Adenosine triphosphate: Difference between revisions
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[[Image:Adenosintriphosphat.svg.png|thumb]] | |||
'''Adenosine triphosphate (ATP)''' is used as a source of free energy to drive reactions in the cell. Hydrolysis of ATP is slow in the absence of catalysis. Enzymes couple ATP hydrolysis to reactions whose equilibrium lies on the side of the reactants. Enzymes that utilize ATP hydrolysis including motor proteins like myosin, ion pumps, and many biosynthetic enzymes. ATP also is the source of phosphate for many phosphorylation reactions. In eukaryotes, ATP is synthesized mainly in mitochondria (and chloroplasts in plants). | '''Adenosine triphosphate (ATP)''' is used as a source of free energy to drive reactions in the cell. Hydrolysis of ATP is slow in the absence of catalysis. Enzymes couple ATP hydrolysis to reactions whose equilibrium lies on the side of the reactants. Enzymes that utilize ATP hydrolysis including motor proteins like myosin, ion pumps, and many biosynthetic enzymes. ATP also is the source of phosphate for many phosphorylation reactions. In eukaryotes, ATP is synthesized mainly in mitochondria (and chloroplasts in plants). | ||
==Structure== | ==Structure== | ||
<StructureSection load='' size='340' side='right' caption='Caption for this structure' scene='82/824011/Atp_mg/ | <StructureSection load='' size='340' side='right' caption='Caption for this structure' scene='82/824011/Atp_mg/3'> | ||
ATP (reload <scene name='82/824011/Atp_mg/ | ATP (reload <scene name='82/824011/Atp_mg/3'>initial scene</scene>) contains a nitrogenous base (adenine <jmol><jmolLink><script> select ATP and base and not (_P or _O); selectionHalos ON; delay 0.5;selectionHalos OFF;</script><text>☼</text></jmolLink> </jmol>), a sugar (ribose <jmol><jmolLink><script> select ATP and not base; selectionHalos ON; delay 0.5;selectionHalos OFF;</script><text>☼</text></jmolLink> </jmol>) and the triphosphate group (<jmol><jmolLink><script> select base and (_P or _O); selectionHalos ON; delay 0.5;selectionHalos OFF;</script><text>☼</text></jmolLink> </jmol>). Within enzyme active sites, the beta and gamma phosphate groups often bind to a magnesium cation which helps negatively charged nucleophiles to approach the negatively charged triphosphate group. The most common <jmol><jmolLink><script> select ATP; wireframe off; select ADP; wireframe 0.3;delay 0.5; select ADP; wireframe off; select ATP; wireframe 0.3;</script><text>hydrolysis reaction of ATP</text></jmolLink> </jmol> yields ADP, but in some reactions the product is AMP. | ||
</StructureSection> | </StructureSection> | ||
== References == | == References == | ||
<references/> | <references/> | ||
Latest revision as of 07:37, 6 January 2020
Adenosine triphosphate (ATP) is used as a source of free energy to drive reactions in the cell. Hydrolysis of ATP is slow in the absence of catalysis. Enzymes couple ATP hydrolysis to reactions whose equilibrium lies on the side of the reactants. Enzymes that utilize ATP hydrolysis including motor proteins like myosin, ion pumps, and many biosynthetic enzymes. ATP also is the source of phosphate for many phosphorylation reactions. In eukaryotes, ATP is synthesized mainly in mitochondria (and chloroplasts in plants).
StructureStructure
ATP (reload ) contains a nitrogenous base (adenine ), a sugar (ribose ) and the triphosphate group (). Within enzyme active sites, the beta and gamma phosphate groups often bind to a magnesium cation which helps negatively charged nucleophiles to approach the negatively charged triphosphate group. The most common yields ADP, but in some reactions the product is AMP. |
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