Search results
Results from the WOW.Com Content Network
The energy released by this highly exergonic oxidation reaction drives the endergonic second reaction (ΔG°'=+50 kJ/mol (+12kcal/mol)), in which a molecule of inorganic phosphate is transferred to the GAP intermediate to form a product with high phosphoryl-transfer potential: 1,3-bisphosphoglycerate (1,3-BPG).
Phosphorylation is essential to the processes of both anaerobic and aerobic respiration, which involve the production of adenosine triphosphate (ATP), the "high-energy" exchange medium in the cell. During aerobic respiration, ATP is synthesized in the mitochondrion by addition of a third phosphate group to adenosine diphosphate (ADP) in a ...
In the glycolytic pathway, 1,3-BPG is the phosphate donor and has a high phosphoryl-transfer potential. The PGK-catalyzed transfer of the phosphate group from 1,3-BPG to ADP to yield ATP can power [clarification needed] the carbon-oxidation reaction of the previous glycolytic step (converting glyceraldehyde 3-phosphate to 3-phosphoglycerate).
Phosphoryl groups are transferred during PEPCK action, which is likely facilitated by the eclipsed conformation of the phosphoryl groups when ATP is bound to PEPCK. [ 11 ] Since the eclipsed formation is one that is high in energy, phosphoryl group transfer has a decreased energy of activation , meaning that the groups will transfer more readily.
It was found that an enzyme, named phosphorylase kinase and Mg-ATP were required to phosphorylate glycogen phosphorylase by assisting in the transfer of the γ-phosphoryl group of ATP to a serine residue on phosphorylase b. Protein phosphatase 1 is able to catalyze the dephosphorylation of phosphorylated enzymes by removing the phosphate group.
Substrate-velocity relationships and induced transport tests have revealed that the dephosphorylated enzyme then facilitates the transfer of a phosphoryl group from the glucose-1,6-bisphosphate intermediate to the enzyme, regenerating phosphorylated phosphoglucomutase and yielding glucose 6-phosphate (in the forward direction).
Phosphoryl transfer only occurs on closing of the 'open lid'. This causes an exclusion of water molecules that brings the substrates in proximity to each other, [ 7 ] lowering the energy barrier for the nucleophilic attack by the α-phosphoryl of AMP on the γ-phosphoryl group of ATP resulting in formation of ADP by transfer of the γ ...
Substrate-level phosphorylation exemplified with the conversion of ADP to ATP. Substrate-level phosphorylation is a metabolism reaction that results in the production of ATP or GTP supported by the energy released from another high-energy bond that leads to phosphorylation of ADP or GDP to ATP or GTP (note that the reaction catalyzed by creatine kinase is not considered as "substrate-level ...