where does the human chemical digestion of carbohydrates end
stomach
1430952
benefits: it denatures proteins for further digestion in the small intestines, and provides non-specific immunity, damaging or eliminating various pathogens. In the small intestines, the duodenum provides critical pH balancing to activate digestive enzymes. The liver secretes bile into the duodenum to neutralize the acidic conditions from the stomach, and the pancreatic duct empties into the duodenum, adding bicarbonate to neutralize the acidic chyme, thus creating a neutral environment. The mucosal tissue of the small intestines is alkaline with a pH of about 8.5. Digestion Digestion is the breakdown of large insoluble food molecules into small water-soluble food molecules so
Digestion
1430940
cephalic phase in which saliva is produced in the mouth and digestive enzymes are produced in the stomach. Mechanical and chemical digestion begin in the mouth where food is chewed, and mixed with saliva to begin enzymatic processing of starches. The stomach continues to break food down mechanically and chemically through churning and mixing with both acids and enzymes. Absorption occurs in the stomach and gastrointestinal tract, and the process finishes with defecation. The human gastrointestinal tract is around 9 meters long. Food digestion physiology varies between individuals and upon other factors such as the characteristics of the food and
Digestion
8291569
intestinal wall. In the epithelial cells, fatty acids are packaged and transported to the rest of the body. Digestion is the first step to lipid metabolism, and it is the process of breaking the triglycerides down into smaller monoglyceride units with the help of lipase enzymes. Digestion of fats begin in the mouth through chemical digestion by lingual lipase. Ingested cholesterol is not broken down by the lipases and stays intact until it enters the epithelium cells of small intestine. Lipids then continue to the stomach where chemical digestion continues by gastric lipase and mechanical digestion begins (Peristalsis). The majority
Lipid metabolism
1430951
(largely the glucose-insulin system) have been uncovered in recent years. Digestion is a complex process controlled by several factors. pH plays a crucial role in a normally functioning digestive tract. In the mouth, pharynx and esophagus, pH is typically about 6.8, very weakly acidic. Saliva controls pH in this region of the digestive tract. Salivary amylase is contained in saliva and starts the breakdown of carbohydrates into monosaccharides. Most digestive enzymes are sensitive to pH and will denature in a high or low pH environment. The stomach's high acidity inhibits the breakdown of carbohydrates within it. This acidity confers two
Digestion
2668655
fiber, one of three types of dietary fiber including soluble, insoluble, and resistant starch. Soluble fiber dissolves in water to form a gelatinous material. Some soluble fibers may help lower blood cholesterol and glucose levels. Because normal digestion does not break inulin down into monosaccharides, it does not elevate blood sugar levels and may, therefore, be helpful in the management of diabetes. Inulin also stimulates the growth of bacteria in the gut. Inulin passes through the stomach and duodenum undigested and is highly available to the gut bacterial flora. This makes it similar to resistant starches and other fermentable carbohydrates.
Inulin
8548556
Protein (nutrient) Proteins are essential nutrients for the human body. They are one of the building blocks of body tissue and can also serve as a fuel source. As a fuel, proteins provide as much energy density as carbohydrates: 4 kcal (17 kJ) per gram; in contrast, lipids provide 9 kcal (37 kJ) per gram. The most important aspect and defining characteristic of protein from a nutritional standpoint is its amino acid composition. Proteins are polymer chains made of amino acids linked together by peptide bonds. During human digestion, proteins are broken down in the stomach to smaller polypeptide chains
Protein (nutrient)
783703
the pyloric sphincter of the stomach to the anus and, as in other mammals, consists of two segments, the small intestine and the large intestine. In humans, the small intestine is further subdivided into the duodenum, jejunum and ileum while the large intestine is subdivided into the, cecum, ascending, transverse, descending and sigmoid colon, rectum, and anal canal. The small intestine begins at the duodenum and is a tubular structure, usually between 6 and 7 m long. Its mucosal area in an adult human is about 30 m. Its main function is to absorb the products of digestion (including carbohydrates,
Gastrointestinal tract
3726907
around it instead of having a "complete task at all costs" mentality. Gastrobot Gastrobot, meaning literally 'stomach robot', was a term coined in 1998 by the University of South Florida Institute's director, Dr. Stuart Wilkinson. A gastrobot is "...an intelligent machine (robot) that derives all its energy requirements from the digestion of real food." The gastrobot's energy intake may come in the form of carbohydrates, lipids etc., or may be a simpler source, such as alcohol. The energy source commonly used for this robot is a mixture of carbohydrates and protein. The robot gets these molecules through a microbial fuel
Gastrobot
3726902
Gastrobot Gastrobot, meaning literally 'stomach robot', was a term coined in 1998 by the University of South Florida Institute's director, Dr. Stuart Wilkinson. A gastrobot is "...an intelligent machine (robot) that derives all its energy requirements from the digestion of real food." The gastrobot's energy intake may come in the form of carbohydrates, lipids etc., or may be a simpler source, such as alcohol. The energy source commonly used for this robot is a mixture of carbohydrates and protein. The robot gets these molecules through a microbial fuel cell (MFC), which converts the food into gases and other potential energy.
Gastrobot
94928
the digestion of cellulose and also produce certain B vitamins. After excretion of the soft cecotrope, it is again eaten whole by the animal and redigested in a special part of the stomach. The pellets remain intact for up to six hours in the stomach; the bacteria within continue to digest the plant carbohydrates. This double-digestion process enables these animals to use nutrients that they may have missed during the first passage through the gut, as well as the nutrients formed by the microbial activity and thus ensures that maximum nutrients are derived from the food they eat. This process
Coprophagia
356475
that help with the digestion of cellulose and also produce certain B vitamins. The pellets are about 56% bacteria by dry weight, largely accounting for the pellets being 24.4% protein on average. The soft feces form here and contain up to five times the vitamins of hard feces. After being excreted, they are eaten whole by the rabbit and redigested in a special part of the stomach. The pellets remain intact for up to six hours in the stomach; the bacteria within continue to digest the plant carbohydrates. This double-digestion process enables rabbits to use nutrients that they may have
Rabbit
967817
the gallbladder enter the small intestine in response to the hormone cholecystokinin, which is produced in the small intestine in response to the presence of nutrients. Secretin, another hormone produced in the small intestine, causes additional effects on the pancreas, where it promotes the release of bicarbonate into the duodenum in order to neutralize the potentially harmful acid coming from the stomach. The three major classes of nutrients that undergo digestion are proteins, lipids (fats) and carbohydrates: Digested food is now able to pass into the blood vessels in the wall of the intestine through either diffusion or active transport.
Small intestine
1430938
gizzard add enzymes to the thick paste, which helps chemically breakdown the organic matter. By peristalsis, the mixture is sent to the intestine where friendly bacteria continue chemical breakdown. This releases carbohydrates, protein, fat, and various vitamins and minerals for absorption into the body. In most vertebrates, digestion is a multistage process in the digestive system, starting from ingestion of raw materials, most often other organisms. Ingestion usually involves some type of mechanical and chemical processing. Digestion is separated into four steps: Underlying the process is muscle movement throughout the system through swallowing and peristalsis. Each step in digestion requires
Digestion
73475
whole food, where fiber, vitamins and minerals are also found (as opposed to processed carbohydrates, which provide energy but few other nutrients). The standard usage, however, is to classify carbohydrates chemically: simple if they are sugars (monosaccharides and disaccharides) and complex if they are polysaccharides (or oligosaccharides). In any case, the simple vs. complex chemical distinction has little value for determining the nutritional quality of carbohydrates. Some simple carbohydrates (e.g. fructose) raise blood glucose slowly, while some complex carbohydrates (starches), especially if processed, raise blood sugar rapidly. The speed of digestion is determined by a variety of factors including which
Carbohydrate
935183
or during periods of starvation. Carbohydrates may be classified as monosaccharides, disaccharides or polysaccharides depending on the number of monomer (sugar) units they contain. They are a diverse group of substances, with a range of chemical, physical and physiological properties. They make up a large part of foods such as rice, noodles, bread, and other grain-based products, but they are not an essential nutrient, meaning a human does not need to eat carbohydrates. Monosaccharides contain one sugar unit, disaccharides two, and polysaccharides three or more. Monosaccharides include glucose, fructose and galactose. Disaccharides include sucrose, lactose, and maltose; purified sucrose, for
Human nutrition
18260447
host may have genes that can determine the efficiency of digestion and absorption of carbohydrates in the small intestine. For example, lactose is accessible to the microbiota in people who are lactose intolerant, and should therefore be considered a MAC for those individuals. For nursing infants, dietary MACs that are naturally found in breast milk are known as human milk oligosaccharides (HMOs). For formula-fed infants, dietary MACs, such as galacto-oligosaccharides, are artificially added to formula. Therefore the research, discussion and quantification of MACs and their impact on a host's microbiota may be critical to determining their impact on human health.
Microbiota-accessible carbohydrates
14614241
their corresponding monosaccharides by enzymes (maltase, isomaltase, sucrase and lactase) present in the brush border of the small intestine. In the typical Western diet, digestion and absorption of carbohydrates is fast and takes place usually in the upper small intestine. However, when the diet contains carbohydrates not easily digestible, digestion and absorption take place mainly in the ileal portion of the intestine. Digestion of food continues while simplest elements are absorbed. The absorption of most digested food occurs in the small intestine through the brush border of the epithelium covering the villi (small hair-like structure). It is not a simple
Carbohydrate digestion
278140
Metabolism Metabolism (, from "metabolē", "change") is the set of life-sustaining chemical reactions in organisms. The three main purposes of metabolism are: the conversion of food/fuel to energy to run cellular processes; the conversion of food/fuel to building blocks for proteins, lipids, nucleic acids, and some carbohydrates; and the elimination of nitrogenous wastes. These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their structures, and respond to their environments. (The word metabolism can also refer to the sum of all chemical reactions that occur in living organisms, including digestion and the transport of substances into and between different cells,
Metabolism
18451847
that does not involve the use of pili or flagella. The bacterium is positive for gelatin hydrolysis, albumin digestion, tributyrin digestion, tributyrin hydrolysis, "E.coli" cell autolysis, and casein hydrolysis. On its fish host, the pathogen can be found on external and internal sites such as skin/mucus, gills, brain, ascites, lesions, mucus, kidney, spleen, and reproductive excretions of spawning adults. Colonization is evident by faint, white areas on the host. "Flavobacterium psychrophilum" has a strictly aerobic metabolism, but is unable to use carbohydrates as a source of carbon and energy. Instead, it relies on peptides for carbon and energy. Secreted proteases
Flavobacterium psychrophilum
760839
benefits (i.e., resistant starch increases bulking, increases colonic fermentation, positively modulates colonic microflora and increases satiety and insulin sensitivity). The beneficial effects of high fiber diets are the summation of the effects of the different types of fiber present in the diet and also other components of such diets. Defining fiber physiologically allows recognition of indigestible carbohydrates with structures and physiological properties similar to those of naturally occurring dietary fibers. The American Association of Cereal Chemists has defined soluble fiber this way: ""the edible parts of plants or similar carbohydrates resistant to digestion and absorption in the human small intestine
Dietary fiber
17916264
role in the body's metabolism. The liver has many functions some of which are important to digestion. The liver can detoxify various metabolites; synthesise proteins and produce biochemicals needed for digestion. It regulates the storage of glycogen which it can form from glucose (glycogenesis). The liver can also synthesise glucose from certain amino acids. Its digestive functions are largely involved with the breaking down of carbohydrates. It also maintains protein metabolism in its synthesis and degradation. In lipid metabolism it synthesises cholesterol. Fats are also produced in the process of lipogenesis. The liver synthesises the bulk of lipoproteins. The liver
Human digestive system
16143755
GI. Consumption of IMO effectively improved bowel movements, stool output and microbial fermentation in the colon without any adverse effects in elderly people. The American Association of Cereal Chemists (AACC) defines soluble fiber as "the edible parts of plants or similar carbohydrates resistant to digestion and absorption in the human small intestine with complete or partial fermentation in the large intestine". Dietary fiber consists of many plant components including oligosaccharides. For a dietary substrate to be classified as a fiber, it must be resistant to digestion and absorption in upper GI tract, and cause a bulking effect in defecation. IMO
Isomaltooligosaccharide
490482
cleaved, creating a cascade of activating enzymes: enteropeptidase activates the proenzyme trypsinogen by cleaving it to form trypsin. The free trypsin then cleaves the rest of the trypsinogen, as well as chymotrypsinogen to its active form chymotrypsin. The pancreas secretes substances which help in the digestion of starch and other carbohydrates, proteins and fats. Proteases, the enzymes involved in the digestion of proteins, include trypsinogen and chymotrypsinogen. The enzyme involved in the digestion of fats is lipase. Amylase, also secreted by the pancreas, breaks down starch (amylum) and other carbohydrates. The pancreas also secretes phospholipase A2, lysophospholipase, and cholesterol esterase.
Pancreas
2437110
hours or longer after eating certain foods. Foods with carbohydrates that break down quickly during digestion and release glucose rapidly into the bloodstream tend to have a high GI; foods with carbohydrates that break down more slowly, releasing glucose more gradually into the bloodstream, tend to have a low GI. The concept was developed by Dr. David J. Jenkins and colleagues in 1980–1981 at the University of Toronto in their research to find out which foods were best for people with diabetes. A lower glycemic index suggests slower rates of digestion and absorption of the foods' carbohydrates and can also
Glycemic index
2958700
membrane into the lacteals, where they join lymph to become chyle. The lymphatic vessels carry the chyle to the venous return of the systemic circulation. From there the chylomicrons supply the tissue with fat absorbed from the diet. Thus, unlike the saccharides and amino acids that digestion liberates from the carbohydrates and proteins of the diet (respectively), the lipids from the diet bypass the hepatic portal system, meaning the liver does not get "first crack" at them. There are three stages in the chylomicron's "lifecycle": Triglycerides are emulsified by bile and hydrolyzed by the enzyme lipase, resulting in a mixture
Chylomicron
8968667
Miglitol Miglitol is an oral anti-diabetic drug that acts by inhibiting the ability of the patient to break down complex carbohydrates into glucose. It is primarily used in diabetes mellitus type 2 for establishing greater glycemic control by preventing the digestion of carbohydrates (such as disaccharides, oligosaccharides, and polysaccharides) into monosaccharides which can be absorbed by the body. Miglitol, and other structurally-related iminosugars, inhibit glycoside hydrolase enzymes called alpha-glucosidases. Since miglitol works by preventing digestion of carbohydrates, it lowers the degree of postprandial hyperglycemia. It must be taken at the start of main meals to have maximal effect. Its effect
Miglitol
16143748
Isomaltooligosaccharide Isomaltooligosaccharide (IMO) is a mixture of short-chain carbohydrates which has a digestion-resistant property. IMO is found naturally in some foods, as well as being manufactured commercially. The raw material used for manufacturing IMO is starch, which is enzymatically converted into a mixture of isomaltooligosaccharides. The term "oligosaccharide" encompasses carbohydrates that are larger than simple di- or tri-saccharides, but smaller than polysaccharides (greater than 10 units). Isomalto-oligosaccharides (IMO) are glucose oligomers with α-D-(1,6)-linkages, including isomaltose, panose, isomaltotriose, isomaltotetraose, isomaltopentaose, nigerose, kojibiose, and higher branched oligosaccharides. While human intestinal enzymes readily digest α(1,4)-glycosidic bonds, α(1,6)-linkages are not easily hydrolyzed and exhibit
Isomaltooligosaccharide
1394805
human digestion, pectin binds to cholesterol in the gastrointestinal tract and slows glucose absorption by trapping carbohydrates. Pectin is thus a soluble dietary fiber. In non-obese diabetic (NOD) mice pectin has been shown to increase the incidence of diabetes. A study found that after consumption of fruit the concentration of methanol in the human body increased by as much as an order of magnitude due to the degradation of natural pectin (which is esterified with methyl alcohol) in the colon). Pectin has been observed to have some function in DNA repair of plants. Pectinaceous surface pellicles, which are rich in
Pectin
2356887
Carbohydrate metabolism Various biochemical processes responsible for the metabolic formation, breakdown, and interconversion of carbohydrates in living organisms. Carbohydrates are central to many essential metabolic pathways. Plants synthesize carbohydrates from carbon dioxide and water through photosynthesis, allowing them to store energy absorbed from sunlight internally. When animals and fungi consume plants, they use cellular respiration to break down these stored carbohydrates to make energy available to cells. Both animals and plants temporarily store the released energy in the form of high energy molecules, such as ATP, for use in various cellular processes. Although humans consume a variety of carbohydrates, digestion
Carbohydrate metabolism
104302
sometimes crystalline, sometimes water-soluble, and sometimes sweet-tasting and sticky-feeling. Digestion involves breakdown to the monosaccharides. Maltose, cellobiose, and chitobiose are hydrolysis products of the polysaccharides starch, cellulose, and chitin, respectively. Less common disaccharides include: Disaccharide A disaccharide (also called a double sugar or bivose) is the sugar formed when two monosaccharides (simple sugars) are joined by glycosidic linkage. Like monosaccharides, disaccharides are soluble in water. Three common examples are sucrose, lactose, and maltose. Disaccharides are one of the four chemical groupings of carbohydrates (monosaccharides, disaccharides, oligosaccharides, and polysaccharides). The most common types of disaccharides—sucrose, lactose, and maltose—have twelve carbon atoms,
Disaccharide
4016766
intestine, whereas the membrane-bound intestinal alpha-glucosidases hydrolyze oligosaccharides, trisaccharides, and disaccharides to glucose and other monosaccharides in the small intestine. Inhibition of these enzyme systems reduces the rate of digestion of complex carbohydrates. Less glucose is absorbed because the carbohydrates are not broken down into glucose molecules. In diabetic patients, the short-term effect of these drug therapies is to decrease current blood glucose levels; the long-term effect is a reduction in HbA level. This reduction averages an absolute decrease of 0.7%, which is a decrease of about 10% in typical HbA values in diabetes studies. Since acarbose prevents the digestion
Acarbose
8150202
inhibitor suffers from an episode of hypoglycemia, the patient should eat something containing monosaccharides, such as glucose tablets. Since the drug will prevent the digestion of polysaccharides (or non-monosaccharides), non-monosaccharide foods may not effectively reverse a hypoglycemic episode in a patient taking an alpha-glucosidase inhibitor. Alpha-glucosidase inhibitor Alpha-glucosidase inhibitors are oral anti-diabetic drugs used for diabetes mellitus type 2 that work by preventing the digestion of carbohydrates (such as starch and table sugar). Carbohydrates are normally converted into simple sugars (monosaccharides) by alpha-glucosidase enzymes present on cells lining the intestine, enabling monosaccharides to be absorbed through the intestine. Hence, alpha-glucosidase
Alpha-glucosidase inhibitor
2356900
much more compact form of energy storage than hydrophilic carbohydrates. However, animals, including humans, lack the necessary enzymatic machinery and so do not synthesize glucose from lipids (with a few exceptions, e.g. glycerol). In some animals (such as termites) and some microorganisms (such as protists and bacteria), cellulose can be disassembled during digestion and absorbed as glucose. Carbohydrate metabolism Various biochemical processes responsible for the metabolic formation, breakdown, and interconversion of carbohydrates in living organisms. Carbohydrates are central to many essential metabolic pathways. Plants synthesize carbohydrates from carbon dioxide and water through photosynthesis, allowing them to store energy absorbed from
Carbohydrate metabolism
14614240
Carbohydrate digestion All carbohydrates absorbed in the small intestine must be hydrolyzed to monosaccharides prior to absorption. Hydrolysis precedes transport of monosaccharides in hamster intestine. From sucrose, glucose is taken up much faster than fructose. Monosaccharide transport saturates with -glucose at 30 mM. Digestion of starch begins with the action of salivary alpha-amylase/ptyalin, although its activity is slight in comparison with that of pancreatic amylase in the small intestine. Amylase hydrolyzes starch to alpha-dextrin, which are then digested by gluco-amylase (alpha-dextrinases) to maltose and maltotriose. The products of digestion of alpha-amylase and alpha-dextrinase, along with dietary disaccharides are hydrolyzed to
Carbohydrate digestion
18260449
gordonii"), Clostridiales ("Ruminococcus gnavus", "Blautia producta", "Faecalibacterium prausnitzii") and Verrucomicrobiales ("Akkermansia muciniphila"). Introduction of dietary MACs in the diet is insufficient to regain the lost taxa, to restore the gut microbiota to its original state requires the administration of missing taxa ,which can be achieved either by administering probiotics (food) or live biotherapeutics (drugs), in combination with dietary MAC consumption. Enriching the food supply with dietary fiber might have an essential role in preventing loss of certain beneficial bacterial species. Microbiota-accessible carbohydrates Microbiota-accessible carbohydrates (MACs) are carbohydrates that are resistant to digestion by a host's metabolism, and are made available
Microbiota-accessible carbohydrates
18260444
Microbiota-accessible carbohydrates Microbiota-accessible carbohydrates (MACs) are carbohydrates that are resistant to digestion by a host's metabolism, and are made available for gut microbes, as prebiotics, to ferment or metabolize into beneficial compounds, such as short chain fatty acids. The term, ‘‘microbiota-accessible carbohydrate’’ contributes to a conceptual framework for investigating and discussing the amount of metabolic activity that a specific food or carbohydrate can contribute to a host's microbiota. MACs may come from plants, fungi, animal tissues, or food-borne microbes, and must be metabolized by the microbiome. A significant quantity of the cellulose humans consume is not metabolized by gut microbes
Microbiota-accessible carbohydrates
1430915
Digestion Digestion is the breakdown of large insoluble food molecules into small water-soluble food molecules so that they can be absorbed into the watery blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the blood stream. Digestion is a form of catabolism that is often divided into two processes based on how food is broken down: mechanical and chemical digestion. The term mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes. In chemical digestion, enzymes break down food into the
Digestion
73458
includes many biological carbohydrates which deviate from this formula. For example, while the above representative formulas would seem to capture the commonly known carbohydrates, ubiquitous and abundant carbohydrates often deviate from this. For example, carbohydrates often display chemical groups such as: "N"-acetyl (e.g. chitin), sulphate (e.g. glycosaminoglycans), carboxylic acid (e.g. sialic acid) and deoxy modifications (e.g. fucose and sialic acid). Natural saccharides are generally built of simple carbohydrates called monosaccharides with general formula (CHO) where "n" is three or more. A typical monosaccharide has the structure H–(CHOH)(C=O)–(CHOH)–H, that is, an aldehyde or ketone with many hydroxyl groups added, usually one
Carbohydrate
17916241
moistens and softens food, and along with the chewing action of the teeth, transforms the food into a smooth bolus. The bolus is further helped by the lubrication provided by the saliva in its passage from the mouth into the esophagus. Also of importance is the presence in saliva of the digestive enzymes amylase and lipase. Amylase starts to work on the starch in carbohydrates, breaking it down into the simple sugars of maltose and dextrose that can be further broken down in the small intestine. Saliva in the mouth can account for 30% of this initial starch digestion. Lipase
Human digestive system
5050865
tolerance test nor a breakfast test is effective; instead, a hyperglucidic breakfast test or ambulatory glucose testing is the current standard. The body requires a relatively constant input of glucose, a sugar produced upon digestion of carbohydrates, for normal functioning. Glucagon and insulin are among the hormones that ensure a normal range of glucose in the human body. Upon consumption of a meal, blood sugar normally rises, which triggers pancreatic cells to produce insulin. This hormone initiates the absorption of the just-digested blood glucose as glycogen into the liver for metabolism or storage, thereby lowering glucose levels in the blood.
Reactive hypoglycemia
935185
to more cardiovascular disease. The degree of causation is still not clear. Simple carbohydrates are absorbed quickly, and therefore raise blood-sugar levels more rapidly than other nutrients. However, the most important plant carbohydrate nutrient, starch, varies in its absorption. Gelatinized starch (starch heated for a few minutes in the presence of water) is far more digestible than plain starch, and starch which has been divided into fine particles is also more absorbable during digestion. The increased effort and decreased availability reduces the available energy from starchy foods substantially and can be seen experimentally in rats and anecdotally in humans. Additionally,
Human nutrition
6393044
uppermost area of the rumen, the headspace, is filled with gases (such as methane, carbon dioxide, and, to a much lower degree, hydrogen) released from fermentation and anaerobic respiration of food. These gases are regularly expelled from the reticulorumen through the mouth, in a process called eructation. Digestion in the reticulorumen is a complex process. Digestion occurs through fermentation by microbes in the reticulorumen rather than the animal "per se". The reticulorumen is one of the few organs present in animals in which digestion of cellulose and other recalcitrant carbohydrates can proceed to any appreciable degree. The main substrates of
Rumen
7328884
instead or together. Isomaltulose is an available carbohydrate like sucrose and most others sugars or maltodextrins. Available or “nutritive” carbohydrates serve the body as a source of energy for its physiological functions. Whether a carbohydrate becomes available to the body largely depends on its digestion, absorption, and metabolism, When present in foods and beverages that are ingested by humans, isomaltulose is digested completely and absorbed. Its intestinal digestion involves the enzyme isomaltase, which is located at the surface of the brush border lining the inner wall of the small intestine. This enzyme is otherwise involved in the digestion of α-1,6
Isomaltulose
2796487
top in the Zig-Zag model must be turned around and oriented as towards your view. However this does not alter the Fischer projections for any previous carbons. According to IUPAC rules, all hydrogen atoms should preferably be drawn explicitly; in particular, the hydrogen atoms of the end group of carbohydrates should be present. Fischer projections are most commonly used in biochemistry and organic chemistry to represent monosaccharides. They can also be used for amino acids or for other organic molecules, although this is discouraged by the 2006 IUPAC recommendations. Haworth projections are a related chemical notation used to represent sugars
Fischer projection
2616820
by the mainstream medical community as being dangerous and misleading, thereby limiting its appeal at the time. The concept of the glycemic index was developed in 1981 by David Jenkins to account for variances in speed of digestion of different types of carbohydrates. This concept classifies foods according to the rapidity of their effect on blood sugar levelswith fast-digesting simple carbohydrates causing a sharper increase and slower-digesting complex carbohydrates, such as whole grains, a slower one. In the 1990s, Atkins published an update from his 1972 book, "Dr. Atkins New Diet Revolution", and other doctors began to publish books based
Low-carbohydrate diet
8150197
Alpha-glucosidase inhibitor Alpha-glucosidase inhibitors are oral anti-diabetic drugs used for diabetes mellitus type 2 that work by preventing the digestion of carbohydrates (such as starch and table sugar). Carbohydrates are normally converted into simple sugars (monosaccharides) by alpha-glucosidase enzymes present on cells lining the intestine, enabling monosaccharides to be absorbed through the intestine. Hence, alpha-glucosidase inhibitors reduce the impact of dietary carbohydrates on blood sugar. Examples of alpha-glucosidase inhibitors include: Even though the drugs have a similar mechanism of action, there are subtle differences between acarbose and miglitol. Acarbose is an oligosaccharide, whereas miglitol resembles a monosaccharide. Miglitol is fairly
Alpha-glucosidase inhibitor
8968668
will depend on the amount of non-monosaccharide carbohydrates in a person's diet. In contrast to acarbose (another alpha-glucosidase inhibitor), miglitol is systemically absorbed; however, it is not metabolized and is excreted by the kidneys. Miglitol Miglitol is an oral anti-diabetic drug that acts by inhibiting the ability of the patient to break down complex carbohydrates into glucose. It is primarily used in diabetes mellitus type 2 for establishing greater glycemic control by preventing the digestion of carbohydrates (such as disaccharides, oligosaccharides, and polysaccharides) into monosaccharides which can be absorbed by the body. Miglitol, and other structurally-related iminosugars, inhibit glycoside hydrolase
Miglitol
5886192
the digestive tract or subjected to physical fragmentation. This fragmentation may occur through the chewing action of teeth (in the mouth of many vertebrates) or the grinding action of pebbles (in the gizzard of earthworms and birds). Chemical digestion then occurs, breaking down the larger food molecules of polysaccharides and disaccharides, fats, and proteins into their smallest sub-units. Chemical digestion involves hydrolysis reactions that liberate the sub unit molecules—primarily monosaccharides, amino acids and fatty acids—from the food. These products of chemical digestion pass through the epithelial lining of the gut into the blood, in a process known as absorption. Any
Extracellular digestion
4526630
many biosynthetic pathways, including the lignin in wood. Dietary pentose sugars derived from the digestion of nucleic acids may be metabolized through the pentose phosphate pathway, and the carbon skeletons of dietary carbohydrates may be converted into glycolytic/gluconeogenic intermediates. In mammals, the PPP occurs exclusively in the cytoplasm, and is found to be most active in the liver, mammary gland and adrenal cortex in the human. The PPP is one of the three main ways the body creates molecules with reducing power, accounting for approximately 60% of NADPH production in humans. One of the uses of NADPH in the cell
Pentose phosphate pathway
73452
sugars, starch, and cellulose. The saccharides are divided into four chemical groups: monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Monosaccharides and disaccharides, the smallest (lower molecular weight) carbohydrates, are commonly referred to as sugars. The word "saccharide" comes from the Greek word "σάκχαρον" ("sákkharon"), meaning "sugar". While the scientific nomenclature of carbohydrates is complex, the names of the monosaccharides and disaccharides very often end in the suffix -ose, as in the monosaccharides fructose (fruit sugar) and glucose (starch sugar) and the disaccharides sucrose (cane or beet sugar) and lactose (milk sugar). Carbohydrates perform numerous roles in living organisms. Polysaccharides serve for the
Carbohydrate
2838559
Dextrin Dextrins are a group of low-molecular-weight carbohydrates produced by the hydrolysis of starch or glycogen. Dextrins are mixtures of polymers of D-glucose units linked by α-(1→4) or α-(1→6) glycosidic bonds. Dextrins can be produced from starch using enzymes like amylases, as during digestion in the human body and during malting and mashing, or by applying dry heat under acidic conditions (pyrolysis or roasting). The latter process is used industrially, and also occurs on the surface of bread during the baking process, contributing to flavor, color and crispness. Dextrins produced by heat are also known as pyrodextrins. The starch hydrolyses
Dextrin
3487649
in the mountains at Horton Plains National Park or in the rainforest near the city of Galle. The purple-faced langur is mostly folivorous, but will also feed on fruits, flowers, and seeds. While they normally avoid human habitations, fruit such as jak ("Artocarpus heterophyllus"), rambutan ("Nephelium lappaceum"), banana ("Musa balbisiana"), and mango ("Mangifera indica") may contribute up to 50% to their diet in cultivated areas. In the wild, food such as the fruits of "Dimocarpus longan" and "Drypetes sepiaria" are taken. Purple-faced langur digestion is adapted to derive the majority of required nutrients and energy from complex carbohydrates found in
Purple-faced langur
6393045
digestion in the reticulorumen are non-structural carbohydrates (starch, sugar, and pectin), structural carbohydrates (hemicellulose and cellulose), and nitrogen-containing compounds (proteins, peptides, and amino acids). Both non-structural and structural carbohydrates are hydrolysed to monosaccharides or disaccharides by microbial enzymes. The resulting mono- and disaccharides are transported into the microbes. Once within microbial cell walls, the mono- and disaccharides may be assimilated into microbial biomass or fermented to volatile fatty acids (VFAs) acetate, propionate, butyrate, lactate, valerate and other branched-chain VFAs via glycolysis and other biochemical pathways to yield energy for the microbial cell. Most VFAs are absorbed across the reticulorumen wall,
Rumen
12650992
human body obtains the majority of its energy through the citric acid cycle, which can use any of the macronutrients to generate adenosine triphosphate (ATP) used to transport chemical energy within cells. The chemical processes involved use energy themselves, so variations in the efficiency of these processes will have the same effect as variations in caloric intake. The human body requires glucose for the brain and nervous system, and a diet that has very few or no dietary carbohydrates forces it to generate this glucose from protein through gluconeogenesis, with an efficiency of approximately 57% (protein and carbohydrate are approximately
Metabolic advantage
73456
informal contexts, the term "carbohydrate" often means any food that is particularly rich in the complex carbohydrate starch (such as cereals, bread and pasta) or simple carbohydrates, such as sugar (found in candy, jams, and desserts). Often in lists of nutritional information, such as the USDA National Nutrient Database, the term "carbohydrate" (or "carbohydrate by difference") is used for everything other than water, protein, fat, ash, and ethanol. This includes chemical compounds such as acetic or lactic acid, which are not normally considered carbohydrates. It also includes dietary fiber which is a carbohydrate but which does not contribute much in
Carbohydrate
935264
details of metabolism, demonstrating that the oxidation of food is the source of body heat. In 1790 George Fordyce recognized calcium as necessary for fowl survival. In the early 19th century, the elements carbon, nitrogen, hydrogen and oxygen were recognized as the primary components of food, and methods to measure their proportions were developed. In 1816 François Magendie discovered that dogs fed only carbohydrates and fat lost their body protein and died in a few weeks, but dogs also fed protein survived, identifying protein as an essential dietary component. In 1840, Justus Liebig discovered the chemical makeup of carbohydrates (sugars),
Human nutrition
126404
energy flows in physical and biological systems by expressing energy units in human terms: it provides a "feel" for the use of a given amount of energy. Sunlight's radiant energy is also captured by plants as "chemical potential energy" in photosynthesis, when carbon dioxide and water (two low-energy compounds) are converted into the high-energy compounds carbohydrates, lipids, and proteins. Plants also release oxygen during photosynthesis, which is utilized by living organisms as an electron acceptor, to release the energy of carbohydrates, lipids, and proteins. Release of the energy stored during photosynthesis as heat or light may be triggered suddenly by
Energy
935177
Human nutrition Human nutrition deals with the provision of essential nutrients in food that are necessary to support human life and health. Poor nutrition is a chronic problem often linked to poverty, food security or a poor understanding of nutrition and dietary practices. Malnutrition and its consequences are large contributors to deaths and disabilities worldwide. Good nutrition helps children grow physically, promotes human biological development and helps in the eradication of poverty. The human body contains chemical compounds, such as water, carbohydrates, amino acids (in proteins), fatty acids (in lipids), and nucleic acids (DNA and RNA). These compounds are composed
Human nutrition
7467058
vivo biochemistry, which have had a major impact on human health worldwide. For landmark work on the mechanisms and regulation of ribonucleotide reductases, a compelling demonstration of the power of chemical investigations to solve problems in biology. For numerous innovative contributions at the interfaces of physical, organic, and inorganic chemistry, including the discoveries of alkane carbon-hydrogen bond oxidative addition and 1,4-benzene diradicals. For his wide-ranging accomplishments in natural products total synthesis and for his pioneering chemical synthesis of carbohydrates for the development of anticancer vaccines. For his leading role in the development of bioorganic chemistry, and especially for deep and
NAS Award in Chemical Sciences
11511080
surface of the enterocytes is the glycocalyx, which is a loose network composed of the oligosaccharide side chains of integral membrane hydrolases and other enzymes essential for the digestion of proteins and carbohydrates. These glycoproteins, glycolipids, and enzymes catalyze the final digestive stages of luminal carbohydrates and proteins. The monosaccharides and amino acids thus produced are subsequently transported across the intestinal epithelium and eventually into the bloodstream. The absorption of electrolytes and water is one of the most important functions of the digestive tract. Water absorption is passive and isotonic - depending on the speed and direction of solute flow.
Intestinal epithelium
757471
be produced in sufficient amounts by the cat. As it is an indispensable amino acid, it must be provided exogenously through the diet at 10 mg/kg bodyweight/day. Kittens deprived of taurine can experience poor growth and can result in retinal degeneration in cats. Felines are natural carnivores and do not intentionally consume large quantities of carbohydrates. The domestic cat's liver has adapted to the lack of carbohydrates in the diet by using amino acids to produce glucose to fuel the brain and other tissues. Studies have shown that carbohydrate digestion in young kittens is much less effective than that of
Kitten
4642452
bacterial hydrolysis of the input materials. Insoluble organic polymers, such as carbohydrates, are broken down to soluble derivatives that become available for other bacteria. Acidogenic bacteria then convert the sugars and amino acids into carbon dioxide, hydrogen, ammonia, and organic acids. These bacteria convert these resulting organic acids into acetic acid, along with additional ammonia, hydrogen, and carbon dioxide. Finally, methanogens convert these products to methane and carbon dioxide. The methanogenic archaea populations play an indispensable role in anaerobic wastewater treatments. Anaerobic digestion is used as part of the process to treat biodegradable waste and sewage sludge. As part of
Anaerobic digestion
14614243
produces gases (hydrogen, carbon dioxide and methane) and short-chain fatty acids (acetate, propionate, butyrate). The gases are absorbed and excreted by breathing or through the anus (flatulence). Fatty acids are rapidly metabolized. Butyrate is used mainly by cells in the colon and acetate is absorbed into the blood and taken up by the liver, muscle and other tissue. Propionate is an important precursor of glucose in some animals, but not humans. Carbohydrate digestion All carbohydrates absorbed in the small intestine must be hydrolyzed to monosaccharides prior to absorption. Hydrolysis precedes transport of monosaccharides in hamster intestine. From sucrose, glucose is
Carbohydrate digestion
16702294
or common matter (chemistry) cannot be employed to any useful end in understanding living matter (physiology). As an example, the "assimilating and convertible power" or "converting power of the assimilating organ" found in digestion, as "proved by Mr. Hunter and Spallanzani" cannot be explained by chemical laws and actions, but must be performed by a "living power resident in the organ and its secretions, in this case, that of the gastric juice of animals and man." From all of his observations of the facts from previous experiments, Saumarez is led to the logical conclusion that "the process of digestion...is not
Richard Saumarez
8150200
monosaccharides in the small intestine. Acarbose also blocks pancreatic alpha-amylase in addition to inhibiting membrane-bound alpha-glucosidases. Pancreatic alpha-amylase hydrolyzes complex starches to oligosaccharides in the lumen of the small intestine. Inhibition of these enzyme systems reduces the rate of digestion of carbohydrates. Less glucose is absorbed because the carbohydrates are not broken down into glucose molecules. In diabetic patients, the short-term effect of these drugs therapies is to decrease current blood glucose levels: the long-term effect is a small reduction in hemoglobin level. Since alpha-glucosidase inhibitors are competitive inhibitors of digestive enzymes, they must be taken at the start of
Alpha-glucosidase inhibitor
4179508
as 38 percent. Breath tests have their own reliability problems with a high rate of false positive. Some doctors factor in a patients' response to treatment as part of the diagnosis. Breath tests have been developed to test for bacterial overgrowth, based on bacterial metabolism of carbohydrates to hydrogen and/or methane, or based on the detection of by-products of digestion of carbohydrates that are not usually metabolized. The hydrogen breath test involves having the patient fast for a minimum of 12 hours then having them drink a substrate usually glucose or lactulose, then measuring expired hydrogen and methane concentrations typically
Small intestinal bacterial overgrowth
16143760
there wasn't a producer of IMO in North America and Europe until recently when BioNeutra North America, Inc. began to manufacture this product with the VitaFiber IMO trademark. US-based companies have been in producing other kinds of oligosaccharides, like GOS, FOS, and XOS. Isomaltooligosaccharide Isomaltooligosaccharide (IMO) is a mixture of short-chain carbohydrates which has a digestion-resistant property. IMO is found naturally in some foods, as well as being manufactured commercially. The raw material used for manufacturing IMO is starch, which is enzymatically converted into a mixture of isomaltooligosaccharides. The term "oligosaccharide" encompasses carbohydrates that are larger than simple di- or
Isomaltooligosaccharide
2897672
an intake of oxygen along with coenzymes to provide energy for survival (usually from macronutrients like carbohydrates, fats, and proteins) and expel carbon dioxide, due to processing by the Krebs cycle. For the BMR, most of the energy is consumed in maintaining fluid levels in tissues through osmoregulation, and only about one-tenth is consumed for mechanical work, such as digestion, heartbeat, and breathing. What enables the Krebs cycle to perform metabolic changes to fats, carbohydrates, and proteins is energy, which can be defined as the ability or capacity to do work. The breakdown of large molecules into smaller molecules—associated with
Basal metabolic rate
172058
pancreas. When congenital hyperinsulinism is diffuse and refractory to medications, near-total pancreatectomy may be the treatment of last resort, but in this condition is less consistently effective and fraught with more complications. Hypoglycemia due to hormone deficiencies such as hypopituitarism or adrenal insufficiency usually ceases when the appropriate hormone is replaced. Hypoglycemia due to dumping syndrome and other post-surgical conditions is best dealt with by altering diet. Including fat and protein with carbohydrates may slow digestion and reduce early insulin secretion. Some forms of this respond to treatment with an alpha-glucosidase inhibitor, which slows starch digestion. Reactive hypoglycemia with demonstrably
Hypoglycemia
648170
disorders exist in which an individual's metabolism of biotin is abnormal, such as deficiency in the holocarboxylase synthetase enzyme which covalently links biotin onto the carboxylase, where the biotin acts as a cofactor. Biotin is composed of a ureido ring fused with a tetrahydrothiophene ring. The ureido ring acts as the carbon dioxide carrier in carboxylation reactions. A valeric acid substituent is attached to one of the carbon atoms of the tetrahydrothiophene ring. Biotin is a coenzyme for multiple carboxylase enzymes, which are involved in the digestion of carbohydrates, synthesis of fatty acids, and gluconeogenesis. Biotin is also required for
Biotin
6065877
"Sylvius Laboratory". His most famous students were Jan Swammerdam, Reinier de Graaf, Niels Stensen and Burchard de Volder. He founded the Iatrochemical School of Medicine, according to which all life and disease processes are based on chemical actions. That school of thought attempted to understand medicine in terms of universal rules of physics and chemistry. Sylvius also introduced the concept of chemical affinity as a way to understand the way the human body uses salts and contributed greatly to the understanding of digestion and of bodily fluids. The most important work he published was "Praxeos medicae idea nova" ("New Idea
Franciscus Sylvius
17916229
Human digestive system The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder). Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has many stages. The first stage is the cephalic phase of digestion which begins with gastric secretions in response to the sight and smell of food. The next stage starts in the mouth. Chewing, in which food is mixed with saliva, begins the mechanical process of digestion. This produces
Human digestive system
1691176
of which represent important stereochemical information about the forms they depict. Aldose An aldose is a monosaccharide (a simple sugar) with a carbon backbone chain with a carbonyl group on the endmost carbon atom, making it an aldehyde, and hydroxyl groups connected to all the other carbon atoms. Aldoses can be distinguished from ketoses, which have the carbonyl group away from the end of the molecule, and are therefore ketones. Like most carbohydrates, simple aldoses have the general chemical formula C(HO). Because formaldehyde (n=1) and glycolaldehyde (n=2) are not generally considered to be carbohydrates, the simplest possible aldose is the
Aldose
15039417
the decomposition products should reflect the amount of protein and fat content initially present in the body. As such, the chemical process of decomposition involves the breakdown of proteins, carbohydrates, lipids, nucleic acids, and bone. Proteins make up a variety of different tissues within the body, which may be classified as soft or hard tissue proteins. As such, proteins within the body are not degraded at a uniform rate. Proteolysis is the process that breaks down proteins. It is regulated by moisture, temperature, and bacteria. This process does not occur at a uniform rate and thus some proteins are degraded
Chemical process of decomposition
240365
many natural polymers vary in composition (for instance DNA, proteins, carbohydrates) even when "pure". Polymers are generally not considered "pure chemical compounds" except when their molecular weight is uniform (monodisperse) and their stoichiometry is constant. In this unusual case, they still may violate the law due to isotopic variations. Law of definite proportions In chemistry, the law of definite proportion, sometimes called Proust's law or the law of definite composition, or law of constant composition states that a given chemical compound always contains its component elements in fixed ratio (by mass) and does not depend on its source and method
Law of definite proportions
1691171
Aldose An aldose is a monosaccharide (a simple sugar) with a carbon backbone chain with a carbonyl group on the endmost carbon atom, making it an aldehyde, and hydroxyl groups connected to all the other carbon atoms. Aldoses can be distinguished from ketoses, which have the carbonyl group away from the end of the molecule, and are therefore ketones. Like most carbohydrates, simple aldoses have the general chemical formula C(HO). Because formaldehyde (n=1) and glycolaldehyde (n=2) are not generally considered to be carbohydrates, the simplest possible aldose is the triose glyceraldehyde, which only contains three carbon atoms. Because they have
Aldose
126405
a spark, in a forest fire, or it may be made available more slowly for animal or human metabolism, when these molecules are ingested, and catabolism is triggered by enzyme action. Any living organism relies on an external source of energy – radiant energy from the Sun in the case of green plants, chemical energy in some form in the case of animals – to be able to grow and reproduce. The daily 1500–2000 Calories (6–8 MJ) recommended for a human adult are taken as a combination of oxygen and food molecules, the latter mostly carbohydrates and fats, of which
Energy
8385442
on soil-born diseases, and an indirect effect by stimulation of biological activity. Digestate is technically not compost although it is similar to it in physical and chemical characteristics. Compost is produced by aerobic digestion- decomposition by aerobes. This includes fungi and bacteria which are able to break down the lignin and cellulose to a greater extent. The standard of digestate produced by anaerobic digestion can be assessed on three criteria, chemical, biological and physical aspects. Chemical quality needs to be considered in terms of heavy metals and other inorganic contaminant, persistent organic compounds and the content of macro-elements such as
Digestate
4642456
from materials with existing populations, a process known as "seeding" the digesters, typically accomplished with the addition of sewage sludge or cattle slurry. The four key stages of anaerobic digestion involve hydrolysis, acidogenesis, acetogenesis and methanogenesis. The overall process can be described by the chemical reaction, where organic material such as glucose is biochemically digested into carbon dioxide (CO) and methane (CH) by the anaerobic microorganisms. In most cases, biomass is made up of large organic polymers. For the bacteria in anaerobic digesters to access the energy potential of the material, these chains must first be broken down into their
Anaerobic digestion
17916294
predispose for certain digestive disorders. Gestational diabetes can develop in the mother as a result of pregnancy and while this often presents with few symptoms it can lead to pre-eclampsia. Human digestive system The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder). Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has many stages. The first stage is the cephalic phase of digestion which begins with gastric secretions in response
Human digestive system
11903481
Inborn errors of carbohydrate metabolism Inborn errors of carbohydrate metabolism are inborn error of metabolism that affect the catabolism and anabolism of carbohydrates. An example is lactose intolerance. Carbohydrates account for a major portion of the human diet. These carbohydrates are composed of three principal monosaccharides: glucose, fructose and galactose; in addition glycogen is the storage form of carbohydrates in humans. The failure to effectively use these molecules accounts for the majority of the inborn errors of human carbohydrates metabolism. Glycogen storage diseases are enzyme deficiencies which impair glycogen synthesis, glycogen degradation or glycolysis. The two organs most commonly affected
Inborn errors of carbohydrate metabolism
11399396
is a lipid constituent of cell membrane, and a dietary component being particularly abundant in milk, cheese, egg, and meat. Digestion of sphingomyelin mainly occurs in the middle part of the small intestine, where ENPP7 is abundant, indicating a role of the enzyme in sphingomyelin digestion. Recent studies on ENPP7 knockout mice clearly showed that digestion of sphingomyelin and generation of ceramide is severely affected in ENPP7 deficiency mice. ENPP7 is fully developed in the intestine before birth, which gives the infant ability to digest sphingomyelin in the milk. The daily intake of sphingomyelin for human with Western diet is
ENPP7
12785268
important to the environment, but it can be cost effective by decreasing the amount of waste sent to the disposal stream, reduce the amount of space needed for landfills, and protect limited natural resources. Energy recovery from waste is using non-recyclable waste materials and extracting from it heat, electricity, or energy through a variety of processes, including combustion, gasification, pyrolyzation, and anaerobic digestion. This process is referred to as waste-to-energy. There are several ways to recover energy from waste. Anaerobic digestion is a naturally occurring process of decomposition where organic matter is reduced to a simpler chemical component in the
Waste
20250983
Healthy digestion Healthy digestion, also called digestive health, results in the absorption of nutrients from food without distressing symptoms. Healthy digestion follows having a healthy diet, doing appropriate self-care including physical activity and exercise, minimizing activities like smoking or consuming alcoholic drinks which impair digestion, and managing any medical condition which disrupts digestion to the best of one's ability. A person with healthy digestion will have lower risk of experiencing diarrhea, constipation, heartburn, bloating, flatulence, and indigestion. Additionally, a person with healthy digestion will have less need of digestive medications than a person who does not have healthy digestion. Some
Healthy digestion
10891942
(SDS-PAGE). This dimension separates the protein according to its molecular weight. Once this step is completed in-gel digestion occurs. In some situations, it may be necessary to combine both of these techniques. Gel spots identified on a 2D Gel are usually attributable to one protein. If the identity of the protein is desired, usually the method of in-gel digestion is applied, where the protein spot of interest is excised, and digested proteolytically. The peptide masses resulting from the digestion can be determined by mass spectrometry using peptide mass fingerprinting. If this information does not allow unequivocal identification of the protein,
Protein mass spectrometry
2135262
diastase in 1833. By the end of the 19th century the concept of enzymes was well established, though equations of chemical kinetics would not be applied to enzymatic reactions until the early 20th century. Physiologists such as Claude Bernard explored (through vivisection and other experimental methods) the chemical and physical functions of living bodies to an unprecedented degree, laying the groundwork for endocrinology (a field that developed quickly after the discovery of the first hormone, secretin, in 1902), biomechanics, and the study of nutrition and digestion. The importance and diversity of experimental physiology methods, within both medicine and biology, grew
History of biology
4642485
to predict biogas composition (the relative fractions of methane and carbon dioxide) it is necessary to estimate carbon dioxide partitioning between the aqueous and gas phases, which requires additional information (reactor temperature, pH, and substrate composition) and a chemical speciation model. Using anaerobic digestion technologies can help to reduce the emission of greenhouse gases in a number of key ways: Anaerobic digestion is particularly suited to organic material, and is commonly used for industrial effluent, wastewater and sewage sludge treatment. Anaerobic digestion, a simple process, can greatly reduce the amount of organic matter which might otherwise be destined to be
Anaerobic digestion
935192
subcategories are insoluble and soluble fiber. Insoluble dietary fiber consists mainly of cellulose, a large carbohydrate polymer that is indigestible by humans, because humans do not have the required enzymes to break it down, and the human digestive system does not harbor enough of the types of microbes that can do so. Soluble dietary fiber comprises a variety of oligosaccharides, waxes, esters, resistant starches, and other carbohydrates that dissolve or gelatinize in water. Many of these soluble fibers can be fermented or partially fermented by microbes in the human digestive system to produce short-chain fatty acids which are absorbed and
Human nutrition
1294743
debate over its significance in human nutrition. Boron's chemistry does allow it to form complexes with such important molecules as carbohydrates, so it is plausible that it could be of greater use in the human body than previously thought. Boron has also been shown to be able to replace iron in some of its functions, particularly in the healing of wounds. Aluminium has no known biological role in plants or animals. Gallium is not essential for the human body, but its relation to iron(III) allows it to become bound to proteins that transport and store iron. Gallium can also stimulate
Boron group
1535994
Food energy Food energy is chemical energy that animals (including humans) derive from food through the process of cellular respiration. Cellular respiration may either involve the chemical reaction of food molecules with molecular oxygen (aerobic respiration) or the process of reorganizing the food molecules without additional oxygen (anaerobic respiration). Humans and other animals need a minimum intake of food energy to sustain their metabolism and to drive their muscles. Foods are composed chiefly of carbohydrates, fats, proteins, water, vitamins, and minerals. Carbohydrates, fats, proteins, and water represent virtually all the weight of food, with vitamins and minerals making up only
Food energy
15405456
the chemical energy contained within the starting material is released by methanogenic bacteria as methane. Populations of anaerobic microorganisms typically take a significant period of time to establish themselves to be fully effective. It is therefore common practice to introduce anaerobic microorganisms from materials with existing populations, a process known as "seeding" the digesters, and typically takes place with the addition of sewage sludge or cattle slurry. The key process stages of anaerobic digestion There are four key biological and chemical stages of anaerobic digestion: 1. Hydrolysis 2. Acidogenesis 3. Acetogenesis 4. Methanogenesis In most cases biomass is made up
Jundiz recycling plant
376072
ratio is credited to Archimedes. Surface area is important in chemical kinetics. Increasing the surface area of a substance generally increases the rate of a chemical reaction. For example, iron in a fine powder will combust, while in solid blocks it is stable enough to use in structures. For different applications a minimal or maximal surface area may be desired. The surface area of an organism is important in several considerations, such as regulation of body temperature and digestion. Animals use their teeth to grind food down into smaller particles, increasing the surface area available for digestion. The epithelial tissue
Surface area
13261424
and lactose, were trivially named before their chemical constitution was determined, and these names are still used today. Trivial names, however, are not useful for most other oligosaccharides and, as such, systematic rules for the nomenclature of carbohydrates have been developed. To fully understand oligosaccharide and polysaccharide nomenclature, one must understand how monosaccharides are named. An oligosaccharide has both a reducing and a non-reducing end. The reducing end of an oligosaccharide is the monosaccharide residue with hemiacetal functionality, thereby capable of reducing the Tollens’ reagent, while the non-reducing end is the monosaccharide residue in acetal form, thus incapable of reducing
Oligosaccharide nomenclature
11139865
input material. When the oxygen source in an anaerobic system is derived from the organic material itself, then the 'intermediate' end products are primarily alcohols, aldehydes, and organic acids plus carbon dioxide. In the presence of specialised methanogens, the intermediates are converted to the 'final' end products of methane, carbon dioxide with trace levels of hydrogen sulfide. In an anaerobic system the majority of the chemical energy contained within the starting material is released by methanogenic bacteria as methane. In an aerobic system, such as composting, the microorganisms access free, gaseous oxygen directly from the surrounding atmosphere. The end products
Comparison of anaerobic and aerobic digestion
12459973
the mRNA. In a second group of methods, initiation of second-strand synthesis takes place outside the sequence of the first strand. This group of methods does not require digestion of the 3' end of the first strand. However, the limitation of this group of method lies upon the elongation. Cloning with T7 DNA polymerase helps overcome this limitation by allowing digestion of the poly(dT) tract during the second-strand synthesis reaction. Therefore, the size of the tract synthesized with terminal transferase is not required to be within a given size range and the resulting clones contain a tract of a limited
T7 DNA polymerase
2796613
Furanose A furanose is a collective term for carbohydrates that have a chemical structure that includes a five-membered ring system consisting of four carbon atoms and one oxygen atom. The name derives from its similarity to the oxygen heterocycle furan, but the furanose ring does not have double bonds. The furanose ring is a cyclic hemiacetal of an aldopentose or a cyclic hemiketal of a ketohexose. A furanose ring structure consists of four carbon and one oxygen atom with the anomeric carbon to the right of the oxygen. The highest numbered chiral carbon (typically to the left of the oxygen
Furanose
2796615
solution, and the result is an equilibrium mixture of alpha-beta configurations. Furanose A furanose is a collective term for carbohydrates that have a chemical structure that includes a five-membered ring system consisting of four carbon atoms and one oxygen atom. The name derives from its similarity to the oxygen heterocycle furan, but the furanose ring does not have double bonds. The furanose ring is a cyclic hemiacetal of an aldopentose or a cyclic hemiketal of a ketohexose. A furanose ring structure consists of four carbon and one oxygen atom with the anomeric carbon to the right of the oxygen. The
Furanose
10062269
can also be burned directly in modified engines to greatly reduce greenhouse gas emissions. Cellulosic ethanol is an environmentally friendly and renewable transportation fuel that can be produced from forest biomass. Trees are a particularly promising feedstock because they grow all year round, require vastly less fertiliser and water and contain far more carbohydrates (the chemical precursors of ethanol) than food crops do. Also, compared to corn ethanol, cellulosic biofuel does not require the same quantity of fertilizers, pesticides, energy, or water to grow. The most important attribute of this type of ethanol is, like all types of ethanol, it
Treethanol
1536002
values given on food labels are not determined in this way. The reason for this is that direct calorimetry also burns the dietary fiber, and so does not allow for fecal losses; thus direct calorimetry would give systematic overestimates of the amount of fuel that actually enters the blood through digestion. What are used instead are standardized chemical tests or an analysis of the recipe using reference tables for common ingredients to estimate the product's digestible constituents (protein, carbohydrate, fat, etc.). These results are then converted into an equivalent energy value based on the following standardized table of energy densities.
Food energy
11017943
join the others to investigate the diet in the prison system. He inspired two German researchers to investigate the prevailing idea that protein alone powered muscles. Adolf Eugen Fick and Johannes Wislicenus climbed the Swiss Alps after removing protein entirely from their diet. They were then able to balance the food they had consumed against the gain in potential energy. They were able to show as Smith had suggested that the chemical energy required for muscular effort does not come primarily from consumed protein but from fats and carbohydrates. Edward Smith died of pneumonia in 1874. His wife, Matilda Frearson,
Edward Smith (physician)
1828964
extend their corrosive effects on living tissue. For example, sulfuric acid (HSO) at a high concentration is also a strong dehydrating agent, capable of dehydrating carbohydrates and liberating extra heat. This results in secondary thermal burns in addition to the chemical burns and may speed up its decomposing reactions on the contact surface. Some corrosives, such as nitric acid and concentrated sulfuric acid, are strong oxidizing agents as well, which significantly contributes to the extra damage caused. Hydrofluoric acid does not necessarily cause noticeable damage upon contact, but produces tissue damage and toxicity after being painlessly absorbed. Zinc chloride solutions
Corrosive substance