, the iron in oxyhemoglobin is seen as existing in the iron(II) oxidation state. However, the complex of oxygen with heme iron

2158-444: Is found in the developing fetus , and binds oxygen with greater affinity than adult hemoglobin. This means that the oxygen binding curve for fetal hemoglobin is left-shifted (i.e., a higher percentage of hemoglobin has oxygen bound to it at lower oxygen tension), in comparison to that of adult hemoglobin. As a result, fetal blood in the placenta is able to take oxygen from maternal blood. Hemoglobin also carries nitric oxide (NO) in

2241-467: Is hypothesized to assist oxygen transport in tissues, by releasing vasodilatory nitric oxide to tissues in which oxygen levels are low. The binding of oxygen is affected by molecules such as carbon monoxide (for example, from tobacco smoking , exhaust gas , and incomplete combustion in furnaces). CO competes with oxygen at the heme binding site. Hemoglobin's binding affinity for CO is 250 times greater than its affinity for oxygen, Since carbon monoxide

2324-455: Is made up of 2 α chains and 2 γ chains. The γ chains are gradually replaced by β chains as the infant grows. The four polypeptide chains are bound to each other by salt bridges , hydrogen bonds , and the hydrophobic effect . In general, hemoglobin can be saturated with oxygen molecules (oxyhemoglobin), or desaturated with oxygen molecules (deoxyhemoglobin). Oxyhemoglobin is formed during physiological respiration when oxygen binds to

2407-426: Is not yet clear, selection is acting on these women's ability to bind oxygen in low partial pressures, which overall allows them to better sustain crucial metabolic processes. Hemoglobin (Hb) is synthesized in a complex series of steps. The heme part is synthesized in a series of steps in the mitochondria and the cytosol of immature red blood cells, while the globin protein parts are synthesized by ribosomes in

2490-512: Is possible instead of extermination to simply remove the earth of the molehills as they appear, leaving their permanent galleries for the moles to continue their existence underground. However, when the tunnels are near the surface in soft ground or after heavy rain, they may collapse, leaving (small) unsightly furrows in the lawn. William Buckland , known for eating every animal he could, opined that mole meat tasted vile. Moles can inadvertently help archaeologists by bringing small artifacts to

2573-545: Is protected by a reduction system to keep this from happening. Nitric oxide is capable of converting a small fraction of hemoglobin to methemoglobin in red blood cells. The latter reaction is a remnant activity of the more ancient nitric oxide dioxygenase function of globins. Carbon di oxide occupies a different binding site on the hemoglobin. At tissues, where carbon dioxide concentration is higher, carbon dioxide binds to allosteric site of hemoglobin, facilitating unloading of oxygen from hemoglobin and ultimately its removal from

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2656-399: Is tasked with oxygen transport. The α- and β-like globin genes encode the individual subunits of the protein. The predecessors of these genes arose through another duplication event also after the gnathosome common ancestor derived from jawless fish, approximately 450–500 million years ago. Ancestral reconstruction studies suggest that the preduplication ancestor of the α and β genes was

2739-466: Is weakly attracted to magnetic fields . In contrast, oxygenated hemoglobin exhibits diamagnetism , a weak repulsion from a magnetic field. Scientists agree that the event that separated myoglobin from hemoglobin occurred after lampreys diverged from jawed vertebrates . This separation of myoglobin and hemoglobin allowed for the different functions of the two molecules to arise and develop: myoglobin has more to do with oxygen storage while hemoglobin

2822-517: The Pleistocene . This was also found in hummingbirds that inhabit the Andes. Hummingbirds already expend a lot of energy and thus have high oxygen demands and yet Andean hummingbirds have been found to thrive in high altitudes. Non-synonymous mutations in the hemoglobin gene of multiple species living at high elevations ( Oreotrochilus, A. castelnaudii, C. violifer, P. gigas, and A. viridicuada ) have caused

2905-423: The blood carries oxygen from the respiratory organs ( lungs or gills ) to the other tissues of the body, where it releases the oxygen to enable aerobic respiration which powers an animal's metabolism . A healthy human has 12   to 20   grams of hemoglobin in every 100   mL of blood. Hemoglobin is a metalloprotein , a chromoprotein , and globulin . In mammals , hemoglobin makes up about 96% of

2988-441: The golden moles of southern Africa and the marsupial moles of Australia. While difficult to distinguish from each other, they are most easily distinguished from true moles by shovel-like patches on their noses, which they use in tandem with their abbreviated forepaws to swim through sandy soils. The golden moles belong to the same branch on the phylogenetic tree as the tenrecs , called Tenrecomorpha , which, in turn, stem from

3071-597: The superoxide ion, thus iron must exist in the +2 oxidation state to bind oxygen. If superoxide ion associated to Fe is protonated, the hemoglobin iron will remain oxidized and incapable of binding oxygen. In such cases, the enzyme methemoglobin reductase will be able to eventually reactivate methemoglobin by reducing the iron center. In adult humans, the most common hemoglobin type is a tetramer (which contains four subunit proteins) called hemoglobin A , consisting of two α and two β subunits non-covalently bound, each made of 141 and 146 amino acid residues, respectively. This

3154-434: The vasculature (this hemoglobin-synthetic RNA in fact gives the reticulocyte its reticulated appearance and name). Hemoglobin has a quaternary structure characteristic of many multi-subunit globular proteins. Most of the amino acids in hemoglobin form alpha helices , and these helices are connected by short non-helical segments. Hydrogen bonds stabilize the helical sections inside this protein, causing attractions within

3237-465: The 2–4 young are born in March and April after a gestation period of about 1 month. Moles are allegedly solitary creatures, coming together only to mate. Territories may overlap, but moles avoid each other and males may fight fiercely if they meet. The family Talpidae contains all the true moles and some of their close relatives. Those species called " shrew moles " represent an intermediate form between

3320-420: The 660 nm wavelength than deoxyhemoglobin, while at 940 nm its absorption is slightly higher. This difference is used for the measurement of the amount of oxygen in a patient's blood by an instrument called a pulse oximeter . This difference also accounts for the presentation of cyanosis , the blue to purplish color that tissues develop during hypoxia . Deoxygenated hemoglobin is paramagnetic ; it

3403-530: The CO concentration is increased to 0.1%, unconsciousness will follow. In heavy smokers, up to 20% of the oxygen-active sites can be blocked by CO. In similar fashion, hemoglobin also has competitive binding affinity for cyanide (CN ), sulfur monoxide (SO), and sulfide (S ), including hydrogen sulfide (H 2 S). All of these bind to iron in heme without changing its oxidation state, but they nevertheless inhibit oxygen-binding, causing grave toxicity. The iron atom in

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3486-405: The R state. (shifts the O 2 -saturation curve to the right ). Conversely, when the carbon dioxide levels in the blood decrease (i.e., in the lung capillaries), carbon dioxide and protons are released from hemoglobin, increasing the oxygen affinity of the protein. A reduction in the total binding capacity of hemoglobin to oxygen (i.e. shifting the curve down, not just to the right) due to reduced pH

3569-542: The beta subunit is coded by gene HBB on chromosome 11. The amino acid sequences of the globin subunits usually differ between species, with the difference growing with evolutionary distance. For example, the most common hemoglobin sequences in humans, bonobos and chimpanzees are completely identical, with exactly the same alpha and beta globin protein chains. Human and gorilla hemoglobin differ in one amino acid in both alpha and beta chains, and these differences grow larger between less closely related species. Mutations in

3652-420: The binding of oxygen to the remaining three monomers' heme groups, thus saturating the hemoglobin molecule with oxygen. In the tetrameric form of normal adult hemoglobin, the binding of oxygen is, thus, a cooperative process . The binding affinity of hemoglobin for oxygen is increased by the oxygen saturation of the molecule, with the first molecules of oxygen bound influencing the shape of the binding sites for

3735-402: The blood is increased, which allows these individuals to deliver a larger amount of oxygen to tissues under conditions of lower oxygen tension . This phenomenon, where molecule Y affects the binding of molecule X to a transport molecule Z, is called a heterotropic allosteric effect. Hemoglobin in organisms at high altitudes has also adapted such that it has less of an affinity for 2,3-BPG and so

3818-468: The body after the oxygen has been released to tissues undergoing metabolism. This increased affinity for carbon dioxide by the venous blood is known as the Bohr effect . Through the enzyme carbonic anhydrase , carbon dioxide reacts with water to give carbonic acid , which decomposes into bicarbonate and protons : Hence, blood with high carbon dioxide levels is also lower in pH (more acidic ). Hemoglobin can bind protons and carbon dioxide, which causes

3901-564: The body's respiratory carbon dioxide (about 20–25% of the total) as carbaminohemoglobin , in which CO 2 binds to the heme protein . The molecule also carries the important regulatory molecule nitric oxide bound to a thiol group in the globin protein, releasing it at the same time as oxygen. Hemoglobin is also found in other cells, including in the A9 dopaminergic neurons of the substantia nigra , macrophages , alveolar cells , lungs, retinal pigment epithelium, hepatocytes, mesangial cells of

3984-482: The country. Hundreds of pelts are cut into rectangles and sewn together to make a coat. The natural color is taupe , (derived from the French noun taupe meaning mole) but it is readily dyed any color. The term " moleskin " for a tough cotton fabric is in common use today. Moles are considered agricultural pests in some countries, while in others, such as Germany , they are a protected species , but may be killed with

4067-426: The cytosol. Production of Hb continues in the cell throughout its early development from the proerythroblast to the reticulocyte in the bone marrow . At this point, the nucleus is lost in mammalian red blood cells, but not in birds and many other species. Even after the loss of the nucleus in mammals, residual ribosomal RNA allows further synthesis of Hb until the reticulocyte loses its RNA soon after entering

4150-488: The early 1990s were made of "moleskin" fabric in a greyish olive-drab colour, but the German moleskin was not shorn and thus had a flat, smooth outer side. Nonetheless, it was a tough, densely woven material, strongly resistant to wind and abrasion. Military snipers occasionally wrap the stocks of their rifles in moleskin to absorb sweat and prevent slippage. Trousers made from moleskin were popular with British workers during

4233-589: The end of the nineteenth century due to the insulating and windproof qualities of the fabric. Cotton sateen is a variant of moleskin. It utilises cheaper short- staple cotton to create a softer feeling fabric that is relatively fragile and wears quickly. Mole (animal) Moles are small mammals adapted to a subterranean lifestyle . They have cylindrical bodies, velvety fur, very small, inconspicuous eyes and ears, reduced hindlimbs , and short, powerful forelimbs with large paws adapted for digging. The word "mole" most commonly refers to many species in

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4316-784: The family Talpidae (which are named after the Latin word for mole, talpa ). True moles are found in most parts of North America, Europe and Asia. Other mammals referred to as moles include the African golden moles and the Australian marsupial moles , which have a similar ecology and lifestyle to true moles, but are unrelated. Moles may be viewed as pests to gardeners, but they provide positive contributions to soil, gardens, and ecosystems, including soil aeration, feeding on slugs and small creatures that eat plant roots, and providing prey for other wildlife. They eat earthworms and other small invertebrates in

4399-403: The genes for hemoglobin can result in variants of hemoglobin within a single species, although one sequence is usually "most common" in each species. Many of these mutations cause no disease, but some cause a group of hereditary diseases called hemoglobinopathies . The best known hemoglobinopathy is sickle-cell disease , which was the first human disease whose mechanism was understood at

4482-409: The globin part of the molecule. This improves oxygen delivery in the periphery and contributes to the control of respiration. NO binds reversibly to a specific cysteine residue in globin; the binding depends on the state (R or T) of the hemoglobin. The resulting S-nitrosylated hemoglobin influences various NO-related activities such as the control of vascular resistance, blood pressure and respiration. NO

4565-399: The heme component of the protein hemoglobin in red blood cells. This process occurs in the pulmonary capillaries adjacent to the alveoli of the lungs. The oxygen then travels through the blood stream to be dropped off at cells where it is utilized as a terminal electron acceptor in the production of ATP by the process of oxidative phosphorylation . It does not, however, help to counteract

4648-401: The heme group must initially be in the ferrous (Fe ) oxidation state to support oxygen and other gases' binding and transport (it temporarily switches to ferric during the time oxygen is bound, as explained above). Initial oxidation to the ferric (Fe ) state without oxygen converts hemoglobin into "hem i globin" or methemoglobin , which cannot bind oxygen. Hemoglobin in normal red blood cells

4731-574: The higher pressures at sea level. Recent studies of deer mice found mutations in four genes that can account for differences between high- and low-elevation populations. It was found that the genes of the two breeds are "virtually identical—except for those that govern the oxygen-carrying capacity of their hemoglobin. . . . The genetic difference enables highland mice to make more efficient use of their oxygen." Mammoth hemoglobin featured mutations that allowed for oxygen delivery at lower temperatures, thus enabling mammoths to migrate to higher latitudes during

4814-539: The human eye can follow. Breeding season for a mole depends on species, but is generally from February through May. Males search for females by letting out high-pitched squeals and tunneling through foreign areas. The gestation period of the Eastern (North America) mole (Scalopus aquaticus) is approximately 42 days. Three to five young are born, mainly in March and early April. Townsend's moles mate in February and March, and

4897-400: The iron complex, it causes the iron atom to move back toward the center of the plane of the porphyrin ring (see moving diagram). At the same time, the imidazole side-chain of the histidine residue interacting at the other pole of the iron is pulled toward the porphyrin ring. This interaction forces the plane of the ring sideways toward the outside of the tetramer, and also induces a strain in

4980-425: The iron ion bound in the center. The iron ion, which is the site of oxygen binding, coordinates with the four nitrogen atoms in the center of the ring, which all lie in one plane. The heme is bound strongly (covalently) to the globular protein via the N atoms of the imidazole ring of F8 histidine residue (also known as the proximal histidine) below the porphyrin ring. A sixth position can reversibly bind oxygen by

5063-709: The kidney, endometrial cells, cervical cells, and vaginal epithelial cells. In these tissues, hemoglobin absorbs unneeded oxygen as an antioxidant , and regulates iron metabolism . Excessive glucose in the blood can attach to hemoglobin and raise the level of hemoglobin A1c. Hemoglobin and hemoglobin-like molecules are also found in many invertebrates, fungi, and plants. In these organisms, hemoglobins may carry oxygen, or they may transport and regulate other small molecules and ions such as carbon dioxide, nitric oxide, hydrogen sulfide and sulfide. A variant called leghemoglobin serves to scavenge oxygen away from anaerobic systems such as

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5146-409: The microphone to pick up the unwanted noises of the singer's clothing rubbing up against the body and top of the lavalier. Attaching a small strip of moleskin around the microphone body will dramatically reduce the amount of noise created by the singer's clothing and, consequently, reduces the amount of unwanted noise picked up by the lavalier microphone. West German army uniforms from the 1960s until

5229-421: The mole, or smoking its burrow. Devices are also sold to trap the mole in its burrow, when one sees the "mole hill" moving and therefore knows where the animal is, and then stabbing it. Other humane options are also possible including humane traps that capture the mole alive so it may be transported elsewhere. In many contexts including ordinary gardens, the damage caused by moles to lawns is mostly visual, and it

5312-513: The molecular level. A mostly separate set of diseases called thalassemias involves underproduction of normal and sometimes abnormal hemoglobins, through problems and mutations in globin gene regulation . All these diseases produce anemia . Variations in hemoglobin sequences, as with other proteins, may be adaptive. For example, hemoglobin has been found to adapt in different ways to the thin air at high altitudes, where lower partial pressure of oxygen diminishes its binding to hemoglobin compared to

5395-487: The molecular mass of hemoglobin to n × 16000 ( n =number of iron atoms per hemoglobin molecule, now known to be 4), the first determination of a protein's molecular mass. This "hasty conclusion" drew ridicule from colleagues who could not believe that any molecule could be so large. However, Gilbert Smithson Adair confirmed Engelhart's results in 1925 by measuring the osmotic pressure of hemoglobin solutions. Although blood had been known to carry oxygen since at least 1794,

5478-431: The molecule, which then causes each polypeptide chain to fold into a specific shape. Hemoglobin's quaternary structure comes from its four subunits in roughly a tetrahedral arrangement. In most vertebrates, the hemoglobin molecule is an assembly of four globular protein subunits. Each subunit is composed of a protein chain tightly associated with a non-protein prosthetic heme group. Each protein chain arranges into

5561-798: The moles and their shrew ancestors, and as such may not be fully described by the article. Moles were traditionally classified in the order Insectivora , but that order has since been abandoned because it has been shown to not be monophyletic . Moles are now classified with shrews and hedgehogs , in the more narrowly defined order Eulipotyphla . Many groups of burrowing animals ( pink fairy armadillos , tuco-tucos , mole rats , mole crickets , pygmy mole crickets , and mole crabs ) have independently developed close physical similarities with moles due to convergent evolution ; two of these are so similar to true moles, they are commonly called and thought of as "moles" in common English, although they are completely unrelated to true moles or to each other. These are

5644-513: The nap. This makes it easy for moles to move backwards underground, as their fur is not "brushed the wrong way". The leather is extremely soft and supple. Queen Alexandra , the wife of Edward VII of the United Kingdom , ordered a mole-fur garment to start a fashion that would create a demand for mole fur, thereby turning what had been a serious pest problem in Scotland into a lucrative industry for

5727-411: The next ones, in a way favorable for binding. This positive cooperative binding is achieved through steric conformational changes of the hemoglobin protein complex as discussed above; i.e., when one subunit protein in hemoglobin becomes oxygenated, a conformational or structural change in the whole complex is initiated, causing the other subunits to gain an increased affinity for oxygen. As a consequence,

5810-441: The nitrogen-fixing nodules of leguminous plants, preventing oxygen poisoning. The medical condition hemoglobinemia , a form of anemia , is caused by intravascular hemolysis , in which hemoglobin leaks from red blood cells into the blood plasma . In 1825, Johann Friedrich Engelhart discovered that the ratio of iron to protein is identical in the hemoglobins of several species. From the known atomic mass of iron, he calculated

5893-553: The oxygen binding curve of hemoglobin is sigmoidal , or S -shaped, as opposed to the normal hyperbolic curve associated with noncooperative binding. The dynamic mechanism of the cooperativity in hemoglobin and its relation with low-frequency resonance has been discussed. Besides the oxygen ligand , which binds to hemoglobin in a cooperative manner, hemoglobin ligands also include competitive inhibitors such as carbon monoxide (CO) and allosteric ligands such as carbon dioxide (CO 2 ) and nitric oxide (NO). The carbon dioxide

5976-414: The oxygen-carrying property of hemoglobin was described by Hünefeld in 1840. In 1851, German physiologist Otto Funke published a series of articles in which he described growing hemoglobin crystals by successively diluting red blood cells with a solvent such as pure water, alcohol or ether, followed by slow evaporation of the solvent from the resulting protein solution. Hemoglobin's reversible oxygenation

6059-441: The protein helix containing the histidine as it moves nearer to the iron atom. This strain is transmitted to the remaining three monomers in the tetramer, where it induces a similar conformational change in the other heme sites such that binding of oxygen to these sites becomes easier. As oxygen binds to one monomer of hemoglobin, the tetramer's conformation shifts from the T (tense) state to the R (relaxed) state. This shift promotes

6142-491: The protein to have less of an affinity for inositol hexaphosphate (IHP), a molecule found in birds that has a similar role as 2,3-BPG in humans; this results in the ability to bind oxygen in lower partial pressures. Birds' unique circulatory lungs also promote efficient use of oxygen at low partial pressures of O 2 . These two adaptations reinforce each other and account for birds' remarkable high-altitude performance. Hemoglobin adaptation extends to humans, as well. There

6225-410: The protein will be shifted more towards its R state. In its R state, hemoglobin will bind oxygen more readily, thus allowing organisms to perform the necessary metabolic processes when oxygen is present at low partial pressures. Animals other than humans use different molecules to bind to hemoglobin and change its O 2 affinity under unfavorable conditions. Fish use both ATP and GTP . These bind to

6308-433: The protein's chemical properties and function. The amino acid sequence of any polypeptide is translated from a segment of DNA, the corresponding gene . There is more than one hemoglobin gene. In humans, hemoglobin A (the main form of hemoglobin in adults) is coded by genes HBA1 , HBA2 , and HBB . Alpha 1 and alpha 2 subunits are respectively coded by genes HBA1 and HBA2 close together on chromosome 16, while

6391-895: The soil. In Middle English, moles were known as moldwarps . The expression "don't make a mountain out of a molehill" (which means "exaggerating problems") was first recorded in Tudor times. By the era of Early Modern English , the mole was also known in English as mouldywarp or mouldiwarp , a word having cognates in other Germanic languages such as German ( Maulwurf ), and Danish , Norwegian , Swedish and Icelandic ( muldvarp , moldvarp , mullvad , moldvarpa ), where muld/mull/mold refers to soil and varp/vad/varpa refers to throwing, hence "one who throws soil" or "dirt-tosser". Male moles are called "boars"; females are called "sows". Moles have been found to tolerate higher levels of carbon dioxide than other mammals, because their blood cells have

6474-496: The surface through their digging. By examining molehills for sherds and other small objects, archaeologists can find evidence of human habitation. Hemoglobin Hemoglobin ( haemoglobin , Hb or Hgb ) is a protein containing iron that facilitates the transportation of oxygen in red blood cells . Almost all vertebrates contain hemoglobin, with the sole exception of the fish family, Channichthyidae . Hemoglobin in

6557-413: The surrounding moleskin further protects the blister from additional friction. Medical moleskin-like fabric with adhesive backing is also commonly used in video and/or audio productions when using a lavalier microphone . When further concealment of a lavalier microphone is needed in these types of productions, it can be worn underneath a layer or layers of the singer's clothing. This would normally cause

6640-452: The α gene also underwent a duplication event to form the HBA1 and HBA2 genes. These further duplications and divergences have created a diverse range of α- and β-like globin genes that are regulated so that certain forms occur at different stages of development. Most ice fish of the family Channichthyidae have lost their hemoglobin genes as an adaptation to cold water. When oxygen binds to

6723-488: Was also used for this purpose in the past. The most common method now is Phostoxin or Talunex tablets. They contain aluminium phosphide and are inserted in the mole tunnels, where they turn into phosphine gas (not be confused with phosgene gas). More recently, high-grade nitrogen gas has proven effective at killing moles, with the added advantage of having no polluting effect to the environment. Other common defensive measures include cat litter and blood meal , to repel

6806-455: Was described a few years later by Felix Hoppe-Seyler . With the development of X-ray crystallography , it became possible to sequence protein structures. In 1959, Max Perutz determined the molecular structure of hemoglobin. For this work he shared the 1962 Nobel Prize in Chemistry with John Kendrew , who sequenced the globular protein myoglobin . The role of hemoglobin in the blood

6889-612: Was elucidated by French physiologist Claude Bernard . The name hemoglobin (or haemoglobin ) is derived from the words heme (or haem ) and globin , reflecting the fact that each subunit of hemoglobin is a globular protein with an embedded heme group. Each heme group contains one iron atom, that can bind one oxygen molecule through ion-induced dipole forces. The most common type of hemoglobin in mammals contains four such subunits. Hemoglobin consists of protein subunits ( globin molecules), which are polypeptides , long folded chains of specific amino acids which determine

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