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Lactose Tolerance
Lactase persistence or lactose tolerance is the continued activity of the lactase enzyme in adulthood, allowing the digestion of lactose in milk. In most mammals, the activity of the enzyme is dramatically reduced after weaning. In some human populations though, lactase persistence has recently Evolution, evolved as an adaptation to the consumption of nonhuman milk and dairy products beyond infancy. Lactase persistence is very high among northern Europeans. Worldwide, most people are lactase ''non''-persistent, and are affected by varying degrees of lactose intolerance as adults. However, lactase persistence and lactose intolerance can overlap. Global distribution of the phenotype The distribution of the lactase persistence (LP) phenotype, or the ability to digest lactose into adulthood, is not homogeneous in the world. Lactase persistence frequencies are highly variable. In Europe, the distribution of the lactase persistence phenotype is Cline (biology), clinal, with frequencies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactase
Lactase () is an enzyme produced by many organisms and is essential to the complete digestion of whole milk. It breaks down the sugar lactose into its component parts, galactose and glucose. Lactase is found in the brush border of the small intestine of humans and other mammals. People deficient in lactase or lacking functional lactase may experience the symptoms of lactose intolerance after consuming milk products. Microbial β-galactosidase (often loosely referred to as lactase) can be purchased as a food supplement and is added to milk to produce "lactose-free" milk products. Uses Food use Lactase is an enzyme that some people are unable to produce in their small intestine. Technology to produce lactose-free milk, ice cream, and yogurt was developed by the USDA Agricultural Research Service in 1985.Lactase is added to milk, thereby hydrolyzing the lactose in the milk, leaving it slightly sweet but digestible by everyone. Without lactase, lactose-intolerant peopl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indigenous Peoples Of The Americas
In the Americas, Indigenous peoples comprise the two continents' pre-Columbian inhabitants, as well as the ethnic groups that identify with them in the 15th century, as well as the ethnic groups that identify with the pre-Columbian population of the Americas as such. These populations exhibit significant diversity; some Indigenous peoples were historically hunter-gatherers, while others practiced agriculture and aquaculture. Various Indigenous societies developed complex social structures, including pre-contact monumental architecture, organized city, cities, city-states, chiefdoms, state (polity), states, monarchy, kingdoms, republics, confederation, confederacies, and empires. These societies possessed varying levels of knowledge in fields such as Pre-Columbian engineering in the Americas, engineering, Pre-Columbian architecture, architecture, mathematics, astronomy, History of writing, writing, physics, medicine, Pre-Columbian agriculture, agriculture, irrigation, geology, minin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allele
An allele is a variant of the sequence of nucleotides at a particular location, or Locus (genetics), locus, on a DNA molecule. Alleles can differ at a single position through Single-nucleotide polymorphism, single nucleotide polymorphisms (SNP), but they can also have insertions and deletions of up to several thousand base pairs. Most alleles observed result in little or no change in the function or amount of the gene product(s) they code or regulate for. However, sometimes different alleles can result in different observable phenotypic traits, such as different pigmentation. A notable example of this is Gregor Mendel's discovery that the white and purple flower colors in pea plants were the result of a single gene with two alleles. Nearly all multicellular organisms have two sets of chromosomes at some point in their biological life cycle; that is, they are diploid. For a given locus, if the two chromosomes contain the same allele, they, and the organism, are homozygous with re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homozygous
Zygosity (the noun, zygote, is from the Greek "yoked," from "yoke") () is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism. Most eukaryotes have two matching sets of chromosomes; that is, they are diploid. Diploid organisms have the same loci on each of their two sets of homologous chromosomes except that the sequences at these loci may differ between the two chromosomes in a matching pair and that a few chromosomes may be mismatched as part of a chromosomal sex-determination system. If both alleles of a diploid organism are the same, the organism is homozygous at that locus. If they are different, the organism is heterozygous at that locus. If one allele is missing, it is hemizygous, and, if both alleles are missing, it is nullizygous. The DNA sequence of a gene often varies from one individual to another. These gene variants are called alleles. While some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactase
Lactase () is an enzyme produced by many organisms and is essential to the complete digestion of whole milk. It breaks down the sugar lactose into its component parts, galactose and glucose. Lactase is found in the brush border of the small intestine of humans and other mammals. People deficient in lactase or lacking functional lactase may experience the symptoms of lactose intolerance after consuming milk products. Microbial β-galactosidase (often loosely referred to as lactase) can be purchased as a food supplement and is added to milk to produce "lactose-free" milk products. Uses Food use Lactase is an enzyme that some people are unable to produce in their small intestine. Technology to produce lactose-free milk, ice cream, and yogurt was developed by the USDA Agricultural Research Service in 1985.Lactase is added to milk, thereby hydrolyzing the lactose in the milk, leaving it slightly sweet but digestible by everyone. Without lactase, lactose-intolerant peopl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MRNA
In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of Protein biosynthesis, synthesizing a protein. mRNA is created during the process of Transcription (biology), transcription, where an enzyme (RNA polymerase) converts the gene into primary transcript mRNA (also known as pre-mRNA). This pre-mRNA usually still contains introns, regions that will not go on to code for the final amino acid sequence. These are removed in the process of RNA splicing, leaving only exons, regions that will encode the protein. This exon sequence constitutes mature mRNA. Mature mRNA is then read by the ribosome, and the ribosome creates the protein utilizing amino acids carried by transfer RNA (tRNA). This process is known as Translation (biology), translation. All of these processes form part of the central dogma of molecular biology, which describes the flow of geneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypolactasia
Lactose intolerance is caused by a lessened ability or a complete inability to digest lactose, a sugar found in dairy products. Humans vary in the amount of lactose they can tolerate before symptoms develop. Symptoms may include abdominal pain, bloating, diarrhea, flatulence, and nausea. These symptoms typically start thirty minutes to two hours after eating or drinking something containing lactose, with the severity typically depending on the amount consumed. Lactose intolerance does not cause damage to the gastrointestinal tract. Lactose intolerance is due to the lack of the enzyme lactase in the small intestines to break lactose down into glucose and galactose. There are four types: primary, secondary, developmental, and congenital. Primary lactose intolerance occurs as the amount of lactase declines as people grow up. Secondary lactose intolerance is due to injury to the small intestine. Such injury could be the result of infection, celiac disease, inflammatory bowel disea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactase Persistence In The Old World
Lactase () is an enzyme produced by many organisms and is essential to the complete digestion of whole milk. It breaks down the sugar lactose into its component parts, galactose and glucose. Lactase is found in the brush border of the small intestine of humans and other mammals. People deficient in lactase or lacking functional lactase may experience the symptoms of lactose intolerance after consuming milk products. Microbial β-galactosidase (often loosely referred to as lactase) can be purchased as a food supplement and is added to milk to produce "lactose-free" milk products. Uses Food use Lactase is an enzyme that some people are unable to produce in their small intestine. Technology to produce lactose-free milk, ice cream, and yogurt was developed by the USDA Agricultural Research Service in 1985.Lactase is added to milk, thereby hydrolyzing the lactose in the milk, leaving it slightly sweet but digestible by everyone. Without lactase, lactose-intolerant people pass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amasi
Amasi (in Ndebele, Zulu and Xhosa), emasi (in Swazi), karringmelk (in Afrikaans), or mafi (in Sesotho), is a thick curdled sour fermented milk product that is sometimes compared to cottage cheese or plain yogurt but has a much stronger flavor. A staple food in pre-colonial times, it is now a popular snack in South Africa and Lesotho. Preparation Amasi is traditionally prepared by storing unpasteurised cow's milk in a calabash container (, ) or hide sack to allow it to ferment. A calabash is smoked, then milk from the cow is put in a skin bag or bucket, where it ferments for 1 - 5 days, and acquires a sharp acidic taste. The fermenting milk develops a watery substance called ; the remainder is amasi. This thick liquid is mostly poured over mealie meal porridge called pap (). It is traditionally served in a clay pot and it can also be drunk. Commercially, amasi is produced using '' Lactococcus lactis'', along with subspecies, ''Lactococcus lactis subsp. cremonis''. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nguni People
The Nguni people are an ethnolinguistic group of Bantu peoples, Bantu ethnic groups native to Southern Africa where they form the single largest ethnolinguistic community. Predecessors of Nguni people migrated from Central Africa into Southern Africa during the late Iron Age, with offshoots in neighboring colonially-created countries in Southern Africa. Swazi people, Swazi (or Swati) people live in both South Africa and Eswatini, while Ndebele people live in both Ndebele people (South Africa), South Africa and Ndebele people (Zimbabwe), Zimbabwe. The Xhosa people, Xhosa, local to the Eastern Cape, established tribal sub-federations—the Gcaleka, Rharhabe, and Gqunukhwebe—in the 16th century. The homeland of the Xhosa people is marked by lands in the Eastern Cape from the Gamtoos River up to Umzimkhulu near Natal, bordered by the frontier of an expanding Dutch Cape Colony. Both the Matabele people, Matabele of Western Zimbabwe and the Ngoni people, Ngoni migrated northward out ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bedouin
The Bedouin, Beduin, or Bedu ( ; , singular ) are pastorally nomadic Arab tribes who have historically inhabited the desert regions in the Arabian Peninsula, North Africa, the Levant, and Mesopotamia (Iraq). The Bedouin originated in the Syrian Desert and Arabian Desert but spread across the rest of the Arab world in West Asia and North Africa after the spread of Islam. The English word ''bedouin'' comes from the Arabic ''badawī'', which means "desert-dweller", and is traditionally contrasted with ''ḥāḍir'', the term for sedentary people. Bedouin territory stretches from the vast deserts of North Africa to the rocky ones of the Middle East. They are sometimes traditionally divided into tribes, or clans (known in Arabic as ''ʿašāʾir''; or ''qabāʾil'' ), and historically share a common culture of herding camels, sheep and goats. The vast majority of Bedouins adhere to Islam, although there are some fewer numbers of Christian Bedouins present in the Fertile Cres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fulani
The Fula, Fulani, or Fulɓe people are an ethnic group in Sahara, Sahel and West Africa, widely dispersed across the region. Inhabiting many countries, they live mainly in West Africa and northern parts of Central Africa, South Sudan, Darfur, and regions near the Red Sea coast in Sudan. The approximate number of Fula people is unknown, due to clashing definitions regarding Fula ethnicity. Various estimates put the figure between 25 and 40 million people worldwide. A significant proportion of the Fula – a third, or an estimated 7 to 10 million – are pastoralists, and their ethnic group has the largest nomadic pastoral community in the world., Quote: The Fulani form the largest pastoral nomadic group in the world. The Bororo'en are noted for the size of their cattle herds. In addition to fully nomadic groups, however, there are also semisedentary Fulani – Fulbe Laddi – who also farm, although they argue that they do so out of necessity, not choice. The majority of the Fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
