Glucose

Source: Wikipedia, the free encyclopedia.
(Redirected from
Dextrose
)
d-Glucose

Skeletal formula of d-glucose

Haworth projection of α-d-glucopyranose

Fischer projection of d-glucose
Names
Pronunciation /ˈɡlkz/, /ɡlks/
IUPAC name
Allowed trivial names:[1]
  • ᴅ-Glucose
  • ᴅ-gluco-Hexose
Preferred IUPAC name
PINs are not identified for natural products.
Systematic IUPAC name
  • (2R,3S,4R,5R)-2,3,4,5,6-Pentahydroxyhexanal (linear form)
  • (3R,4S,5S,6R)-6-(hydroxymethyl)oxane-2,3,4,5-tetrol (cyclic form)
Other names
Blood sugars
Dextrose
Corn sugar
d-Glucose
Grape sugar
Identifiers
3D model (
JSmol
)
3DMet
Abbreviations Glc
1281604
ChEBI
ChEMBL
ChemSpider
EC Number
  • 200-075-1
83256
IUPHAR/BPS
KEGG
MeSH Glucose
RTECS number
  • LZ6600000
UNII
  • InChI=1S/C6H12O6/c7-1-2-3(8)4(9)5(10)6(11)12-2/h2-11H,1H2/t2-,3-,4+,5-,6?/m1/s1 checkY
    Key: WQZGKKKJIJFFOK-GASJEMHNSA-N checkY
  • OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O
  • C([C@@H]1[C@H]([C@@H]([C@H]([C@H](O1)O)O)O)O)O
Properties
C6H12O6
Molar mass 180.156 g/mol
Appearance White powder
Density 1.54 g/cm3
Melting point α-d-Glucose: 146 °C (295 °F; 419 K) β-d-Glucose: 150 °C (302 °F; 423 K)
909 g/L (25 °C (77 °F))
−101.5×10−6 cm3/mol
8.6827
Thermochemistry
218.6 J/(K·mol)[2]
209.2 J/(K·mol)[2]
Std enthalpy of
formation
fH298)
−1271 kJ/mol[3]
2,805 kJ/mol (670 kcal/mol)
Pharmacology
B05CX01 (WHO) V04CA02 (WHO), V06DC01 (WHO)
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 0: Exposure under fire conditions would offer no hazard beyond that of ordinary combustible material. E.g. sodium chlorideFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
0
1
0
Safety data sheet (SDS) ICSC 08655
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Glucose is a

plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight, where it is used to make cellulose in cell walls, the most abundant carbohydrate in the world.[5][6][7]

In

aldohexose. The glucose molecule can exist in an open-chain (acyclic) as well as ring (cyclic) form. Glucose is naturally occurring and is found in its free state in fruits and other parts of plants. In animals, glucose is released from the breakdown of glycogen in a process known as glycogenolysis
.

Glucose, as intravenous sugar solution, is on the World Health Organization's List of Essential Medicines.[8] It is also on the list in combination with sodium chloride (table salt).[8]

The name glucose is derived from Ancient Greek γλεῦκος (gleûkos, "wine, must"), from γλυκύς (glykýs, "sweet").[9][10] The suffix "-ose" is a chemical classifier denoting a sugar.

History

Glucose was first isolated from

Friedrich August Kekulé proposed the term dextrose (from the Latin dexter, meaning "right"), because in aqueous solution of glucose, the plane of linearly polarized light is turned to the right. In contrast, l-fructose (usually referred to as d-fructose) (a ketohexose) and l-glucose (l-glucose) turn linearly polarized light to the left. The earlier notation according to the rotation of the plane of linearly polarized light (d and l-nomenclature) was later abandoned in favor of the d- and l-notation, which refers to the absolute configuration of the asymmetric center farthest from the carbonyl group, and in concordance with the configuration of d- or l-glyceraldehyde.[13][14]

Since glucose is a basic necessity of many organisms, a correct understanding of its

Emil Fischer, a German chemist who received the 1902 Nobel Prize in Chemistry for his findings.[15] The synthesis of glucose established the structure of organic material and consequently formed the first definitive validation of Jacobus Henricus van 't Hoff's theories of chemical kinetics and the arrangements of chemical bonds in carbon-bearing molecules.[16] Between 1891 and 1894, Fischer established the stereochemical configuration of all the known sugars and correctly predicted the possible isomers
, applying Van 't Hoff's theory of asymmetrical carbon atoms. The names initially referred to the natural substances. Their enantiomers were given the same name with the introduction of systematic nomenclatures, taking into account absolute stereochemistry (e.g. Fischer nomenclature, d/l nomenclature).

For the discovery of the metabolism of glucose

Luis Leloir was awarded the Nobel Prize in Chemistry for the discovery of glucose-derived sugar nucleotides in the biosynthesis of carbohydrates.[23]

Chemical and physical properties

Glucose forms white or colorless solids that are highly soluble in water and acetic acid but poorly soluble in methanol and ethanol. They melt at 146 °C (295 °F) (α) and 150 °C (302 °F) (beta), decompose starting at 188 °C (370 °F) with release of various volatile products, ultimately leaving a residue of carbon.[24] Glucose has a pKa value of 12.16 at 25 °C (77 °F) in water.[25]

With six carbon atoms, it is classed as a

tapioca starch in tropical areas.[26] The manufacturing process uses hydrolysis via pressurized steaming at controlled pH in a jet followed by further enzymatic depolymerization.[27] Unbonded glucose is one of the main ingredients of honey.[28][29][30][31][32]

The term "dextrose" is often used in a clinical (related to patient's health status) or nutritional context (related to dietary intake, such as food labels or dietary guidelines), while "glucose" is used in a biological or physiological context (chemical processes and molecular interactions),[33][34][35][36] but both terms refer to the same molecule, specifically D-glucose.[35][37]

Dextrose monohydrate is the hydrated form of D-glucose, meaning that it is a glucose molecule with an additional water molecule attached.[38] Its chemical formula is C6H12O6 · H2O.[38][39] Dextrose monohydrate is also called hydrated D-glucose, and commonly manufactured from plant starches such as corn starch or potato starch.[38][40] Dextrose monohydrate is utilized as the predominant type of dextrose in food applications, such as beverage mixes—it is a common form of glucose widely used as a nutrition supplement in production of foodstuffs. Dextrose monohydrate is primarily consumed in North America as a corn syrup or high-fructose corn syrup.[35]

Anhydrous dextrose, on the other hand, is glucose that does not have any water molecules attached to it.[40] [41] Anhydrous chemical substances are commonly produced by eliminating water from a hydrated substance through methods such as heating or drying up (desiccation).[42][43][44]Dextrose monohydrate can be dehydrated to anhydrous dextrose in industrial setting.[45][46] Dextrose monohydrate is composed of approximately 9.5% water by mass. Through the process of dehydration, this water content is eliminated to yield anhydrous (dry) dextrose.[40]

Anhydrous dextrose has the chemical formula C6H12O6, without any water molecule attached which is the same as glucose.[38] Anhydrous dextrose on open air tends to absorb moisture and transform to the monohydrate, and it is more expensive to produce.[40] Anhydrous dextrose (anhydrous D-glucose) has increased stability and increased shelf life,[43] has medical applications, such as in oral glucose tolerance test (OGTT).[47]

Whereas molecular weight (molar mass) for D-glucose monohydrate is 198.17 g/mol,[48][49] that for anhydrous D-glucose is 180.16 g/mol[50][51][52] The density of these two forms of glucose is also different.[specify]

In terms of chemical structure, glucose is a monosaccharide containing six carbon atoms and an aldehyde group, and is therefore an aldohexose. The glucose molecule can exist in an open-chain (acyclic) as well as ring (cyclic) form—due to the presence of alcohol and aldehyde or ketone functional groups, the form having the straight chain can easily convert into a chair-like hemiacetal ring structure commonly found in carbohydrates.[53]

Structure and nomenclature

Mutarotation of glucose

Glucose is usually present in solid form as a

glass transition temperature of glucose is 31 °C (88 °F) and the Gordon–Taylor constant (an experimentally determined constant for the prediction of the glass transition temperature for different mass fractions of a mixture of two substances)[55] is 4.5.[56]

Forms and projections of d-glucose in comparison
Natta projection Haworth projection
α-d-glucofuranose
β-d-glucofuranose
α-d-glucopyranose
β-d-glucopyranose
α-d-Glucopyranose in (1) Tollens/Fischer (2) Haworth projection (3) chair conformation (4) Mills projection

Open-chain form

Glucose can exist in both a straight-chain and ring form.

A open-chain form of glucose makes up less than 0.02% of the glucose molecules in an aqueous solution at equilibrium.

Fehling test
.

Cyclic forms

Cyclic forms of glucose
From left to right: Haworth projections and ball-and-stick structures of the α- and β- anomers of D-glucopyranose (top row) and D-glucofuranose (bottom row)

In solutions, the open-chain form of glucose (either "D-" or "L-") exists in equilibrium with several cyclic isomers, each containing a ring of carbons closed by one oxygen atom. In aqueous solution, however, more than 99% of glucose molecules exist as pyranose forms. The open-chain form is limited to about 0.25%, and furanose forms exist in negligible amounts. The terms "glucose" and "D-glucose" are generally used for these cyclic forms as well. The ring arises from the open-chain form by an intramolecular nucleophilic addition reaction between the aldehyde group (at C-1) and either the C-4 or C-5 hydroxyl group, forming a hemiacetal linkage, −C(OH)H−O−.

The reaction between C-1 and C-5 yields a six-membered

heterocyclic system called a pyranose, which is a monosaccharide sugar (hence "-ose") containing a derivatised pyran skeleton. The (much rarer) reaction between C-1 and C-4 yields a five-membered furanose ring, named after the cyclic ether furan
. In either case, each carbon in the ring has one hydrogen and one hydroxyl attached, except for the last carbon (C-4 or C-5) where the hydroxyl is replaced by the remainder of the open molecule (which is −(C(CH2OH)HOH)−H or −(CHOH)−H respectively).

The ring-closing reaction can give two products, denoted "α-" and "β-". When a glucopyranose molecule is drawn in the Haworth projection, the designation "α-" means that the hydroxyl group attached to C-1 and the −CH2OH group at C-5 lies on opposite sides of the ring's plane (a trans arrangement), while "β-" means that they are on the same side of the plane (a cis arrangement). Therefore, the open-chain isomer D-glucose gives rise to four distinct cyclic isomers: α-D-glucopyranose, β-D-glucopyranose, α-D-glucofuranose, and β-D-glucofuranose. These five structures exist in equilibrium and interconvert, and the interconversion is much more rapid with acid catalysis.

Widely proposed arrow-pushing mechanism for acid-catalyzed dynamic equilibrium between the α- and β- anomers of D-glucopyranose
Widely proposed arrow-pushing mechanism for acid-catalyzed dynamic equilibrium between the α- and β- anomers of D-glucopyranose
Chair conformations
of α- (left) and β- (right) D-glucopyranose

The other open-chain isomer L-glucose similarly gives rise to four distinct cyclic forms of L-glucose, each the mirror image of the corresponding D-glucose.

The glucopyranose ring (α or β) can assume several non-planar shapes, analogous to the "chair" and "boat" conformations of cyclohexane. Similarly, the glucofuranose ring may assume several shapes, analogous to the "envelope" conformations of cyclopentane.

In the solid state, only the glucopyranose forms are observed.

Some derivatives of glucofuranose, such as 1,2-O-isopropylidene-D-glucofuranose are stable and can be obtained pure as crystalline solids.[58][59] For example, reaction of α-D-glucose with para-tolylboronic acid H3C−(C6H4)−B(OH)2 reforms the normal pyranose ring to yield the 4-fold ester α-D-glucofuranose-1,2:3,5-bis(p-tolylboronate).[60]

Mutarotation

Mutarotation: d-glucose molecules exist as cyclic hemiacetals that are epimeric (= diastereomeric) to each other. The epimeric ratio α:β is 36:64. In the α-D-glucopyranose (left), the blue-labelled hydroxy group is in the axial position at the anomeric centre, whereas in the β-D-glucopyranose (right) the blue-labelled hydroxy group is in equatorial position at the anomeric centre.

Mutarotation consists of a temporary reversal of the ring-forming reaction, resulting in the open-chain form, followed by a reforming of the ring. The ring closure step may use a different −OH group than the one recreated by the opening step (thus switching between pyranose and furanose forms), or the new hemiacetal group created on C-1 may have the same or opposite handedness as the original one (thus switching between the α and β forms). Thus, though the open-chain form is barely detectable in solution, it is an essential component of the equilibrium.

The open-chain form is thermodynamically unstable, and it spontaneously isomerizes to the cyclic forms. (Although the ring closure reaction could in theory create four- or three-atom rings, these would be highly strained, and are not observed in practice.) In solutions at room temperature, the four cyclic isomers interconvert over a time scale of hours, in a process called mutarotation.[61] Starting from any proportions, the mixture converges to a stable ratio of α:β 36:64. The ratio would be α:β 11:89 if it were not for the influence of the anomeric effect.[62] Mutarotation is considerably slower at temperatures close to 0 °C (32 °F).

Optical activity

Whether in water or the solid form, d-(+)-glucose is

levorotatory (rotates polarized light counterclockwise) by the same amount. The strength of the effect is different for each of the five tautomers
.

Note that the d- prefix does not refer directly to the optical properties of the compound. It indicates that the C-5 chiral centre has the same handedness as that of d-glyceraldehyde (which was so labelled because it is dextrorotatory). The fact that d-glucose is dextrorotatory is a combined effect of its four chiral centres, not just of C-5; and indeed some of the other d-aldohexoses are levorotatory.

The conversion between the two anomers can be observed in a polarimeter since pure α-d-glucose has a specific rotation angle of +112.2° mL/(dm·g), pure β-d-glucose of +17.5° mL/(dm·g).[63] When equilibrium has been reached after a certain time due to mutarotation, the angle of rotation is +52.7° mL/(dm·g).[63] By adding acid or base, this transformation is much accelerated. The equilibration takes place via the open-chain aldehyde form.

Isomerisation

In dilute

enediol
:

Glucose-Fructose-Mannose-isomerisation

Biochemical properties

Glucose is the most abundant monosaccharide. Glucose is also the most widely used aldohexose in most living organisms. One possible explanation for this is that glucose has a lower tendency than other aldohexoses to react nonspecifically with the

esterification[67]: 363  or acetal formation.[68] For this reason, d-glucose is also a highly preferred building block in natural polysaccharides (glycans). Polysaccharides that are composed solely of glucose are termed glucans
.

Glucose is produced by plants through photosynthesis using sunlight,

erythrocytes depend on glucose for their energy production.[70] In adult humans, there is about 18 g (0.63 oz) of glucose,[71] of which about 4 g (0.14 oz) is present in the blood.[72] Approximately 180–220 g (6.3–7.8 oz) of glucose is produced in the liver of an adult in 24 hours.[71]

Many of the long-term complications of diabetes (e.g., blindness, kidney failure, and peripheral neuropathy) are probably due to the glycation of proteins or lipids.[73] In contrast, enzyme-regulated addition of sugars to protein is called glycosylation and is essential for the function of many proteins.[74]

Uptake

Ingested glucose initially binds to the receptor for sweet taste on the tongue in humans. This complex of the proteins

mucopolysaccharides, and poly(ADP-ribose). Humans do not produce cellulases, chitinases, or trehalases, but the bacteria in the gut microbiota
do.

In order to get into or out of cell membranes of cells and membranes of cell compartments, glucose requires special transport proteins from the

basolateral side of the intestinal epithelial cells via the glucose transporter GLUT2,[79] as well uptake into liver cells, kidney cells, cells of the islets of Langerhans, neurons, astrocytes, and tanycytes.[80] Glucose enters the liver via the portal vein and is stored there as a cellular glycogen.[81] In the liver cell, it is phosphorylated by glucokinase at position 6 to form glucose 6-phosphate, which cannot leave the cell. Glucose 6-phosphatase can convert glucose 6-phosphate back into glucose exclusively in the liver, so the body can maintain a sufficient blood glucose concentration. In other cells, uptake happens by passive transport through one of the 14 GLUT proteins.[79] In the other cell types, phosphorylation occurs through a hexokinase
, whereupon glucose can no longer diffuse out of the cell.

The glucose transporter

SGLT2 in the apical cell membranes and transmitted via GLUT2 in the basolateral cell membranes.[85] About 90% of kidney glucose reabsorption is via SGLT2 and about 3% via SGLT1.[86]

Biosynthesis

In plants and some prokaryotes, glucose is a product of photosynthesis.[69] Glucose is also formed by the breakdown of polymeric forms of glucose like glycogen (in animals and mushrooms) or starch (in plants). The cleavage of glycogen is termed glycogenolysis, the cleavage of starch is called starch degradation.[87]

The metabolic pathway that begins with molecules containing two to four carbon atoms (C) and ends in the glucose molecule containing six carbon atoms is called gluconeogenesis and occurs in all living organisms. The smaller starting materials are the result of other metabolic pathways. Ultimately almost all

tubular cells
can also produce glucose.

Glucose also can be found outside of living organisms in the ambient environment. Glucose concentrations in the atmosphere are detected via collection of samples by aircraft and are known to vary from location to location. For example, glucose concentrations in atmospheric air from inland China range from 0.8 to 20.1 pg/L, whereas east coastal China glucose concentrations range from 10.3 to 142 pg/L.[90]

Glucose degradation

Glucose metabolism and various forms of it in the process.
Glucose-containing compounds and isomeric forms are digested and taken up by the body in the intestines, including starch, glycogen, disaccharides and monosaccharides.
Glucose is stored in mainly the liver and muscles as glycogen. It is distributed and used in tissues as free glucose.

In humans, glucose is metabolized by glycolysis

respiratory chain to water and carbon dioxide. If there is not enough oxygen available for this, the glucose degradation in animals occurs anaerobic to lactate via lactic acid fermentation and releases much less energy. Muscular lactate enters the liver through the bloodstream in mammals, where gluconeogenesis occurs (Cori cycle). With a high supply of glucose, the metabolite acetyl-CoA from the Krebs cycle can also be used for fatty acid synthesis.[94] Glucose is also used to replenish the body's glycogen stores, which are mainly found in liver and skeletal muscle. These processes are hormonally
regulated.

In other living organisms, other forms of fermentation can occur. The bacterium

Use of glucose as an energy source in cells is by either aerobic respiration, anaerobic respiration, or fermentation.[96] The first step of glycolysis is the phosphorylation of glucose by a hexokinase to form glucose 6-phosphate. The main reason for the immediate phosphorylation of glucose is to prevent its diffusion out of the cell as the charged phosphate group prevents glucose 6-phosphate from easily crossing the cell membrane.[96] Furthermore, addition of the high-energy phosphate group activates glucose for subsequent breakdown in later steps of glycolysis.[97] At physiological conditions, this initial reaction is irreversible.[medical citation needed]

In anaerobic respiration, one glucose molecule produces a net gain of two ATP molecules (four ATP molecules are produced during glycolysis through substrate-level phosphorylation, but two are required by enzymes used during the process).[98] In aerobic respiration, a molecule of glucose is much more profitable in that a maximum net production of 30 or 32 ATP molecules (depending on the organism) is generated.[99]

Click on genes, proteins and metabolites below to link to respective articles.[§ 1]

[[File:
GlycolysisGluconeogenesis_WP534go to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to WikiPathwaysgo to articlego to Entrezgo to article
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
[[
]]
GlycolysisGluconeogenesis_WP534go to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to articlego to WikiPathwaysgo to articlego to Entrezgo to article
|alt=Glycolysis and Gluconeogenesis edit]]
Glycolysis and Gluconeogenesis edit
  1. ^ The interactive pathway map can be edited at WikiPathways: "GlycolysisGluconeogenesis_WP534".

Tumor cells often grow comparatively quickly and consume an above-average amount of glucose by glycolysis,[100] which leads to the formation of lactate, the end product of fermentation in mammals, even in the presence of oxygen. This is called the Warburg effect. For the increased uptake of glucose in tumors various SGLT and GLUT are overly produced.[101][102]

In yeast, ethanol is fermented at high glucose concentrations, even in the presence of oxygen (which normally leads to respiration rather than fermentation). This is called the Crabtree effect.

Glucose can also degrade to form carbon dioxide through abiotic means. This has been demonstrated to occur experimentally via oxidation and hydrolysis at 22 °C and a pH of 2.5.[103]

Energy source

Diagram showing the possible intermediates in glucose degradation; Metabolic pathways orange: glycolysis, green: Entner-Doudoroff pathway, phosphorylating, yellow: Entner-Doudoroff pathway, non-phosphorylating

Glucose is a ubiquitous fuel in

NADPH as a reductant for anabolism that would otherwise have to be generated indirectly.[107]

Glucose and oxygen supply almost all the energy for the

glucose is low, psychological processes requiring mental effort (e.g., self-control, effortful decision-making) are impaired.[109][110][111][112] In the brain, which is dependent on glucose and oxygen as the major source of energy, the glucose concentration is usually 4 to 6 mM (5 mM equals 90 mg/dL),[71] but decreases to 2 to 3 mM when fasting.[113] Confusion occurs below 1 mM and coma at lower levels.[113]

The glucose in the blood is called

Artificial sweeteners do not lower blood sugar levels.[115]

The blood sugar content of a healthy person in the short-time fasting state, e.g. after overnight fasting, is about 70 to 100 mg/dL of blood (4 to 5.5 mM). In

hypoglycaemia.[118] When needed, glucose is released into the bloodstream by glucose-6-phosphatase from glucose-6-phosphate originating from liver and kidney glycogen, thereby regulating the homeostasis of blood glucose concentration.[88][70] In ruminants, the blood glucose concentration is lower (60 mg/dL in cattle and 40 mg/dL in sheep), because the carbohydrates are converted more by their gut microbiota into short-chain fatty acids.[119]

Some glucose is converted to

brain cells; some glucose is used by intestinal cells and red blood cells, while the rest reaches the liver, adipose tissue and muscle cells, where it is absorbed and stored as glycogen (under the influence of insulin). Liver cell glycogen can be converted to glucose and returned to the blood when insulin is low or absent; muscle cell glycogen is not returned to the blood because of a lack of enzymes. In fat cells, glucose is used to power reactions that synthesize some fat
types and have other purposes. Glycogen is the body's "glucose energy storage" mechanism, because it is much more "space efficient" and less reactive than glucose itself.

As a result of its importance in human health, glucose is an analyte in

The

area under the curve of blood glucose levels after consumption in comparison to glucose (glucose is defined as 100).[122] The clinical importance of the glycemic index is controversial,[122][123] as foods with high fat contents slow the resorption of carbohydrates and lower the glycemic index, e.g. ice cream.[123] An alternative indicator is the insulin index,[124] measured as the impact of carbohydrate consumption on the blood insulin levels. The glycemic load
is an indicator for the amount of glucose added to blood glucose levels after consumption, based on the glycemic index and the amount of consumed food.

Precursor

Organisms use glucose as a precursor for the synthesis of several important substances. Starch, cellulose, and glycogen ("animal starch") are common glucose polymers (polysaccharides). Some of these polymers (starch or glycogen) serve as energy stores, while others (cellulose and chitin, which is made from a derivative of glucose) have structural roles. Oligosaccharides of glucose combined with other sugars serve as important energy stores. These include lactose, the predominant sugar in milk, which is a glucose-galactose disaccharide, and sucrose, another disaccharide which is composed of glucose and fructose. Glucose is also added onto certain proteins and lipids in a process called glycosylation. This is often critical for their functioning. The enzymes that join glucose to other molecules usually use phosphorylated glucose to power the formation of the new bond by coupling it with the breaking of the glucose-phosphate bond.

Other than its direct use as a monomer, glucose can be broken down to synthesize a wide variety of other biomolecules. This is important, as glucose serves both as a primary store of energy and as a source of organic carbon. Glucose can be broken down and converted into

glycosidases
.

Pathology

Diabetes

levels of glucose in the blood either because of a lack of insulin in the body or the failure, by cells in the body, to respond properly to insulin. Each of these situations can be caused by persistently high elevations of blood glucose levels, through pancreatic burnout and insulin resistance. The pancreas is the organ responsible for the secretion of the hormones insulin and glucagon.[126] Insulin is a hormone that regulates glucose levels, allowing the body's cells to absorb and use glucose. Without it, glucose cannot enter the cell and therefore cannot be used as fuel for the body's functions.[127] If the pancreas is exposed to persistently high elevations of blood glucose levels, the insulin-producing cells
in the pancreas could be damaged, causing a lack of insulin in the body. Insulin resistance occurs when the pancreas tries to produce more and more insulin in response to persistently elevated blood glucose levels. Eventually, the rest of the body becomes resistant to the insulin that the pancreas is producing, thereby requiring more insulin to achieve the same blood glucose-lowering effect, and forcing the pancreas to produce even more insulin to compete with the resistance. This negative spiral contributes to pancreatic burnout, and the disease progression of diabetes.

To monitor the body's response to blood glucose-lowering therapy, glucose levels can be measured. Blood glucose monitoring can be performed by multiple methods, such as the fasting glucose test which measures the level of glucose in the blood after 8 hours of fasting. Another test is the 2-hour glucose tolerance test (GTT) – for this test, the person has a fasting glucose test done, then drinks a 75-gram glucose drink and is retested. This test measures the ability of the person's body to process glucose. Over time the blood glucose levels should decrease as insulin allows it to be taken up by cells and exit the blood stream.

Hypoglycemia management

Glucose, 5% solution for infusions

Individuals with diabetes or other conditions that result in low blood sugar often carry small amounts of sugar in various forms. One sugar commonly used is glucose, often in the form of glucose tablets (glucose pressed into a tablet shape sometimes with one or more other ingredients as a binder), hard candy, or sugar packet.

Sources

Glucose tablets

Most dietary carbohydrates contain glucose, either as their only building block (as in the polysaccharides starch and glycogen), or together with another monosaccharide (as in the hetero-polysaccharides sucrose and lactose).[128] Unbound glucose is one of the main ingredients of honey. Glucose is extremely abundant and has been isolated from a variety of natural sources across the world, including male cones of the coniferous tree Wollemia nobilis in Rome,[129] the roots of Ilex asprella plants in China,[130] and straws from rice in California.[131]

Sugar content of selected common plant foods (in grams per 100 g)[132]
Food
item
Carbohydrate,
total,[a] including
dietary fiber
Total
sugars
Free
fructose
Free
glucose
Sucrose Ratio of
fructose/
glucose
Sucrose as
proportion of
total sugars (%)
Fruits
Apple 13.8 10.4 5.9 2.4 2.1 2.0 19.9
Apricot 11.1 9.2 0.9 2.4 5.9 0.7 63.5
Banana 22.8 12.2 4.9 5.0 2.4 1.0 20.0
Fig, dried 63.9 47.9 22.9 24.8 0.9 0.93 0.15
Grapes 18.1 15.5 8.1 7.2 0.2 1.1 1
Navel orange
12.5 8.5 2.25 2.0 4.3 1.1 50.4
Peach 9.5 8.4 1.5 2.0 4.8 0.9 56.7
Pear 15.5 9.8 6.2 2.8 0.8 2.1 8.0
Pineapple 13.1 9.9 2.1 1.7 6.0 1.1 60.8
Plum 11.4 9.9 3.1 5.1 1.6 0.66 16.2
Vegetables
Beet
, red
9.6 6.8 0.1 0.1 6.5 1.0 96.2
Carrot 9.6 4.7 0.6 0.6 3.6 1.0 77
Red pepper, sweet 6.0 4.2 2.3 1.9 0.0 1.2 0.0
Onion, sweet 7.6 5.0 2.0 2.3 0.7 0.9 14.3
Sweet potato 20.1 4.2 0.7 1.0 2.5 0.9 60.3
Yam 27.9 0.5 Traces Traces Traces Traces
Sugar cane
13–18 0.2–1.0 0.2–1.0 11–16 1.0 high
Sugar beet 17–18 0.1–0.5 0.1–0.5 16–17 1.0 high
Grains
Corn, sweet 19.0 6.2 1.9 3.4 0.9 0.61 15.0
  1. ^ The carbohydrate value is calculated in the USDA database and does not always correspond to the sum of the sugars, the starch, and the "dietary fiber".

Commercial production

Glucose is produced industrially from starch by

acids. Enzymatic hydrolysis has largely displaced acid-catalyzed hydrolysis reactions.[133] The result is glucose syrup (enzymatically with more than 90% glucose in the dry matter)[133] with an annual worldwide production volume of 20 million tonnes (as of 2011).[134] This is the reason for the former common name "starch sugar". The amylases most often come from Bacillus licheniformis[135] or Bacillus subtilis (strain MN-385),[135] which are more thermostable than the originally used enzymes.[135][136] Starting in 1982, pullulanases from Aspergillus niger were used in the production of glucose syrup to convert amylopectin to starch (amylose), thereby increasing the yield of glucose.[137] The reaction is carried out at a pH = 4.6–5.2 and a temperature of 55–60 °C.[11] Corn syrup has between 20% and 95% glucose in the dry matter.[138][139] The Japanese form of the glucose syrup, Mizuame, is made from sweet potato or rice starch.[140] Maltodextrin
contains about 20% glucose.

Many crops can be used as the source of starch.

invert sugar, a roughly 1:1 mixture of glucose and fructose that is produced from sucrose. In principle, cellulose could be hydrolyzed to glucose, but this process is not yet commercially practical.[54]

Conversion to fructose

In the US, almost exclusively corn (more precisely, corn syrup) is used as glucose source for the production of

isoglucose, which is a mixture of glucose and fructose, since fructose has a higher sweetening power – with same physiological calorific value of 374 kilocalories per 100 g. The annual world production of isoglucose is 8 million tonnes (as of 2011).[134] When made from corn syrup, the final product is high-fructose corn syrup
(HFCS).

Commercial usage

Relative sweetness of various sugars in comparison with sucrose[142]

Glucose is mainly used for the production of fructose and of glucose-containing foods. In foods, it is used as a sweetener, humectant, to increase the volume and to create a softer mouthfeel.[133] Various sources of glucose, such as grape juice (for wine) or malt (for beer), are used for fermentation to ethanol during the production of alcoholic beverages. Most soft drinks in the US use HFCS-55 (with a fructose content of 55% in the dry mass), while most other HFCS-sweetened foods in the US use HFCS-42 (with a fructose content of 42% in the dry mass).[143] In Mexico, on the other hand, soft drinks are sweetened by cane sugar, which has a higher sweetening power.[144] In addition, glucose syrup is used, inter alia, in the production of confectionery such as candies, toffee and fondant.[145] Typical chemical reactions of glucose when heated under water-free conditions are caramelization and, in presence of amino acids, the Maillard reaction.

In addition, various organic acids can be biotechnologically produced from glucose, for example by fermentation with

Propionibacter shermanii for the production of propionic acid, with Pseudomonas aeruginosa for the production of pyruvic acid and with Gluconobacter suboxydans for the production of tartaric acid.[146][additional citation(s) needed] Potent, bioactive natural products like triptolide that inhibit mammalian transcription via inhibition of the XPB subunit of the general transcription factor TFIIH has been recently reported as a glucose conjugate for targeting hypoxic cancer cells with increased glucose transporter expression.[147] Recently, glucose has been gaining commercial use as a key component of "kits" containing lactic acid and insulin intended to induce hypoglycemia and hyperlactatemia to combat different cancers and infections.[148]

Analysis

When a glucose molecule is to be detected at a certain position in a larger molecule, nuclear magnetic resonance spectroscopy, X-ray crystallography analysis or lectin immunostaining is performed with concanavalin A reporter enzyme conjugate, which binds only glucose or mannose.

Classical qualitative detection reactions

These reactions have only historical significance:

Fehling test

The

Fehling test is a classic method for the detection of aldoses.[149] Due to mutarotation, glucose is always present to a small extent as an open-chain aldehyde. By adding the Fehling reagents (Fehling (I) solution and Fehling (II) solution), the aldehyde group is oxidized to a carboxylic acid
, while the Cu2+ tartrate complex is reduced to Cu+ and forms a brick red precipitate (Cu2O).

Tollens test

In the

Tollens test, after addition of ammoniacal AgNO3 to the sample solution, glucose reduces Ag+ to elemental silver.[150]

Barfoed test

In

copper acetate, sodium acetate and acetic acid is added to the solution of the sugar to be tested and subsequently heated in a water bath for a few minutes. Glucose and other monosaccharides rapidly produce a reddish color and reddish brown copper(I) oxide
(Cu2O).

Nylander's test

As a reducing sugar, glucose reacts in the Nylander's test.[152]

Other tests

Upon heating a dilute

stannous chloride.[153] In an ammoniacal silver solution, glucose (as well as lactose and dextrin) leads to the deposition of silver. In an ammoniacal lead acetate solution, white lead glycoside is formed in the presence of glucose, which becomes less soluble on cooking and turns brown.[153] In an ammoniacal copper solution, yellow copper oxide hydrate is formed with glucose at room temperature, while red copper oxide is formed during boiling (same with dextrin, except for with an ammoniacal copper acetate solution).[153] With Hager's reagent, glucose forms mercury oxide during boiling.[153] An alkaline bismuth solution is used to precipitate elemental, black-brown bismuth with glucose.[153] Glucose boiled in an ammonium molybdate solution turns the solution blue. A solution with indigo carmine and sodium carbonate destains when boiled with glucose.[153]

Instrumental quantification

Refractometry and polarimetry

In concentrated solutions of glucose with a low proportion of other carbohydrates, its concentration can be determined with a polarimeter. For sugar mixtures, the concentration can be determined with a refractometer, for example in the Oechsle determination in the course of the production of wine.

Photometric enzymatic methods in solution

The enzyme glucose oxidase (GOx) converts glucose into gluconic acid and hydrogen peroxide while consuming oxygen. Another enzyme, peroxidase, catalyzes a chromogenic reaction (Trinder reaction)

4-aminoantipyrine to a purple dye.[155]

Photometric test-strip method

The test-strip method employs the above-mentioned enzymatic conversion of glucose to gluconic acid to form hydrogen peroxide. The reagents are immobilised on a polymer matrix, the so-called test strip, which assumes a more or less intense color. This can be measured reflectometrically at 510 nm with the aid of an LED-based handheld photometer. This allows routine blood sugar determination by nonscientists. In addition to the reaction of phenol with 4-aminoantipyrine, new chromogenic reactions have been developed that allow photometry at higher wavelengths (550 nm, 750 nm).[155][156]

Amperometric glucose sensor

The electroanalysis of glucose is also based on the enzymatic reaction mentioned above. The produced hydrogen peroxide can be amperometrically quantified by anodic oxidation at a potential of 600 mV.[157] The GOx is immobilized on the electrode surface or in a membrane placed close to the electrode. Precious metals such as platinum or gold are used in electrodes, as well as carbon nanotube electrodes, which e.g. are doped with boron.[158] Cu–CuO nanowires are also used as enzyme-free amperometric electrodes, reaching a detection limit of 50 μmol/L.[159] A particularly promising method is the so-called "enzyme wiring", where the electron flowing during the oxidation is transferred via a molecular wire directly from the enzyme to the electrode.[160]

Other sensory methods

There are a variety of other chemical sensors for measuring glucose.[161][162] Given the importance of glucose analysis in the life sciences, numerous optical probes have also been developed for saccharides based on the use of boronic acids,[163] which are particularly useful for intracellular sensory applications where other (optical) methods are not or only conditionally usable. In addition to the organic boronic acid derivatives, which often bind highly specifically to the 1,2-diol groups of sugars, there are also other probe concepts classified by functional mechanisms which use selective glucose-binding proteins (e.g. concanavalin A) as a receptor. Furthermore, methods were developed which indirectly detect the glucose concentration via the concentration of metabolized products, e.g. by the consumption of oxygen using fluorescence-optical sensors.[164] Finally, there are enzyme-based concepts that use the intrinsic absorbance or fluorescence of (fluorescence-labeled) enzymes as reporters.[161]

Copper iodometry

Glucose can be quantified by copper iodometry.[165]

Chromatographic methods

In particular, for the analysis of complex mixtures containing glucose, e.g. in honey, chromatographic methods such as

high performance liquid chromatography and gas chromatography[165] are often used in combination with mass spectrometry.[166][167] Taking into account the isotope ratios, it is also possible to reliably detect honey adulteration by added sugars with these methods.[168] Derivatization using silylation reagents is commonly used.[169]
Also, the proportions of di- and trisaccharides can be quantified.

In vivo analysis

Glucose uptake in cells of organisms is measured with

fluorodeoxyglucose.[113] (18F)fluorodeoxyglucose is used as a tracer in positron emission tomography in oncology and neurology,[170] where it is by far the most commonly used diagnostic agent.[171]

References

  1. ^ Nomenclature of Carbohydrates (Recommendations 1996) | 2-Carb-2 Archived 2023-08-27 at the Wayback Machine. iupac.qmul.ac.uk.
  2. ^
  3. ^ Ponomarev VV, Migarskaya LB (1960), "Heats of combustion of some amino-acids", Russ. J. Phys. Chem. (Engl. Transl.), 34: 1182–83
  4. .
  5. ^ a b "NCATS Inxight Drugs — DEXTROSE, UNSPECIFIED FORM". Archived from the original on 2023-12-11. Retrieved 2024-03-18.
  6. . Retrieved 13 May 2021.
  7. ^ a b c d "L-glucose". Biology Articles, Tutorials & Dictionary Online. 2019-10-07. Archived from the original on 2022-05-25. Retrieved 2022-05-06.
  8. ^ . WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO.
  9. ^ "Online Etymology Dictionary". Etymonline.com. Archived from the original on 2016-11-26. Retrieved 2016-11-25.
  10. ^ Thénard, Gay-Lussac, Biot, and Dumas (1838) "Rapport sur un mémoire de M. Péligiot, intitulé: Recherches sur la nature et les propriétés chimiques des sucres". Archived 2015-12-06 at the Wayback Machine (Report on a memoir of Mr. Péligiot, titled: Investigations on the nature and chemical properties of sugars), Comptes rendus, 7 : 106–113. From page 109. Archived 2015-12-06 at the Wayback Machine: "Il résulte des comparaisons faites par M. Péligot, que le sucre de raisin, celui d'amidon, celui de diabètes et celui de miel ont parfaitement la même composition et les mêmes propriétés, et constituent un seul corps que nous proposons d'appeler Glucose (1). ... (1) γλευχος, moût, vin doux." It follows from the comparisons made by Mr. Péligot, that the sugar from grapes, that from starch, that from diabetes and that from honey have exactly the same composition and the same properties, and constitute a single substance that we propose to call glucose (1) ... (1) γλευχος, must, sweet wine.
  11. ^ from the original on 2018-02-23.
  12. ^ Marggraf (1747) "Experiences chimiques faites dans le dessein de tirer un veritable sucre de diverses plantes, qui croissent dans nos contrées" Archived 2016-06-24 at the Wayback Machine [Chemical experiments made with the intention of extracting real sugar from diverse plants that grow in our lands], Histoire de l'académie royale des sciences et belles-lettres de Berlin, pp. 79–90. From page 90: Archived 2014-10-27 at the Wayback Machine "Les raisins secs, etant humectés d'une petite quantité d'eau, de maniere qu'ils mollissent, peuvent alors etre pilés, & le suc qu'on en exprime, etant depuré & épaissi, fournira une espece de Sucre." (Raisins, being moistened with a small quantity of water, in a way that they soften, can be then pressed, and the juice that is squeezed out, [after] being purified and thickened, will provide a sort of sugar.)
  13. . p. 7.
  14. from the original on 2019-12-17. Retrieved 2019-07-01.
  15. ^ Emil Fischer, Nobel Foundation, archived from the original on 2009-09-03, retrieved 2009-09-02
  16. ^ Fraser-Reid B, "van't Hoff's Glucose", Chem. Eng. News, 77 (39): 8
  17. ^ "Otto Meyerhof - Facts - NobelPrize.org" Archived 2018-07-15 at the Wayback Machine. NobelPrize.org. Retrieved on 5 September 2018.
  18. ^ "Hans von Euler-Chelpin - Facts - NobelPrize.org" Archived 2018-09-03 at the Wayback Machine. NobelPrize.org. Retrieved on 5 September 2018.
  19. ^ "Arthur Harden - Facts - NobelPrize.org" Archived 2018-09-03 at the Wayback Machine. NobelPrize.org. Retrieved on 5 September 2018.
  20. ^ "Bernardo Houssay - Facts - NobelPrize.org" Archived 2018-07-15 at the Wayback Machine. NobelPrize.org. Retrieved on 5 September 2018.
  21. ^ "Carl Cori - Facts - NobelPrize.org" Archived 2018-07-15 at the Wayback Machine. NobelPrize.org. Retrieved on 5 September 2018.
  22. ^ "Gerty Cori - Facts - NobelPrize.org" Archived 2018-07-15 at the Wayback Machine. NobelPrize.org. Retrieved on 5 September 2018.
  23. ^ "Luis Leloir - Facts - NobelPrize.org" Archived 2018-07-15 at the Wayback Machine. NobelPrize.org. Retrieved on 5 September 2018.
  24. .
  25. ^ "glucose." The Columbia Encyclopedia, 6th ed.. 2015. Encyclopedia.com. 17 Nov. 2015 http://www.encyclopedia.com Archived 2009-04-26 at the Wayback Machine.
  26. .
  27. .
  28. from the original on 2021-04-14. Retrieved 2024-03-18.
  29. from the original on 2024-02-12. Retrieved 2024-03-18.
  30. .
  31. ^ "Potentially Important Contribution of Dextrose Used as Diluent to Hyperglycemia in Hospitalized Patients | Diabetes Care | American Diabetes Association". Archived from the original on 2022-05-29. Retrieved 2024-03-18.
  32. ^ "Dextrose: Why is it in food and medicine?". 24 June 2018. Archived from the original on 13 February 2024. Retrieved 18 March 2024.
  33. ^ a b c "What is Dextrose, How is It Used, and is It Healthy? - the Nutrition Insider". 27 October 2023. Archived from the original on 14 February 2024. Retrieved 18 March 2024.
  34. ^ "Dextrose vs. Glucose: Are These Sugars Equal?". Archived from the original on 2023-09-29. Retrieved 2024-03-18.
  35. PMID 938892
    .
  36. ^ a b c d "Prakash Chemicals International". Archived from the original on 2023-06-06. Retrieved 2024-03-18.
  37. ^ "API | glucose monohydrate". Archived from the original on 2023-03-24. Retrieved 2024-03-18.
  38. ^ a b c d "The difference between dextrose anhydrous and dextrose monohydrate". 28 December 2022. Archived from the original on 18 March 2024. Retrieved 18 March 2024.
  39. ^ "Dextrose anhydrous". Archived from the original on 2024-03-18. Retrieved 2024-03-18.
  40. from the original on 2024-03-18. Retrieved 2024-03-18.
  41. ^ a b "What is the difference between anhydrous glucose and glucose". Archived from the original on 2024-03-18. Retrieved 2024-03-18.
  42. ^ "Anhydrous vs. Monohydrate - What's the Difference?". Archived from the original on 2024-03-18. Retrieved 2024-03-18.
  43. from the original on 18 March 2024. Retrieved 18 March 2024.
  44. from the original on 2024-03-18. Retrieved 2024-03-18.
  45. ^ "Diabetes & Prediabetes Tests - NIDDK". Archived from the original on 2023-12-16. Retrieved 2024-03-18.
  46. ^ "Dextrose Monohydrate". Archived from the original on 2023-12-02. Retrieved 2024-03-18.
  47. ^ "Archived copy". Archived from the original on 2024-03-18. Retrieved 2024-03-18.{{cite web}}: CS1 maint: archived copy as title (link)
  48. ^ "D-Glucose". Archived from the original on 2023-12-15. Retrieved 2024-03-18.
  49. ^ "Archived copy". Archived from the original on 2024-03-18. Retrieved 2024-03-18.{{cite web}}: CS1 maint: archived copy as title (link)
  50. ^ "Archived copy". Archived from the original on 2024-03-18. Retrieved 2024-03-18.{{cite web}}: CS1 maint: archived copy as title (link)
  51. ^ "Glucose (Dextrose)". 2 October 2013. Archived from the original on 21 December 2023. Retrieved 18 March 2024.
  52. ^ .
  53. ^ . p. 316.
  54. , Volume 1, p. 76.
  55. ^ "16.4: Cyclic Structures of Monosaccharides". Chemistry LibreTexts. 2014-07-18. Archived from the original on 2023-04-17. Retrieved 2023-04-17.
  56. .
  57. .
  58. .
  59. .
  60. ^ , p. 34 (in German).
  61. ^ .
  62. , p. 531. (German)
  63. ^ .
  64. ^ .
  65. p. 228.
  66. ^ a b "Chemistry for Biologists: Photosynthesis". www.rsc.org. Archived from the original on 2016-08-04. Retrieved 2018-02-05.
  67. ^ , p. 195. (German)
  68. ^ . p. 674.
  69. .
  70. ISSN 0095-8301, archived from the original
    on 2013-10-14, retrieved 2010-05-20
  71. from the original on 2016-12-06.
  72. ^ "Showing Compound D-Glucose (FDB012530) - FooDB". Archived from the original on 2022-12-06. Retrieved 2024-03-18.
  73. ^ , p. 404.
  74. , p. 641. (in German)
  75. .
  76. ^ , p. 199, 200. (in German)
  77. (PDF) from the original on 2023-12-02. Retrieved 2024-03-18.
  78. ^ , p. 214. (in German)
  79. .
  80. .
  81. .
  82. .
  83. .
  84. .
  85. ^ , p. 46.
  86. , p. 389. (in German)
  87. from the original on 2024-03-18. Retrieved 2021-11-09.
  88. .
  89. ; p. 490–496. (German)
  90. ^ , p. 164.
  91. .
  92. .
  93. ^ (PDF) from the original on 2017-03-06. Retrieved March 5, 2017.
  94. ^ "Glucose". Archived from the original on 2023-12-05. Retrieved 2024-03-18.
  95. from the original on 2018-02-23
  96. from the original on 2018-02-23
  97. .
  98. .
  99. .
  100. from the original on 2024-03-18. Retrieved 2021-11-09.
  101. from the original on 2010-05-24
  102. , p. 100 (in German).
  103. ^ Schmidt, Lang: Physiologie des Menschen, 30. Auflage. Springer Verlag, 2007, p. 907 (in German).
  104. PMID 10493919
    .
  105. ^ Dash P. "Blood Brain Barrier and Cerebral Metabolism (Section 4, Chapter 11)". Neuroscience Online: An Electronic Textbook for the Neurosciences. Department of Neurobiology and Anatomy – The University of Texas Medical School at Houston. Archived from the original on 2016-11-17.
  106. S2CID 44500072
  107. (PDF) from the original on 2017-08-18
  108. ^ , p. XIII.
  109. ^ .
  110. ^
    S2CID 38764657. Archived from the original
    on 2020-07-29. Retrieved 2020-06-07.
  111. ..
  112. .
  113. , p. 927, 985 (in German).
  114. , p. 294.
  115. .
  116. ^ "Diagnosing Diabetes and Learning About Prediabetes". American Diabetes Association. Archived from the original on 2017-07-28. Retrieved 2018-02-20.
  117. ^ , p. 366.
  118. ^ , p. 508.
  119. .
  120. ^ , p. 27. (in German)
  121. .
  122. ^ Estela, Carlos (2011) "Blood Glucose Levels," Undergraduate Journal of Mathematical Modeling: One + Two: Vol. 3: Iss. 2, Article 12.
  123. ^ "Carbohydrates and Blood Sugar". The Nutrition Source. 2013-08-05. Archived from the original on 2017-01-30. Retrieved 2017-01-30 – via Harvard T.H. Chan School of Public Health.
  124. from the original on 2024-03-18. Retrieved 2021-11-11.
  125. from the original on 2024-03-18. Retrieved 2021-11-11.
  126. from the original on 2024-03-18, retrieved 2021-11-11
  127. ^ "FoodData Central". fdc.nal.usda.gov. Archived from the original on 2019-12-03. Retrieved 2024-03-18.
  128. ^ , p. 197.
  129. ^ . Volume 6, p. 48.
  130. ^ , p. 195.
  131. .
  132. .
  133. .
  134. . Retrieved 25 November 2016.
  135. .
  136. , p. 527.
  137. ^ "Sugar". Learning, Food Resources. food.oregonstate.edu. Oregon State University, Corvallis, OR. 2012-05-23. Archived from the original on 2011-07-18. Retrieved 2018-06-28.
  138. ^ "High Fructose Corn Syrup: Questions and Answers". US Food and Drug Administration. 2014-11-05. Archived from the original on 2018-01-25. Retrieved 2017-12-18.
  139. Seattle Times
    , October 29, 2004.
  140. , p. 82.
  141. , p. 938.
  142. .
  143. .
  144. ^ H. Fehling: Quantitative Bestimmung des Zuckers im Harn. In: Archiv für physiologische Heilkunde (1848), volume 7, p. 64–73 (in German).
  145. Berichte der Deutschen Chemischen Gesellschaft
    (1882), volume 15, p. 1635–1639 (in German).
  146. from the original on 2020-07-29. Retrieved 2019-07-01.
  147. Zeitschrift für physiologische Chemie. Volume 8, Issue 3, 1884, p. 175–185 Abstract. Archived 2015-09-23 at the Wayback Machine
    (in German).
  148. ^ , p. 102 (in German).
  149. .
  150. ^ from the original on 2024-03-18. Retrieved 2024-03-18.
  151. .
  152. ..
  153. .
  154. .
  155. .
  156. ^ .
  157. .
  158. .
  159. .
  160. ^ .
  161. .
  162. ^ Max Planck Institute of Molecular Plant Physiology in Golm Database (2007-07-19). "Glucose mass spectrum". Golm Metabolome Database. Archived from the original on 2018-09-09. Retrieved 2018-06-04.
  163. PMID 17177492
    .
  164. .
  165. , February 2000.
  166. .