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Decomposition
Decomposition or rot is the process by which dead organic substances are broken down into simpler organic or inorganic matter such as carbon dioxide, water, simple sugars and mineral salts. The process is a part of the nutrient cycle and is essential for recycling the finite matter that occupies physical space in the biosphere. Bodies of living organisms begin to decompose shortly after death. Animals, such as worms, also help decompose the organic materials. Organisms that do this are known as decomposers or detritivores. Although no two organisms decompose in the same way, they all undergo the same sequential stages of decomposition. The science which studies decomposition is generally referred to as ''taphonomy'' from the Greek word ''taphos'', meaning tomb. Decomposition can also be a gradual process for organisms that have extended periods of dormancy. One can differentiate abiotic decomposition from biotic decomposition (biodegradation). The former means "the degradation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Decomposition
Chemical decomposition, or chemical breakdown, is the process or effect of simplifying a single chemical entity (normal molecule, reaction intermediate, etc.) into two or more fragments. Chemical decomposition is usually regarded and defined as the exact opposite of chemical synthesis. In short, the chemical reaction in which two or more products are formed from a single reactant is called a decomposition reaction. The details of a decomposition process are not always well defined but some of the process is understood; much energy is needed to break bonds. Since all decomposition reactions break apart the bonds holding it together in order to produce into its simpler basic parts, the reactions would require some form of this energy in varying degrees. Because of this fundamental rule, it is known that most of these reactions are endothermic although exceptions do exist. The stability of a chemical compound is eventually limited when exposed to extreme environmental conditions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Death
Death is the irreversible cessation of all biological functions that sustain an organism. For organisms with a brain, death can also be defined as the irreversible cessation of functioning of the whole brain, including brainstem, and brain death is sometimes used as a legal definition of death. The remains of a former organism normally begin to decompose shortly after death. Death is an inevitable process that eventually occurs in almost all organisms. Death is generally applied to whole organisms; the similar process seen in individual components of an organism, such as cells or tissues, is necrosis. Something that is not considered an organism, such as a virus, can be physically destroyed but is not said to die. As of the early 21st century, over 150,000 humans die each day, with ageing being by far the most common cause of death. Many cultures and religions have the idea of an afterlife, and also may hold the idea of judgement of good and bad deeds in one's life ( h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Putrefaction
Putrefaction is the fifth stage of death, following pallor mortis, algor mortis, rigor mortis, and livor mortis. This process references the breaking down of a body of an animal, such as a human, post-mortem. In broad terms, it can be viewed as the decomposition of proteins, and the eventual breakdown of the cohesiveness between tissues, and the liquefaction of most organs. This is caused by the decomposition of organic matter by bacterial or fungal digestion, which causes the release of gases that infiltrate the body's tissues, and leads to the deterioration of the tissues and organs. The approximate time it takes putrefaction to occur is dependent on various factors. Internal factors that affect the rate of putrefaction include the age at which death has occurred, the overall structure and condition of the body, the cause of death, and external injuries arising before or after death. External factors include environmental temperature, moisture and air exposure, clothing, bur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biodegradation
Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegradation occurs under a specific set of circumstances. The process of biodegradation is threefold: first an object undergoes biodeterioration, which is the mechanical weakening of its structure; then follows biofragmentation, which is the breakdown of materials by microorganisms; and finally assimilation, which is the incorporation of the old material into new cells. In practice, almost all chemical compounds and materials are subject to biodegradation, the key element being time. Things like vegetables may degrade within days, while glass and some plastics take many millennia to decompose. A standard for biodegradability used by the European Union is that greater than 90% of the original material must be converted into , water and minerals b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blow-fly
The Calliphoridae (commonly known as blow flies, blow-flies, carrion flies, bluebottles, greenbottles, or cluster flies) are a family of insects in the order Diptera, with almost 1,900 known species. The maggot larvae, often used as fishing bait, are known as gentles. The family is known to be polyphyletic, but much remains disputed regarding proper treatment of the constituent taxa, some of which are occasionally accorded family status (e.g., Bengaliidae and Helicoboscidae). The name blowfly comes from an older English term for meat that had eggs laid on it, which was said to be flyblown. The first known association of the term "blow" with flies appears in the plays of William Shakespeare: '' Love's Labour's Lost'', '' The Tempest'', and '' Antony and Cleopatra''. Description Characteristics Calliphoridae adults are commonly shiny with metallic colouring, often with blue, green, or black thoraces and abdomens. Antennae are three-segmented and aristate. The aristae are p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic relationsh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cadaverine
Cadaverine is an organic compound with the formula (CH2)5(NH2)2. Classified as diamine, it is a colorless liquid with an unpleasant odor. It is present in small quantities in living organisms but is often associated with the putrefaction of animal tissue. Production Cadaverine is produced by decarboxylation of lysine.Wolfgang Legrum: ''Riechstoffe, zwischen Gestank und Duft'', Vieweg + Teubner Verlag (2011) S. 65, It can be synthesized by many methods including the hydrogenation of glutaronitrile and the reactions of 1,5-dichloropentane. History Putrescine and cadaverine were first described in 1885 by the Berlin physician Ludwig Brieger (1849–1919). Receptors In zebrafish, the trace amine-associated receptor 13c (or TAAR13c) has been identified as a high-affinity receptor for cadaverine. In humans, molecular modelling and docking experiments have shown that cadaverine fits into the binding pocket of the human TAAR6 and TAAR8. Clinical significance Elevated levels of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Putrescine
Putrescine is an organic compound with the formula (CH2)4(NH2)2. It is a colorless solid that melts near room temperature. It is classified as a diamine. Together with cadaverine, it is largely responsible for the foul odor of putrefying flesh, but also contributes to other unpleasant odors. Production Putrescine is produced on an industrial scale by the hydrogenation of succinonitrile. Biotechnological production of putrescine from renewable feedstock has been investigated. A metabolically engineered strain of ''Escherichia coli'' that produces putrescine at high concentrations in glucose mineral salts medium has been described. Biochemistry Spermidine synthase uses putrescine and ''S''-adenosylmethioninamine (decarboxylated ''S''-adenosyl methionine) to produce spermidine. Spermidine in turn is combined with another ''S''-adenosylmethioninamine and gets converted to spermine. Putrescine is synthesized in small quantities by healthy living cells by the action of ornithine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Odor
An odor (American English) or odour (English in the Commonwealth of Nations, Commonwealth English; American and British English spelling differences#-our, -or, see spelling differences) is caused by one or more volatilized chemical compounds that are generally found in low concentrations that humans and animals can perceive via their sense of Sense of smell, smell. An odor is also called a "smell" or a "scent", which can refer to either a pleasant or an unpleasant odor. While "odor" and "smell" can refer to pleasant and unpleasant odors, the terms "scent", "aroma", and "fragrance" are usually reserved for pleasant-smelling odors and are frequently used in the food and cosmetic industry to describe floral scents or to refer to perfumes. Physiology of smell Sense of smell The perception of odors, or sense of smell, is mediated by the olfactory nerve. The olfactory receptor (OR) cells are neurons present in the olfactory epithelium, which is a small patch of tissue at th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tissue (biology)
In biology, tissue is a biological organizational level between cells and a complete organ. A tissue is an ensemble of similar cells and their extracellular matrix from the same origin that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues. The English word "tissue" derives from the French word "tissu", the past participle of the verb tisser, "to weave". The study of tissues is known as histology or, in connection with disease, as histopathology. Xavier Bichat is considered as the "Father of Histology". Plant histology is studied in both plant anatomy and physiology. The classical tools for studying tissues are the paraffin block in which tissue is embedded and then sectioned, the histological stain, and the optical microscope. Developments in electron microscopy, immunofluorescence, and the use of frozen tissue-sections have enhanced the detail that can be observed in tissues. With these tools, the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungi
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from the other eukaryotic kingdoms, which by one traditional classification include Plantae, Animalia, Protozoa, and Chromista. A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related organisms, named the ''Eumycota'' (''t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scavenger
Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding behavior. Scavengers play an important role in the ecosystem by consuming dead animal and plant material. ''Decomposers'' and detritivores complete this process, by consuming the remains left by scavengers. Scavengers aid in overcoming fluctuations of food resources in the environment. The process and rate of scavenging is affected by both biotic and abiotic factors, such as carcass size, habitat, temperature, and seasons. Etymology Scavenger is an alteration of ''scavager,'' from Middle English ''skawager'' meaning "customs collector", from ''skawage'' meaning "customs", from Old North French ''escauwage'' meaning "inspection", from ''schauwer'' meaning "to inspect", of Germanic origin; akin to Old English ''scēawian'' and German ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
