Browsing Pathways

Glycerol metabolism starts with glycerol is introduced into the cytoplasm through a glycerol channel GlpF Glycerol is then phosphorylated through an ATP mediated glycerol kinase resulting in a Glycerol 3-phosphate. This compound can also be obtained through glycerophosphoglycerol reacting with water through a glycerophosphoryl diester phosphodiesterase producing a benzyl alcohol, a hydrogen ion and a glycerol 3-phosphate or the campound can be introduced into the cytoplasm through a glycerol-3-phosphate:phosphate antiporter. Glycerol 3-phosphate is then metabolized into a dihydroxyacetone phosphate in both aerobic or anaerobic conditions. In anaerobic conditions the metabolism is done through the reaction of glycerol 3-phosphate with a menaquinone mediated by a glycerol-3-phosphate dehydrogenase protein complex. In aerobic conditions, the metabolism is done through the reaction of glycerol 3-phosphate with ubiquinone mediated by a glycerol-3-phosphate dehydrogenase [NAD(P]+]. Dihydroxyacetone phosphate is then introduced into the fructose metabolism by turning a dihydroxyacetone into an isomer through a triosephosphate isomerase resulting in a D-glyceraldehyde 3-phosphate which in turn reacts with a phosphate through a NAD dependent Glyceraldehyde 3-phosphate dehydrogenase resulting in a glyceric acid 1,3-biphosphate. This compound is desphosphorylated by a phosphoglycerate kinase resulting in a 3-phosphoglyceric acid.This compound in turn can either react with a 2,3-bisphosphoglycerate-independent phosphoglycerate mutase or a 2,3-bisphosphoglycerate-independent phosphoglycerate mutase resulting in a 2-phospho-D-glyceric acid. This compound interacts with an enolase resulting in a phosphoenolpyruvic acid and water. Phosphoenolpyruvic acid can react either through a AMP driven phosphoenoylpyruvate synthase or a ADP driven pyruvate kinase protein complex resulting in a pyruvic acid. Pyruvic acid reacts with CoA through a NAD driven pyruvate dehydrogenase complex resulting in a carbon dioxide and a Acetyl-CoA which gets incorporated into the TCA cycle pathway.

Fatty acid metabolism is also known as beta-oxidation. During beta-oxidation, acetyl-CoA is produced which can be used in the citric acid cycle. When ATP is needed, ATP may be generated by increasing fatty acid metabolism. Therefore fatty acids constitute a large energy source for organisms since it can be a source of generated ATP when needed. Fatty acid metabolism is essentially the reverse reaction of fatty acid synthesis which is essential for cellular processes since the membrane is mostly made up of fatty acids.

Oxaloglycolate (2-Hydroxy-3-oxosuccinate) interacts with a tartrate dehydrogenase resulting in a L-tartrate. L-tartrate then interacts with tartrate dehydrogenase resulting in a Oxaloacetate. Oxaloacetate and acetyl-coa interact to result in a citrate which is processed by a aconitate hydratase resulting in a cis-Aconitate and further more into a isocitrate which will eventually be procressed into a glyoxylic acid. Glyoxylic acid can either be metabolized into L-malic acid by a reaction with acetyl-CoA and Water through a malate synthase G which also releases hydrogen ion and Coenzyme A. L-malic acid is then incorporated into the TCA cycle. Glyoxylic acid can also be metabolized by glyoxylate carboligase, releasing a carbon dioxide and tartronate semialdehyde. The latter compound is then reduced by an NADH driven tartronate semialdehyde reductase 2 resulting in glyceric acid. Glyceric acid is phosphorylated by a glycerate kinase 2 resulting in a 3-phosphoglyceric acid. This compound is then integrated into various other pathways: cysteine biosynthesis, serine biosynthesis and glycolysis and pyruvate dehydrogenase.

Ethylbenzene degradation involves a sequence of enzymatic activities that allow bacteria to use ethylbenzene as both a carbon and energy source. Due to its hydrophobic nature, ethylbenzene can enter bacterial cells via passive diffusion across the cell membrane. Once inside, the enzyme ethylbenzene dehydrogenase activates ethylbenzene, converting it to (S)-1-phenylethanol, which is then transformed to acetophenone by (S)-1-phenylethanol dehydrogenase. Acetophenone is further converted to Benzoylacetyl-CoA, which enters the benzoate degradation route, where energy is generated and different compounds, including folate, are synthesised.

Benzoate, an environmental pollutant, is utilized by bacteria such as Aromatoleum aromaticum to yield energy and carbon. While the precise transport mechanisms remain under research, it is proposed that benzoate is transported across the cell membrane passively or actively via transport proteins such as permeases and porins. Benzoate is then converted to benzoyl-CoA by benzoate-CoA ligase. Benzoyl-CoA then undergoes further degradation, catalyzed by enzymes like benzoyl-CoA reductase, leading to the formation of intermediate cyclohexane compounds which are ultimately converted into central metabolites that can enter the citrate cycle for further energy generation

Toluene degradation allows bacteria to use toluene, a common environmental pollutant, as both a carbon and energy source. Toluene enters the bacterial cell by passive diffusion due to its hydrophobic nature. Once within the cell, toluene undergoes a variety of enzymatic reactions. The first step is for the Gamma-Subunit of benzylsuccinate synthase to convert it into benzylsuccinate. This intermediate is then converted to Benzylsuccinyl-CoA by subunit of Benzylsuccinate CoA-transferases. Subsequently, Benzylsuccinyl-CoA undergoes a series of enzymatic reactions to form Benzoylsuccinyl-CoA, and finally benzoyl-CoA, which enters the benzoate degradation pathway, providing the bacteria with energy and carbon for growth and survival.

Fatty acid metabolism is also known as beta-oxidation. During beta-oxidation, acetyl-CoA is produced which can be used in the citric acid cycle. When ATP is needed, ATP may be generated by increasing fatty acid metabolism. Therefore fatty acids constitute a large energy source for organisms since it can be a source of generated ATP when needed. Fatty acid metabolism is essentially the reverse reaction of fatty acid synthesis which is essential for cellular processes since the membrane is mostly made up of fatty acids.

Ethylbenzene degradation involves a sequence of enzymatic activities that allow bacteria to use ethylbenzene as both a carbon and energy source. Due to its hydrophobic nature, ethylbenzene can enter bacterial cells via passive diffusion across the cell membrane. Once inside, the enzyme ethylbenzene dehydrogenase activates ethylbenzene, converting it to (S)-1-phenylethanol, which is then transformed to acetophenone by (S)-1-phenylethanol dehydrogenase. Acetophenone is further converted to Benzoylacetyl-CoA, which enters the benzoate degradation route, where energy is generated and different compounds, including folate, are synthesised.

Ethylbenzene degradation involves a sequence of enzymatic activities that allow bacteria to use ethylbenzene as both a carbon and energy source. Due to its hydrophobic nature, ethylbenzene can enter bacterial cells via passive diffusion across the cell membrane. Once inside, the enzyme ethylbenzene dehydrogenase activates ethylbenzene, converting it to (S)-1-phenylethanol, which is then transformed to acetophenone by (S)-1-phenylethanol dehydrogenase. Acetophenone is further converted to Benzoylacetyl-CoA, which enters the benzoate degradation route, where energy is generated and different compounds, including folate, are synthesised.

Phospholipids are membrane components in E. coli. The major phospholipids of E. coli are phosphatidylethanolamine, phosphatidylglycerol and cardiolipin. All phospholipids contain sn-glycerol-3-phosphate esterified with fatty acids at the sn-1 and sn-2 positions. The reaction starts from a glycerone phosphate (dihydroxyacetone phosphate) produced in glycolysis. The glycerone phosphate is transformed to a sn-glycerol 3-phosphate (glycerol 3 phosphate) by NADPH driven glycerol-3-phosphate dehydrogenase. Sn-glycerol 3-phosphate is transformed to a 1-acyl-sn-glycerol 3-phosphate(1-oleyl-2-lyso-phosphatidate , 1-palmitoylglycerol 3-phosphate , 1-stearoyl-sn-glycerol 3-phosphate). This can be achieve by a sn-glycerol-3-phosphate 1-0-acyltransferase that interacts either with a long-chain acyl-CoA or with an acyl-[acp]. The 1-acyl-sn-glycerol 3-phosphate is transformed into a 1,2-diacyl-sn-glycerol 3-phosphate through a 1-acylglycerol-3-phosphate O-acyltransferase. This compound is then converted into a CPD-diacylglycerol through a CTP (phosphatidate cytididyltransferase. CPD-diacylglycerol can be transformed either to a L-1-phosphatidylserine or a L-1-phosphatidylglycerol-phosphate through a phosphatidylserine synthase or a phosphatidylglycerophosphate synthase respectively. The L-1-phosphatidylserine transforms into L-1-phosphatidylethanolamine through a phosphatidylserine decarboxylase, o the other hand L-1-phosphatidylglycerol-phosphate gets transformed into a L-1-phosphatidyl-glycerol through a phosphatidylglycerophosphatase. These 2 products combines produce a cardiolipin and a ethanolamine. The L-1 phosphatidyl-glycerol can also interact with cardiolipin synthase resulting in a glycerol and a cardiolipin.