Search results
Results From The WOW.Com Content Network
The Phosphate (Pho) regulon is a regulatory mechanism used for the conservation and management of inorganic phosphate within the cell. It was first discovered in Escherichia coli as an operating system for the bacterial strain, and was later identified in other species. [ 1 ]
Phosphorylation allows cells to accumulate sugars because the phosphate group prevents the molecules from diffusing back across their transporter. Phosphorylation of glucose is a key reaction in sugar metabolism. The chemical equation for the conversion of D-glucose to D-glucose-6-phosphate in the first step of glycolysis is given by:
An estimated 1/10 to 1/2 of proteins are phosphorylated in some cellular state. 30–65% of proteins in humans and ~50% of proteins in yeast may be phosphorylated. [15] [2] An estimated 230,000, 156,000, and 40,000 phosphorylation sites exist in human, mouse, and yeast, respectively. [2]
In biochemistry, a kinase (/ ˈ k aɪ n eɪ s, ˈ k ɪ n eɪ s,-eɪ z /) [2] is an enzyme that catalyzes the transfer of phosphate groups from high-energy, phosphate-donating molecules to specific substrates. This process is known as phosphorylation, where the high-energy ATP molecule donates a phosphate group to the substrate molecule.
The phosphate ion has a molar mass of 94.97 g/mol, and consists of a central phosphorus atom surrounded by four oxygen atoms in a tetrahedral arrangement. It is the conjugate base of the hydrogen phosphate ion H(PO 4) 2−, which in turn is the conjugate base of the dihydrogen phosphate ion H 2 (PO 4) −
The hydrophilic end usually contains a negatively charged phosphate group, and the hydrophobic end usually consists of two "tails" that are long fatty acid residues. [ 4 ] In aqueous solutions, phospholipids are driven by hydrophobic interactions , which result in the fatty acid tails aggregating to minimize interactions with the water molecules.
EPSP synthase catalyzes the reaction which converts shikimate-3-phosphate plus phosphoenolpyruvate to 5-enolpyruvylshikimate-3-phosphate (EPSP) by way of an acetal-like tetrahedral intermediate. [ 9 ] [ 10 ] Basic and acidic amino acids in the active site are involved in deprotonation of the hydroxyl group of PEP and in the proton-exchange ...
Dephosphorylation involves removal of the phosphate group through a hydration reaction by addition of a molecule of water and release of the original phosphate group, regenerating the hydroxyl. Both processes are reversible and either mechanism can be used to activate or deactivate a protein.