Gluconeogenesis (De Novo Synthesis of Glucose)

Gluconeogenesis (De Novo Synthesis of Glucose)

Glucose is a source of energy for the mammalian cells whose concentration is narrowly managed in their body while during the fasting stage this range is nearly dropped to the  3.9–5.6 mmol/L. So, the liver shift its metabolism towards gluconeogenesis to balance the euglycemia.....
During the prolonged period of fasting, the shift towards the gluconeogensis is compulsion because it can be critical for neurons, medullary cells of kidney, and RBCs that solely use glucose for energy (1).

As Reversal of Glycolysis

Gluconeogenesis is reversal of glycolysis. The non-carbohydrates molecules like amino acids, lactate and glycerol can be converted into pyruvate, then enters into mitochondria and is carboxylated to OAA. Here, OAA is converted into malate and entered into the cytoplasm and again re-oxidized into OAA, which ultimately decarboxylated and then phosphorylated to phosphoenelpyruvate (PEP). Then, PEP enters into the gluconeogenic cycle with the reversal of 4 important key enzymes including PC, PEPCk, FBPase, and G6Pase.


Gluconeogenesis (Reversal of Glycolysis)

Adipose tissues releases glycerol into the plasma taken up by the liver and here it is converted into Dihydroxyacetone phosphate (DHAP), which is then changes to G-3-P or F-1,6-BP, and enters into gluconeogenic cycle. 


Summative Cycles for Gluconeogenesis





 



Enzymes of Gluconeogenic Cycle

For reversal of glycolysis irreversible enzymes, 4 gluconeogenesis enzymes including PC, PEPCK, FBPase and G6Pase plays important roles. 




References

1. Shah, A., & Wondisford, F. E. (2023). Gluconeogenesis flux in metabolic disease. Annual Review of Nutrition, 43(1), 153-177.

Comments

Post a Comment

Popular posts from this blog

kEY IRREVERSIBLE REACTIONS OF GLYCOLYSIS REACTIONS

Image
 What is Glycolysis? Glycolysis or Embden–Meyerhof–Parnas pathway was the first pathway elucidated. Meyerhof won the noble prize in 1922 in physiology and medicine for his discovery to find fixed relationship between lactic acid utilisation in muscles and expenditure of oxygen (1). The word glycolysis is derived from Greek word "glykys" means sweet (Old Greek: γλυκύς, glykys, ‘sweet) and "lysis" means splitting (Old Greek: λύσις, lysis). So, the glycolysis involves the splitting of 1 glucose molecule into 2 pyruvate molecules. Moving on the pyruvate have two fate, whether converted into the acetyl-CO-A in the presence of oxygen or Lactate in the absence of oxygen (1).   Brief Summary  Summarising the glycolysis, it involves the 10 reactions that take place in cytosol and generate 2 ATP molecules. Despite taking place in the cytosol, yet evolved even before oxygen was present in the Earth's atmosphere.  Irreversible Reactions of Glycolysis Three irreversible reac...
Read more

Chromatography Techniques

Chromatography is termed as the technique through which a complex mixture of chemical components are separated, identified and determined. The compounds obtained have high grade purity and components of a mixture are separated based on the rates through which they move the stationary phase (column) by a gaseous or liquid mobile phase. Column Chromatography A type of adsorption chromatography and separate the compounds on the basis of polarity or hydrophobicity. In a classical column chromatography, a stationary phase consist on a glass column packed with silica accompanied by packing of sludge (the mixture of sample to be separated adsorbed in silica). In a carbon column chromatography (CCC), an adsorbent other than silica, activated carbon, porous graphitic-carbon, and activated carbon combined with poly-urethane foam, glass fiber, silica gel, celite, and Chromosorb W-HP can be used.  Importance: An eluent of mobile phase is poured into column, and eluate is collected at the botto...
Read more