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Showing 31 - 40 of 605359 pathways
SMPDB ID Pathway Name and Description Pathway Class Chemical Compounds Proteins


Pw000163 View Pathway

Tryptophan Metabolism

This pathway depicts the metabolic reactions and pathways associated with tryptophan metabolism in animals. Tryptophan is an essential amino acid. This means that it cannot be synthesized by humans and other mammals and therefore must be part of the diet. Unlike animals, plants and microbes can synthesize tryptophan from shikimic acid or anthranilate. As one of the 20 proteogenic amino acids, tryptophan plays an important role in protein biosynthesis through the action of tryptophanyl-tRNA synthetase. As shown in this pathway, tryptophan can be linked to the tryptophanyl-tRNA via either the mitochondrial or cytoplasmic tryptophan tRNA ligases. Also shown in this pathway map is the conversion of tryptophan to serotonin (a neurotransmitter). In this process, tryptophan is acted upon by the enzyme tryptophan hydroxylase, which produces 5-hydroxytryptophan (5HTP). 5HTP is then converted into serotonin (5-HT) via aromatic amino acid decarboxylase. Serotonin, in turn, can be converted into N-acetyl serotonin (via serotonin-N-acetyltransferase) and then melatonin (a neurohormone), via 5-hydroxyindole-O-methyltransferase. The melatonin can be converted into 6-hydroxymelatonin via the action of cytochrome P450s in the endoplasmic reticulum. Serotonin has other fates as well. As depicted in this pathway it can be converted into N-methylserotonin via Indolethylamine-N-methyltransferase (INMT) or it can be converted into formyl-5-hydroxykynurenamine via indoleamine 2,3-dioxygenase. Serotonin may also be converted into 5-methoxyindoleacetate via a series of intermediates including 5-hydroxyindoleacetaldehyde and 5-hydroxyindoleacetic acid. Tryptophan can be converted or broken down into many other compounds as well. It can be converted into tryptamine via the action of aromatic amino acid decarboxylase. The resulting tryptamine can then be converted into indoleacetaldehyde via kynurenine 3-monooxygenase and then into indoleacetic acid via the action of aldehyde dehydrogenase. Tryptophan also leads to the production of a very important compound known as kynurenine. Kynurenine is synthesized via the action of tryptophan 2,3-dioxygnase, which produces N-formylkynurenine. This compound is converted into kynurenine via the enzyme known as kynurenine formamidase (AFMID). Kynurenine has at least 3 fates. First, kynurenine can undergo deamination in a standard transamination reaction yielding kynurenic acid. Secondly, kynurenine can undergo a series of catabolic reactions (involving kynureninase and kynurenine 3-monooxygenase) producing 3-hydroxyanthranilate plus alanine. In this reaction, kynureninase catabolizes the conversion of kynurenine into anthranilic acid while kynurenine—oxoglutarate transaminase (also known as kynurenine aminotransferase or glutamine transaminase K, GTK) catabolizes its conversion into kynurenic acid. The action of kynurenine 3-hydroxylase on kynurenic acid leads to 3-hydroxykynurenine. The oxidation of 3-hydroxyanthranilate converts it into 2-amino-3-carboxymuconic 6-semialdehyde, which has two fates. It can either degrade to form acetoacetate or it can cyclize to form quinolate. Most of the body’s 3-hydroxyanthranilate leads to the production of acetoacetate (a ketone body), which is why tryptophan is also known as a ketogenic amino acid. An important side reaction in the liver involves a non-enzymatic cyclization into quinolate followed by transamination and several rearrangements to yield limited amounts of nicotinic acid, which leads to the production of a small amount of NAD+ and NADP+.


Pw000151 View Pathway

Nicotinate and Nicotinamide Metabolism

Nicotinate (niacin) and nicotinamide - more commonly known as vitamin B3 - are precursors of the coenzymes nicotinamide-adenine dinucleotide (NAD+) and nicotinamide-adenine dinucleotide phosphate (NADP+). NAD+ synthesis occurs either de novo from amino acids, or a salvage pathway from nicotinamide. Most organisms use the de novo pathway whereas the savage pathway is only typically found in mammals. The specifics of the de novo pathway varies between organisms, but most begin by forming quinolinic acid (QA) from tryptophan (Trp) in animals, or aspartic acid in some bacteria (intestinal microflora) and plants. Nicotinate-nucleotide pyrophosphorylase converts QA into nicotinic acid mononucleotide (NaMN) by transfering a phosphoribose group. Nicotinamide mononucleotide adenylyltransferase then transfers an adenylate group to form nicotinic acid adenine dinucleotide (NaAD). Lastly, the nicotinic acid group is amidated to form a nicotinamide group, resulting in a molecule of nicotinamide adenine dinucleotide (NAD). Additionally, NAD can be phosphorylated to form NADP. The salvage pathway involves recycling nicotinamide and nicotinamide-containing molecules such as nicotinamide riboside. The precursors are fed into the NAD+ biosynthetic pathwaythrough adenylation and phosphoribosylation reactions. These compounds can be found in the diet, where the mixture of nicotinic acid and nicotinamide are called vitamin B3 or niacin. These compounds are also produced within the body when the nicotinamide group is released from NAD+ in ADP-ribose transfer reactions.


Pw000024 View Pathway

Folate Metabolism

Folate, or folic acid, is a very important B-vitamin involved in cell creation and preservation, as well as the protection of DNA from mutations that can cause cancer. It is commonly found in leafy green vegetables, but is also present in many other foods such as fruit, dairy products, eggs and meat. Folate is imperative during pregnancy as a deficiency will cause neural tube defects in the offspring. Many countries around the world now fortify foods with folic acid to prevent such defects. This pathway begins in the extracellular space, where folic acid is transported into the cell through a proton-coupled folate transporter. From there, dihydrofolate reductase converts folic acid into dihydrofolic acid. Dihydrofolic acid is then created into tetrahydrofolic acid through dihydrofolate reductase. Tetrahydrofolic acid then sparks the beginning of many reactions and subpathways including purine metabolism and histidine metabolism. There are two reactions that tetrahydrofolic acid undergoes, the first being the catalyzation into tetrahydrofolyl-[glu](2) through the enzyme folylpolyglutamate synthase in the mitochondria. Then, tetrahydrofolyl-[glu](2) becomes tetrahydrofolyl-[glu](n) through folylpolyglutamate synthase. The cycle ends with tetrahydrofolyl-[glu](n) reverting to tetrahydrofolyl-[glu](2) in the lysosome through the enzyme gamma-glutamyl hydrolase. The second reaction that begins with tetrahydrofolic acid sees tetrahydrofolic acid turned into 10-formyltetrahydrofolate through c-1-tetrahydrofolate synthase. This loop is completed by cytosolic 10-formyltetrahydrofolate dehydrogenase reverting 10-formyltetrahydrofolate back to tetrahydrofolic acid. Folate is not stored in the body for very long, as it is a water soluble vitamin and is excreted through urine, so it is important to ingest it continually, as your body’s level of folate will decline after a few weeks if the vitamin is avoided.


Pw000043 View Pathway

Histidine Metabolism

Histidine, an amino acid, plays an important role in the creation of proteins. It is unique as an amino acid as it is needed for nucleotide formation. The biosynthesis of histidine in adults begins with the condensation of ATP and PRPP (phosphoribosyl pyrophosphate) to form n-5-phosphoribosyl 1-pyrophosphate (phosphoribosyl-ATP). It is also worth noting that PRPP is the beginning compound for purine and pyrimidine creation. Subsequent histidine biosynthetic steps (from phosphoribosyl-ATP onwards) are likely to occur in the intestinal microflora. Elimination of the phosphate and the opening of the ring in phosphoribosyl-ATP forms phosphoribosyl-forminino-5-aminoimidazole-4-carboxamide ribonucleotide(phosphoribosyl-forminino-AICAR-phosphate). This is subsequently converted to 5-phosphoribulosyl-forminino-5-aminoimidazole-4-carboxamide ribonucleotide. Cleavage of this compound creates imidazole glycerol phosphate and AICAR (aminoimidazolecarboxamide ribonucleotide) with glutamine being involved as an amino group donor. AICAR is used again through the purine pathway while the imidazole glycerol phosphate is converted to imidazole acetal phosphate. Transamination yields histidinol phosphate which is then turned into histidinol, and then, finally, to histidine. L-histidine is catalyzed by histidine ammonia-lyase into urocanic acid. This acid is then converted to 4-imidazolone-5-propionic acid by urocanate hydratase. 4-imidazolone-5-propionic acid is then converted to formiminoglutamic acid, using the enzyme probable imidazolonepropionase. One last reaction occurs to allow for glutamate metabolism, as formiminoglutamic acid is converted to l-glutamic acid through the use of formimidoyltransferase-cyclodeaminase. Histidine is also a precursor for carnosine biosynthesis(via carnosine synthase), with beta-alanine being the rate limiting precursor. Anserine can be synthesized either from carnosine via carnosine N-methyltransferase or from 1-methylhistidine via carnosine synthase. Inversely, cytosolic non-specific dipeptidase catalyzes the synthesis of 1-methylhistidine from anserine. Histidine is found in meat, seeds, nuts and whole grains. It is a very important amino acid in keeping a pH of 7 in the body, as it acts as a shuttle for protons to maintain a balance of acids and bases in the blood and different tissues.


Pw000005 View Pathway

Citric Acid Cycle

The citric acid cycle, which is also known as the tricarboxylic acid cycle (TCA cycle) or the Krebs cycle, is a connected series of enzyme-catalyzed chemical reactions of central importance to all aerobic organisms (i.e. organisms that use oxygen for cellular respiration). The citric acid cycle is named after citrate or citric acid, a tricarboxylic acid that is both consumed and regenerated through this pathway. The citric acid cycle was discovered in 1937 by Hans Adolf Krebs while he worked at the University of Sheffield in England (PMID: 16746382). Krebs received the Nobel Prize for his discovery in 1953. Krebs’ extensive work on this pathway is also why the citric acid or TCA cycle is often referred to as the Krebs cycle. Metabolically, the citric acid cycle allows the release of energy (ultimately in the form of ATP) from carbohydrates, fats, and proteins through the oxidation of acetyl-CoA. The citric acid cycle also produces CO2, the precursors for several amino acids (aspartate, asparagine, glutamine, proline) and NADH – all of which are used in other important metabolic pathways, such as amino acid synthesis and oxidative phosphorylation (OxPhos). The net yield of one “turn” of the TCA cycle in terms of energy-containing compounds is one GTP, one FADH2, and three NADH molecules. The NADH molecules are used in oxidative phosphorylation to generate ATP. In eukaryotes, the citric acid cycle occurs in the mitochondrial matrix. In prokaryotes, the citric acid cycle occurs in the cytoplasm. In eukaryotes, the citric acid or TCA cycle has a total of 10 steps that are mediated by 8 different enzymes. Key to the whole cycle is the availability of acetyl-CoA. One of the primary sources of acetyl-CoA is from the breakdown of glucose (and other sugars) by glycolysis. This process generates pyruvate. Pyruvate is decarboxylated by pyruvate dehydrogenase to generate acetyl-CoA. The citric acid cycle begins with acetyl-CoA transferring its two-carbon acetyl group to the four-carbon acceptor compound (oxaloacetate) to form a six-carbon compound (citrate) through the enzyme citrate synthase. The resulting citrate is then converted to cis-aconitate and then isocitrate via the enzyme aconitase. The resulting isocitrate then combines with NAD+ to form oxalosuccinate and NADH, which is then converted into alpha-ketoglutarate (and CO2) through the action of the enzyme known as isocitrate dehydrogenase. The resulting alpha-ketoglutarate combines with NAD+ and CoA-SH to produce succinyl-CoA, NADH, and CO2. This step is mediated by the enzyme alpha-ketoglutarate dehydrogenase. The resulting succinyl-CoA combines with GDP and organic phosphate to produce succinate, CoA-SH, and GTP. This phosphorylation reaction is performed by succinyl-CoA synthase. The resulting succinate then combines with ubiquinone to produce two compounds, fumarate and ubiquinol through the action of the enzyme succinate dehydrogenase. The resulting fumarate is then hydrated by the enzyme known as fumarase to produce malate. The resulting malate is oxidized via NAD+ to produce oxaloacetate and NADH. This oxidation reaction is performed by malate dehydrogenase. The resulting oxaloacetate can then combine with acetyl-CoA and the TCA reaction cycle begins again. Overall, in the citric acid cycle, the starting six-carbon citrate molecule loses two carboxyl groups as CO2, leading to the production of a four-carbon oxaloacetate. The two-carbon acetyl-CoA that is the “fuel” for the TCA cycle can be generated by several metabolic pathways including glucose metabolism, fatty acid oxidation, and the metabolism of amino acids. The overall reaction for the citric acid cycle is as follows: acetyl-CoA + 3 NAD+ + FAD + GDP + P + 2H2O = CoA-SH + 3NADH + FADH2 + 3H+ + GTP + 2CO2. Many molecules in the citric acid cycle serve as key precursors for other molecules needed by cells. The citrate generated via the citric acid cycle can serve as an intermediate for fatty acid synthesis; alpha-ketoglutarate can serve as a precursor for glutamate, proline, and arginine; oxaloacetate can serve as a precursor for aspartate and asparagine; succinyl-CoA can serve as a precursor for porphyrins; and acetyl-CoA can serve as a precursor fatty acids, cholesterol, vitamin D, and various steroid hormones. There are several variations to the citric acid cycle that are known. Interestingly, most of the variation lies with the step involving succinyl-CoA production or conversion. Humans and other animals have two different types of succinyl-CoA synthetases. One produces GTP from GDP, while the other produces ATP from ADP (PMID: 9765291). On the other hand, plants have a succinyl-CoA synthetase that produces ATP (ADP-forming succinyl-CoA synthetase) (Jones RC, Buchanan BB, Gruissem W. (2000). Biochemistry & molecular biology of plants (1st ed.). Rockville, Md: American Society of Plant Physiologists. ISBN 0-943088-39-9.). In certain acetate-producing bacteria, such as Acetobacter aceti, an enzyme known as succinyl-CoA:acetate CoA-transferase performs this conversion (PMID: 18502856) while in Helicobacter pylori succinyl-CoA:acetoacetate CoA-transferase is responsible for this reaction (PMID: 9325289). The citric acid cycle is regulated in a number of ways but the primary mechanism is by product inhibition. For instance, NADH inhibits pyruvate dehydrogenase, isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, and citrate synthase. Acetyl-CoA inhibits pyruvate dehydrogenase, while succinyl-CoA inhibits alpha-ketoglutarate dehydrogenase and citrate synthase. Additionally, ATP inhibits citrate synthase and alpha-ketoglutarate dehydrogenase. Calcium is another important regulator of the citric acid cycle. In particular, it activates pyruvate dehydrogenase phosphatase, which then activates pyruvate dehydrogenase. Calcium also activates isocitrate dehydrogenase and alpha-ketoglutarate dehydrogenase (PMID: 171557).


Pw000144 View Pathway

Glycerolipid Metabolism

The glycerolipid metabolism pathway describes the synthesis of glycerolipids such as monoacylglycerols (MAGs), diacylglycerols (DAGs), triacylglycerols (TAGs), phosphatidic acids (PAs), and lysophosphatidic acids (LPAs). The process begins with cytoplasmic 3-phosphoglyceric acid (a product of glycolysis). This molecule is dephosphorylated via the enzyme glycerate kinase to produce glyceric acid. Glyceric acid is then transformed to glycerol (via the action of aldehyde dehydrogenase and aldose reductase). The free, cytoplasmic glycerol can then be phosphorylated to glycerol-3-phosphate through the action of glycerol kinase. Glycerol-3-phosphate can then enter the endoplasmic reticulum where glycerol-3-phosphate acyltransferase (GPAT) may combine various acyl-CoA moieties (which donate acyl groups) to form lysophosphatidic (LPA) or phosphatidic acid (PA). The resulting phosphatidic acids can be dephosphorylated via lipid phosphate phosphohydrolase (also known as phosphatidate phosphatase) to produce diacylglycerols (DAGs). The resulting DAGs can be converted into triacylglycerols (TAGs) via the addition of another acyl group (contributed via acyl-CoA) and the action of 1-acyl-sn-glycerol-3-phosphate acyltransferase. Extracellularly, the triacylglycerols (TAGs) can be converted to monoacylglycerols (MAGs) through the action of hepatic triacylglycerol lipase. In addition to this cytoplasmic route of glycerolipid synthesis, another route via mitochondrial synthesis also exists. This route begins with glycerol-3-phosphate, which can be either derived from dihydroxyacetone phosphate (DHAP), a product of glycolysis (usually in the cytoplasm of liver or adipose tissue cells) or from glycerol itself. Glycerol-3-phosphate in the mitochondria is first acylated via acyl-coenzyme A (acyl-CoA) through the action of mitochondrial glycerol-3-phosphate acyltransferase to form lysophosphatidic acid (LPA). Once synthesized, lysophosphatidic acid is then acylated with another molecule of acyl-CoA via the action of 1-acyl-sn-glycerol-3-phosphate acetyltransferase to yield phosphatidic acid. Phosphatidic acid is then dephosphorylated to form diacylglycerol. Specifically, diacylglycerol is formed by the action of phosphatidate phosphatase (also known as lipid phosphate phosphohydrolase) on phosphatidic acid coupled with the release of a phosphate. The phosphatase exists as 3 isozymes. Diacylglycerol is a precursor to triacylglycerol (triglyceride), which is formed in the addition of a third fatty acid to the diacylglycerol by the action of diglyceride acyltransferase. Since diacylglycerol is synthesized via phosphatidic acid, it will usually contain a saturated fatty acid at the C-1 position on the glycerol moiety and an unsaturated fatty acid at the C-2 position. When the body uses stored fat as a source of energy, glycerol and fatty acids are released into the bloodstream. Fatty acids, stored as triglycerides in humans, are an important and a particularly rich source of energy. The energy yield from a gram of fatty acids is approximately 9 kcal/g (39 kJ/g), compared to 4 kcal/g (17 kJ/g) for carbohydrates. Since the hydrocarbon portion of fatty acids is hydrophobic, these molecules can be stored in a relatively anhydrous (water-free) environment. Fatty acids can hold more than six times the amount of energy than sugars on a weight basis. In other words, if you relied on sugars or carbohydrates to store energy, then you would need to carry 67.5 lb (31 kg) of glycogen to have the energy equivalent to 10 lb (5 kg) of fat.


Pw000036 View Pathway

Thiamine Metabolism

Thiamine, (Vitamin B1), is a compound found in many different foods such as beans, seafood, meats and yogurt. It is usually maintained by the consumption of whole grains. It is an essential part of energy metabolism. This means that thiamine helps convert carbohydrates into energy. Eating carbohydrates increases the need for this vitamin, as your body can only store about 30mg at a time due to the vitamins short half-life. Thiamine was first synthesized in 1936, which was very helpful in researching its properties in relation to beriberi, a vitamin b1 deficiency. This deficiency has been observed mainly in countries where rice is the staple food. Thiamine metabolism begins in the extracellular space, being transported by a thiamine transporter into the cell. Once in the intracellular space, thiamine is converted into thiamine pyrophosphate through the enzyme thiamin pyrophosphate kinase 1. Thiamine pyrophosphate is then converted into thiamine triphosphate, again using the enzyme thiamin pyrophosphatekinase 1. After this, thiamine triphosphate uses thiamine-triphosphatase to revert to thiamine pyrophosphate, which undergoes a reaction using cancer-related nuceloside-triphosphatase to become thiamine monophosphate. This phosphorylated form is a metabolically active form of thiamine, as are the two other compounds, derivatives of thiamine, mentioned previously. The enzymes used in this pathway both stem from the upper small intestine. Thiamine is passed mainly through urine. It is a water-soluble vitamin, which means it dissolves in water and is carried to different parts of the body but is not stored in the body.


Pw000050 View Pathway

Steroid Biosynthesis

The steroid biosynthesis (or cholesterol biosynthesis) pathway is an anabolic metabolic pathway that produces steroids from simple precursors. It starts with the mevalonate pathway, where acetyl-CoA and acetoacetyl-CoA are the first two building blocks. These compounds are joined together via the enzyme hydroxy-3-methylgutaryl (HMG)-CoA synthase to produce the compound known as hydroxy-3-methylgutaryl-CoA (HMG-CoA). This compound is then reduced to mevalonic acid via the enzyme HMG-CoA reductase. It is important to note that HMG-CoA reductase is the protein target of many cholesterol-lowering drugs called statins (PMID: 12602122). The resulting mevalonic acid (or mevalonate) is then phosphorylated by the enzyme known as mevalonate kinase to form mevalonate-5-phosphate, which is then phosphorylated again by phosphomevalonate kinase to form mevolonate-5-pyrophsophate. This pyrophosphorylated compound is subsequently decarboxylated via the enzyme mevolonate-5-pyrophsophate decarboxylase to form isopentylpyrophosphate (IPP). IPP can also be isomerized (via isopentenyl-PP-isomerase) to form dimethylallylpyrophosphate (DMAPP). IPP and DMAPP can both donate isoprene units, which can then be joined together to make farnesyl and geranylgeranyl intermediates. Specifically, three molecules of IPP condense to form farnesyl pyrophosphate through the action of the enzyme known as geranyl transferase. Two molecules of farnesyl pyrophosphate then condense to form a molecule known as squalene by the action of the enzyme known as squalene synthase in the cell’s endoplasmic reticulum. The enzyme oxidosqualene cyclase then cyclizes squalene to form lanosterol. Lanosterol is a tetracyclic triterpenoid, and serves as the framework from which all steroids are derived. 14-Demethylation of lanosterol by a cytochrome P450 enzyme known as CYP51 eventually yields cholesterol. Cholesterol is the central steroid in human biology. It can be obtained from animal fats consumed in the diet or synthesized de novo (as described above). Cholesterol is an essential constituent of lipid bilayer membranes (where it forms cholesterol esters) and is the starting point for the biosynthesis of steroid hormones, bile acids and bile salts, and vitamin D. Steroid hormones are mostly synthesized in the adrenal gland and gonads. They regulate energy metabolism and stress responses (via glucocorticoids such as cortisol), salt balance (mineralocorticoids such as aldosterone), and sexual development and function (via androgens such as testosterone and estrogens such as estradiol). Bile acids and bile salts (such as taurocholate) are mostly synthesized in the liver. They are released into the intestine and function as detergents to solubilize dietary fats. Cholesterol is the main constituent of atheromas. These are the fatty lumps found in the walls of arteries that occur in atherosclerosis and, when ruptured, can cause heart attacks.


Pw000012 View Pathway

Betaine Metabolism

Betaine (or trimethylglycine) is similar to choline (trimethylaminoethanol) but differs in choline's terminal carboxylic acid group trimethylglycine is reduced to a hydroxyl group. Betaine is obtained from diet as betaine or compounds containing choline in foods such as whole grains, beets and spinach. Betaine can also be synthesized from choline in the liver and kidney. First, choline is oxidized to betaine aldehyde by mitochondrial choline oxidase (choline dehydrogenase). Then, betaine aldehyde dehydrogenase oxidizes betaine aldehyde to betaine in the mitochondria or cytoplasm. In the liver, betaine functions as a methyl donor similar to choline, folic acid, S-adenosyl methionine and vitamin B12. Methyl donors are important for liver function, cellular replication and detoxification reactions. Betaine is also involved in the production of carnitine to protect from kidney damage and functions as an osmoprotectant in the inner medulla.


Pw000055 View Pathway

Pentose Phosphate Pathway

The pentose phosphate pathway—also referred to in the literature as the phosphogluconate pathway, the hexose monophosphate shunt, or the pentose phosphate shunt—is involved in the generation of NADPH as well as pentose sugars. Of the total cytoplasmic NADPH used in biosynthetic reactions, a significant proportion of it is generated through the pentose phosphate pathway. Ribose 5-phosphate is also another essential product generated by this pathway which is employed in nucleotide synthesis. The pentose phosphate pathway is also involved in the digestive process as the products of nucleic acid catabolism can be metabolized through the pathway (pentose sugars are usually yielded in the breakdown) while the carbon backbones of dietary carbohydrates can be converted into glycolytic/gluconeogenic intermediates. The pentose phosphate pathway is interconnected to the glycolysis pathway through the shared use of three intermediates: glucose 6-phosphate, glyceraldehyde 3-phosphate, and fructose 6-phosphate. The pathway can be described as eight distinct reactions (see below) and is separated into an oxidative phase and a non-oxidative phase. Reactions 1-3 form the oxidative phase and generate NADPH and pentose 5-phosphate. Reactions 4-8 form the non-oxidative phase and converts pentose 5-phosphate into other pentose sugars such as ribose 5-phosphate, but generates no NADPH. The eight reactions are as follows: reaction 1 where glucose-6-phosphate 1-dehydrogenase converts glucose 6-phosphate into D-glucono-1,5-lactone 6-phosphate with NADPH formation; reaction 2 where 6-phosphogluconolactonase converts D-glucono-1,5-lactone 6-phosphate into 6-phospho-D-gluconate;reaction 3 where 6-phosophogluconate dehydrogenase converts 6-phospho-D-gluconate into ribulose 5-phosphate with NADPH formation; reaction 4 where ribulose-phosphate 3-epimerase converts ribulose 5-phosphate into xylulose 5-phosphate; reaction 5 where ribose-5-phosphate isomerase converts ribulose 5-phosphate into ribose 5-phosphate; reaction 6 where transketolase rearranges ribose 5-phosphate and xylulose 5-phosphate to form sedoheptulose 7-phosphate and glyceraldehyde 3-phosphate; reaction 7 where transaldolase rearranges of sedoheptulose 7-phosphate and glyceraldehyde 3-phosphate to form erythrose 4-phosphate and fructose 6-phosphate; and reaction 8 where transkelotase rearranges of xylulose 5-phosphate and erythrose 4-phosphate to form glyceraldehyde 3-phosphate and fructose-6-phosphate.
Showing 31 - 40 of 65006 pathways