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Lactic Acid Fermentation
Lactic acid fermentation is a metabolic process by which glucose or other hexose, six-carbon sugars (also, disaccharides of six-carbon sugars, e.g. sucrose or lactose) are converted into cellular energy and the metabolite lactic acid, lactate, which is lactic acid in solution. It is an Anaerobic organism#Metabolism, anaerobic fermentation reaction that occurs in some bacteria and animal cells, such as muscle cells. If oxygen is present in the cell, many organisms will bypass fermentation and undergo cellular respiration; however, facultative anaerobic organisms will both ferment and undergo respiration in the presence of oxygen. Sometimes even when oxygen is present and aerobic metabolism is happening in the mitochondria, if pyruvate is building up faster than it can be metabolized, the fermentation will happen anyway. Lactate dehydrogenase catalyzes the interconversion of pyruvate and lactic acid, lactate with concomitant interconversion of NADH and Nicotinamide adenine dinucle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyruvate
Pyruvic acid (CH3COCOOH) is the simplest of the alpha-keto acids, with a carboxylic acid and a ketone functional group. Pyruvate, the conjugate base, CH3COCOO−, is an intermediate in several metabolic pathways throughout the cell. Pyruvic acid can be made from glucose through glycolysis, converted back to carbohydrates (such as glucose) via gluconeogenesis, or converted to fatty acids through a reaction with acetyl-CoA. It can also be used to construct the amino acid alanine and can be converted into ethanol or lactic acid via fermentation. Pyruvic acid supplies energy to cells through the citric acid cycle (also known as the Krebs cycle) when oxygen is present ( aerobic respiration), and alternatively ferments to produce lactate when oxygen is lacking. Chemistry In 1834, Théophile-Jules Pelouze distilled tartaric acid and isolated glutaric acid and another unknown organic acid. Jöns Jacob Berzelius characterized this other acid the following year and na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Competitive Advantage
In business, a competitive advantage is an attribute that allows an organization to outperform its competitors. A competitive advantage may include access to natural resources, such as high-grade ores or a low-cost power source, highly skilled labor, geographic location, high entry barriers, and access to new technology and to proprietary information. Overview The term ''competitive advantage'' refers to the ability gained through attributes and resources to perform at a higher level than others in the same industry or market (Christensen and Fahey 1984, Kay 1994, Porter 1980 cited by Chacarbaghi and Lynch 1999, p. 45). The study of this advantage has attracted profound research interest due to contemporary issues regarding superior performance levels of firms in today's competitive market. "A firm is said to have a competitive advantage when it is implementing a value creating strategy not simultaneously being implemented by any current or potential player" (Barney 1991 cited ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Babylonia
Babylonia (; , ) was an Ancient history, ancient Akkadian language, Akkadian-speaking state and cultural area based in the city of Babylon in central-southern Mesopotamia (present-day Iraq and parts of Kuwait, Syria and Iran). It emerged as an Akkadian-populated but Amorites, Amorite-ruled state . During the reign of Hammurabi and afterwards, Babylonia was retrospectively called "the country of Akkad" ( in Akkadian), a deliberate archaism in reference to the previous glory of the Akkadian Empire. It was often involved in rivalry with the older ethno-linguistically related state of Assyria in the north of Mesopotamia and Elam to the east in Ancient Iran. Babylonia briefly became the major power in the region after Hammurabi (floruit, fl. –1752 BC middle chronology, or –1654 BC, short chronology timeline, short chronology) created a short-lived empire, succeeding the earlier Akkadian Empire, Third Dynasty of Ur, and Old Assyrian Empire. The Babylonian Empire rapidly fell apar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cuneiform Script
Cuneiform is a Logogram, logo-Syllabary, syllabic writing system that was used to write several languages of the Ancient Near East. The script was in active use from the early Bronze Age until the beginning of the Common Era. Cuneiform scripts are marked by and named for the characteristic wedge-shaped impressions (Latin: ) which form their Grapheme, signs. Cuneiform is the History of writing#Inventions of writing, earliest known writing system and was originally developed to write the Sumerian language of southern Mesopotamia (modern Iraq). Over the course of its history, cuneiform was adapted to write a number of languages in addition to Sumerian. Akkadian language, Akkadian texts are attested from the 24th century BC onward and make up the bulk of the cuneiform record. Akkadian cuneiform was itself adapted to write the Hittite language in the early second millennium BC. The other languages with significant cuneiform Text corpus, corpora are Eblaite language, Eblaite, Elamit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheesemaking
Cheesemaking (or caseiculture) is the craft of making cheese. The production of cheese, like many other food preservation processes, allows the nutritional and economic value of a food material, in this case milk, to be preserved in concentrated form. Cheesemaking allows the production of the cheese with diverse flavors and consistencies. History Cheesemaking is documented in Egyptian tomb drawings and in ancient Greek literature. Cheesemaking may have originated from nomadic herdsmen who stored milk in vessels made from sheep's and goats' stomachs. Because their stomach linings contain a mix of lactic acid, bacteria as milk contaminants and rennet, the milk would ferment and coagulate.Kats, Sandor Ellix; Pollan, Michael (2015). The Art of Fermentation an In-depth Exploration of Essential Concepts and Processes from around the World. Vermont: Chelsea Green Publishing. A product reminiscent of yogurt would have been produced, which through gentle agitation and the separation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Populations
Population is a set of humans or other organisms in a given region or area. Governments conduct a census to quantify the resident population size within a given jurisdiction. The term is also applied to non-human animals, microorganisms, and plants, and has specific uses within such fields as ecology and genetics. Etymology The word ''population'' is derived from the Late Latin ''populatio'' (a people, a multitude), which itself is derived from the Latin word ''populus'' (a people). Use of the term Social sciences In sociology and population geography, population refers to a group of human beings with some predefined feature in common, such as location, race, ethnicity, nationality, or religion. Ecology In ecology, a population is a group of organisms of the same species which inhabit the same geographical area and are capable of interbreeding. The area of a sexual population is the area where interbreeding is possible between any opposite-sex pair within the a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Farmer
A farmer is a person engaged in agriculture, raising living organisms for food or raw materials. The term usually applies to people who do some combination of raising field crops, orchards, vineyards, poultry, or other livestock. A farmer might own the farmland or might work as a laborer on land owned by others. In most developed economies, a "farmer" is usually a farm owner ( landowner), while employees of the farm are known as '' farm workers'' (or farmhands). However, in other older definitions a farmer was a person who promotes or improves the growth of plants, land, or crops or raises animals (as livestock or fish) by labor and attention. Over half a billion farmers are smallholders, most of whom are in developing countries and who economically support almost two billion people. Globally, women constitute more than 40% of agricultural employees. History Farming dates back as far as the Neolithic, being one of the defining characteristics of that era. By the Bronze ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactic Acid Bacteria
Lactobacillales are an order of gram-positive, low-GC, acid-tolerant, generally nonsporulating, nonrespiring, either rod-shaped (bacilli) or spherical ( cocci) bacteria that share common metabolic and physiological characteristics. These bacteria, usually found in decomposing plants and milk products, produce lactic acid as the major metabolic end product of carbohydrate fermentation, giving them the common name lactic acid bacteria (LAB). Production of lactic acid has linked LAB with food fermentations, as acidification inhibits the growth of spoilage agents. Proteinaceous bacteriocins are produced by several LAB strains and provide an additional hurdle for spoilage and pathogenic microorganisms. Furthermore, lactic acid and other metabolic products contribute to the organoleptic and textural profile of a food item. The industrial importance of the LAB is further evidenced by their generally recognized as safe (GRAS) status, due to their ubiquitous appearance in food and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neolithic Revolution
The Neolithic Revolution, also known as the First Agricultural Revolution, was the wide-scale transition of many human cultures during the Neolithic period in Afro-Eurasia from a lifestyle of hunter-gatherer, hunting and gathering to one of agriculture and sedentism, settlement, making an increasingly large population possible. These settled communities permitted humans to observe and experiment with plants, learning how they grew and developed. This new knowledge led to the domestication of plants into crops. Archaeological data indicate that the domestication of various types of plants and animals happened in separate locations worldwide, starting in the Geologic time scale, geological epoch of the Holocene 11,700 years ago, after the end of the last Ice Age. It was humankind's first historically verifiable transition to agriculture. The Neolithic Revolution greatly narrowed the diversity of foods available, resulting in a decrease in the quality of human nutrition compared ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphoketolase
The enzyme phosphoketolase() catalyzes the chemical reactions :D-xylulose 5-phosphate + phosphate \rightleftharpoons acetyl phosphate + D-glyceraldehyde 3-phosphate + H2O () :D-fructose 6-phosphate + phosphate \rightleftharpoons acetyl phosphate + D-erythrose 4-phosphate + H2OEC 4.1.2.22 :D-sedoheptulose 7-phosphate + phosphate \rightleftharpoons acetyl phosphate + D-ribose 5-phosphate + H2O Phosphoketolase is considered a promiscuous enzyme because it was demonstrated to use 3 different sugar phosphates as substrates. In a recent genetic study, more than 150 putative phosphoketolase genes exhibiting varying catalytic properties were found in 650 analyzed bacterial genomes. This enzyme belongs to the family of lyases, specifically the aldehyde-lyases, which cleave carbon-carbon bonds. It participates in 3 metabolic pathways: pentose phosphate pathway, methane metabolism, and carbon fixation. It employs one cofactor, thiamin diphosphate. Phosphoketolase was previously used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
