Nutrition

Question

This piglix contains articles or sub-piglix about Nutrition

Answer 1

Parasitic nutrition

Parasitic nutrition is a mode of heterotrophic nutrition where an organism (known as a parasite) lives on the body surface or inside the body of another type of organism (known as a host). The parasite obtains nutrition directly from the body of the host. Since these parasites derive their nourishment from their host, this symbiotic interaction is often described as harmful to the host. Parasites are dependent on their host for survival, since the host provides nutrition and protection. As a result of this dependence, parasites have considerable modifications to optimise parasitic nutrition and therefore their survival.

Parasites are divided into two groups: endoparasites and ectoparasites. Endoparasites are parasites that live inside the body of the host, whereas ectoparasites are parasites that live on the outer surface of the host and generally attach themselves during feeding. Due to the different strategies of endoparasites and ectoparasites they require different adaptations in order to acquire nutrients from their host.

Parasites require nutrients to carry out essential functions including reproduction and growth. Essentially, the nutrients required from the host are carbohydrates, amino acids and lipids. Carbohydrates are utilised to generate energy, whilst amino acids and fatty acids are involved in the synthesis of macromolecules and the production of eggs. Most parasites are heterotrophs, so they therefore are unable to synthesise their own 'food' i.e. organic compounds and must acquire these from their host.

enderoparasite is parasites which live inside the body of the host. This group includes helminths, trematodes and cestodes. Endoparasites are two groups of parasites: intercellular and intracellular parasites. Intercellular parasites live in spaces within the host e.g. the alimentary canal, whereas intracellular parasites live in cells within the host e.g. erythrocytes. Intracellular parasites typically rely on a third organism, a vector, to transmit the parasite between hosts. Rather than requiring adaptations to penetrate the host, as ectoparasites do, endoparasites are in a nutrient-rich location so they instead have adaptations to maximise nutrient absorption. Endoparasites have a readily available and renewable supply of nutrients inside the host, which in some cases is pre-digested by the host, so mechanisms of nutrient absorption across their body surface is a common feature. As part of their life cycle strategy, endoparasites must also be able to transmit from within the host body and survive the hostile environment within the host. Only by achieving this can they benefit from acquiring nutrition in this way.

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Answer 2

Parenteral nutrition

Parenteral nutrition

Parenteral nutrition (PN) is the feeding of a person intravenously, bypassing the usual process of eating and digestion. The person receives nutritional formulae that contain nutrients such as glucose, salts, amino acids, lipids and added vitamins and dietary minerals. It is called total parenteral nutrition (TPN) or total nutrient admixture (TNA) when no significant nutrition is obtained by other routes, and partial parenteral nutrition (PPN) when nutrition is also partially enteric. It may be called peripheral parenteral nutrition (PPN) when administered through vein access in a limb rather than through a central vein as central venous nutrition (CVN).

Total nutrition (TPN) is provided when the gastrointestinal tract is nonfunctional because of an interruption in its continuity (it is blocked, or has a leak - a fistula) or because its absorptive capacity is impaired. It has been used for comatose patients, although enteral feeding is usually preferable, and less prone to complications. Parenteral nutrition is used to prevent malnutrition in patients who are unable to obtain adequate nutrients by oral or enteral routes.

TPN may be the only feasible option for providing nutrition to patients who do not have a functioning gastrointestinal tract or who have disorders requiring complete bowel rest, including bowel obstruction,short bowel syndrome,Gastroschisis, prolonged diarrhea regardless of its cause, high-output fistula, very severe Crohn's disease or ulcerative colitis, and certain pediatric GI disorders including congenital GI anomalies and necrotizing enterocolitis.

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Answer 3

Peonidin

Peonidin

Peonidin is an O-methylated anthocyanidin derived from Cyanidin, and a primary plant pigment. Peonidin gives purplish-red hues to flowers such as the peony, from which it takes its name, and roses. It is also present in some blue flowers, such as the morning glory.

Like most anthocyanidins, it is pH sensitive, and changes from red to blue as pH rises because anthocyanidins are highly conjugated chromophores. When the pH is changed, the extent of the conjugation (of the double bonds) is altered, which alters the wavelength of light energy absorbed by the molecule. (Natural anthocyanidins are most stable in a very low pH environment; at pH 8.0, most become colorless.) At pH 2.0, peonidin is cherry red; at 3.0 a strong yellowish pink; at 5.0 it is grape red-purple; and at 8.0 it becomes deep blue; unlike many anthocyanidins, however, it is stable at higher pH, and has been isolated as a blue colorant from the brilliant "Heavenly Blue" morning glory (Ipomoea tricolor Cav cv).

Because of its unusual color stability, a cafeyl-acylated buffered formulation of it has been patented for use as food coloring.

Peonidin, like many anthocyanidins, has shown potent inhibitory and apoptotic effects on cancer cells in vitro, notably metastatic human breast cancer cells. A very large question, however, has been raised about anthocyanidins' penetration and retention in human cells in vivo, due to their rapid elimination from the human body.

By far the greatest dietary source of peonidin is raw cranberries, which contain 42 mg per 100 g of fruit. Blueberries, plums, grapes, and cherries also contain significant amounts, ranging from 5 to 12 mg/100 g. Only fresh fruit has been shown to contain significant peonidin; frozen blueberries have been shown to contain almost none. Peonidin has been found in concentrations of up to 40 mg per 100 g (cooked) of certain cultivars of purple fleshed sweet potatoes; the amount of peonidin varies greatly across cultivars. It has also been isolated from raw black rice and black bananas.

The higher level of peonidin in fresh fruit corresponds to the rule of thumb that more natural fruit is healthier. Specifically, the amount of phenolic compounds in cranberries has been found to be inversely correlated with fruit size and crop yield.

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Answer 4

Peptide YY

Peptide YY

2L60, 2DEZ, 2DF0

5697

217212

ENSG00000131096

ENSMUSG00000017311

P10082

Q9EPS2

NM_004160

NM_145435
NM_001346771

NP_004151

NP_663410.1
NP_001333700
NP_663410

Peptide YY (PYY) also known as peptide tyrosine tyrosine or pancreatic peptide YY_3-36 is a peptide that in humans is encoded by the PYY gene. Peptide YY is a short (36-amino acid) peptide released by cells in the ileum and colon in response to feeding. In the blood, gut, and other elements of periphery, PYY acts to reduce appetite; similarly, when injected directly into the central nervous system, PYY is also anorexigenic, i.e., it reduces appetite.

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Answer 5

Phosphatidylserine

Phosphatidylserine

Phosphatidylserine (abbreviated Ptd-L-Ser or PS) is a phospholipid and is a component of the cell membrane. It plays a key role in cell cycle signaling, specifically in relationship to apoptosis.

Phosphatidylserine is a phospholipid (more specifically a glycerophospholipid). It consists of two fatty acids attached in ester linkage to the first and second carbon of glycerol and serine attached through a phosphodiester linkage to the third carbon of the glycerol.

Phosphatidylserine coming from plants and phosphatidylserine coming from animals differ in fatty acid composition.

Phosphatidylserine(s) are actively held facing the cytosolic (inner) side of the cell membrane by the enzyme flippase. However, when a cell undergoes apoptosis, phosphatidylserine is no longer restricted to the cytosolic side by flippase. Instead scramblase catalyzes the rapid exchange of phosphatidylserine between the two sides. When the phosphatidylserines flip to the extracellular (outer) surface of the cell, they act as a signal for macrophages to engulf the cells.

Phosphatidylserine plays a role in blood coagulation (also known as clotting). When circulating platelets encounter the site of an injury, collagen and thrombin -mediated activation causes externalization of phosphatidylserine (PS) from the inner membrane layer, where it serves as a pro-coagulant surface. This surface acts to orient coagulation proteases, specifically tissue factor (TF) and factor VII (the tenase complex), facilitating further proteolysis, activation of factor X, and ultimately generating thrombin.

In the coagulation disorder Scott syndrome, the mechanism in platelets for transportation of PS from the inner platelet membrane surface to the outer membrane surface is defective. It is characterized as a mild bleeding disorder stemming from the patient's deficiency in thrombin synthesis.

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Answer 6

Polyunsaturated fat

Polyunsaturated fats are lipids in which the constituent hydrocarbon chain possesses two or more carbon–carbon double bonds. Polyunsaturated fat can be found mostly in nuts, seeds, fish, algae, leafy greens, and krill. "Unsaturated" refers to the fact that the molecules contain less than the maximum amount of hydrogen (if there were no double bonds). These materials exist as cis or trans isomers depending on the geometry of the double bond.

Saturated fats have hydrocarbon chains which can be most readily aligned. The hydrocarbon chains in trans fats align more readily than those in cis fats, but less well than those in saturated fats. This means that, in general, the melting points of fats increase from cis to trans unsaturated and then to saturated. See the section on chemical structure of fats for more information.

The position of the carbon-carbon double bonds in carboxylic acid chains in fats is designated by Greek letters. The carbon atom closest to the carboxyl group is the alpha carbon, the next carbon is the beta carbon and so on. In fatty acids the carbon atom of the methyl group at the end of the hydrocarbon chain is called the omega carbon because omega is the last letter of the Greek alphabet. Omega-3 fatty acids have a double bond three carbons away from the methyl carbon, whereas omega-6 fatty acids have a double bond six carbons away from the methyl carbon. The illustration below shows the omega-6 fatty acid, linoleic acid.

While it is the nutritional aspects of polyunsaturated fats that are generally of greatest interest, these materials do also have non-food applications. Drying oils, which polymerize on exposure to oxygen to form solid films, are polyunsaturated fats. The most common ones are linseed (flax seed) oil, tung oil, poppy seed oil, perilla oil, and walnut oil. These oils are used to make paints and varnishes.

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Answer 7

Phytoestrogens

Phytoestrogens are plant-derived xenoestrogens (see estrogen) not generated within the endocrine system but consumed by eating phytoestrogenic plants. Also called "dietary estrogens", they are a diverse group of naturally occurring nonsteroidal plant compounds that, because of their structural similarity with estradiol (17-β-estradiol), have the ability to cause estrogenic or/and antiestrogenic effects, by sitting in and blocking receptor sites against estrogen.

Their name comes from the Greek phyto ("plant") and estrogen, the hormone which gives fertility to female mammals. The word "estrus" - Greek οίστρος - means "sexual desire", and "gene" - Greek γόνο - is "to generate". It has been hypothesized that plants use phytoestrogens as part of their natural defence against the overpopulation of herbivore animals by controlling female fertility.

The similarities, at molecular level, of estrogens and phytoestrogens allow them to mildly mimic and sometimes act as antagonists of estrogen. Phytoestrogens were first observed in 1926, but it was unknown if they could have any effect in human or animal metabolism. In the 1940s and early 1950s, it was noticed that some pastures of subterranean clover and red clover (phytoestrogen-rich plants) had adverse effects on the fecundity of grazing sheep. Researchers are exploring the nutritional role of phytoestrogens in the regulation of cholesterol and the maintenance of proper bone density post-menopause. Evidence is accruing that phytoestrogens may have protective action against diverse health disorders, such as prostate, breast, bowel, and other cancers, cardiovascular disease, brain function disorders and osteoporosis,

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Answer 8

Phytic acid

Phytic acid

Phytic acid (known as inositol hexakisphosphate (IP6), inositol polyphosphate, or phytate when in salt form), discovered in 1903, a saturated cyclic acid, is the principal storage form of phosphorus in many plant tissues, especially bran and seeds. It can be found in cereals and grains.

Catabolites of phytic acid are called lower inositol polyphosphates. Examples are inositol penta- (IP5), tetra- (IP4), and triphosphate (IP3).

Phosphorus and inositol in phytate form are not, in general, bioavailable to nonruminant animals because these animals lack the digestive enzyme phytase required to remove phosphate from the inositol in the phytate molecule. Ruminants are readily able to digest phytate because of the phytase produced by rumen microorganisms.

In most commercial agriculture, nonruminant , such as swine, fowl, and fish, are fed mainly grains, such as maize, legumes, and soybeans. Because phytate from these grains and beans is unavailable for absorption, the unabsorbed phytate passes through the gastrointestinal tract, elevating the amount of phosphorus in the manure. Excess phosphorus excretion can lead to environmental problems, such as eutrophication.

Also, viable low-phytic acid mutant lines have been developed in several crop species in which the seeds have drastically reduced levels of phytic acid and concomitant increases in inorganic phosphorus. However, germination problems have reportedly hindered the use of these cultivars thus far. This may be due to phytic acid's critical role in both phosphorus and metal ion storage.

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Answer 9

Polyunsaturated fatty acid

Polyunsaturated fatty acids (PUFAs) are fatty acids that contain more than one double bond in their backbone. This class includes many important compounds, such as essential fatty acids and those that give drying oils their characteristic property.

Polyunsaturated fatty acids can be classified in various groups by their chemical structure:

These fatty acids have 2 or more cis double bonds that are separated from each other by a single methylene bridge (-CH
2- unit). This form is also sometimes called a divinylmethane pattern.

The essential fatty acids are all omega-3 and -6 methylene-interrupted fatty acids. See more at Essential fatty acids—Nomenclature

Omega-3 fatty acids, polyunsaturated

Omega-6 fatty acids, polyunsaturated

Omega-9 fatty acids, mono- and polyunsaturated

Conjugated fatty acids have two or more conjugated double bonds

The biological effects of the ω-3 and ω-6 fatty acids are largely mediated by their mutual interactions, see Essential fatty acid interactions for detail.

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Answer 10

Price-Pottenger Nutrition Foundation

The Price-Pottenger Nutrition Foundation (PPNF) is a U.S. 501(c)(3) non-profit organization established "to teach the public and professionals about foods, lifestyle habits, healing modalities, and environmental practices that can help people attain vibrant health." Founded in 1952, it was first known as the Weston A. Price Memorial Foundation after the 20th century researcher Weston Price who emphasized the importance of nutrition for health and dentistry. The other half of the foundation's current namesake is Francis M. Pottenger, Jr. whose study of nutrition in cats sparked interest in a diet high in raw animal products including uncooked meats and unpasteurized dairy. In 1969, after Price's death, the organization became the Price Pottenger Foundation, and then the Price Pottenger Nutrition Foundation, which it bears today.

PPNF primarily advocates: 1) that consumption of animal fats is not dangerous to human health, and 2) that mainstream agricultural methods which emphasize the use of synthetic fertilizers and pesticides as well as factory farming and significant processing of whole foods, reduces overall nutritional quality of food and human health. The first set of claims go against the mainstream scientific consensus among researchers, doctors, and nutritionists, that a diet high in saturated fat presents serious risks to cardiovascular health and longevity. The second set of claims is aligned with the increasingly popular organic food movement, although major food growers and producers consistently affirm the taste and nutritional quality of their food as identical or better than organics.

PPNF now houses over 10,000 books and publications, including the works of Dr. Royal Lee, Dr. Melvin Page, Dr. Emanuel Cheraskin, Dr. William Albrecht, and others. The foundation today owns and protects the original copyrighted material of Weston A. Price, DDS, and Francis M. Pottenger, Jr., MD. They continue to republish Price’s Nutrition and Physical Degeneration, and Pottenger's Pottenger’s Cats – A Study in Nutrition.

Price was a dentist from Cleveland, Ohio, whose 1939 book, Nutritional and Physical Degeneration, describes the fieldwork he did in the 1920s and 1930s among various world cultures, with the original goal of recording and studying the dental health and development of pre-industrial populations including tribal Africans and Pacific islanders, Inuit, North and South American natives, and Australian aborigines. The book contains numerous photographs of the people he studied, and includes comparison photographs of the teeth and facial structure of people who lived on their traditional diet and people who had adopted or grown up on industrialized food. In certain instances it was possible for Price to examine and photograph traditional and industrialized eaters from the same family.

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