Search results
Results from the WOW.Com Content Network
Structure of ATP Structure of ADP Four possible resonance structures for inorganic phosphate. ATP hydrolysis is the catabolic reaction process by which chemical energy that has been stored in the high-energy phosphoanhydride bonds in adenosine triphosphate (ATP) is released after splitting these bonds, for example in muscles, by producing work in the form of mechanical energy.
This process is related to osmosis, the movement of water across a selective membrane, which is why it is called "chemiosmosis". ATP synthase is the enzyme that makes ATP by chemiosmosis. It allows protons to pass through the membrane and uses the free energy difference to convert phosphorylate adenosine diphosphate (ADP) into ATP. The ATP ...
Steps 1 and 3 require the input of energy derived from the hydrolysis of ATP to ADP and P i (inorganic phosphate), whereas steps 7 and 10 require the input of ADP, each yielding ATP. [7] The enzymes necessary to break down glucose are found in the cytoplasm , the viscous fluid that fills living cells, where the glycolytic reactions take place.
The squiggle notation was invented by Fritz Albert Lipmann, who first proposed ATP as the main energy transfer molecule of the cell, in 1941. [4] Lipmann's notation emphasizes the special nature of these bonds. [5] Stryer states: ATP is often called a high energy compound and its phosphoanhydride bonds are referred to as high-energy bonds.
A notable occurrence of dephosphorylation is the conversion of ATP to ADP and inorganic phosphate. Dephosphorylation employs a type of hydrolytic enzyme, or hydrolase , which cleaves ester bonds. The prominent hydrolase subclass used in dephosphorylation is phosphatase , which removes phosphate groups by hydrolysing phosphoric acid monoesters ...
ATP synthase, also called complex V, is the final enzyme in the oxidative phosphorylation pathway. This enzyme is found in all forms of life and functions in the same way in both prokaryotes and eukaryotes. [67] The enzyme uses the energy stored in a proton gradient across a membrane to drive the synthesis of ATP from ADP and phosphate (P i).
At cytoplasmic conditions, where the ADP/ATP ratio is 10 orders of magnitude from equilibrium, the ΔG is around −57 kJ/mol. [12] Along with pH, the free energy change of ATP hydrolysis is also associated with Mg 2+ concentration, from ΔG°' = −35.7 kJ/mol at a Mg 2+ concentration of zero, to ΔG°' = −31 kJ/mol at [Mg 2+] = 5 mM.
The ATP-ADP translocase (also called adenine nucleotide translocase, ANT) is an antiporter and exchanges ADP and ATP across the inner membrane. The driving force is due to the ATP (−4) having a more negative charge than the ADP (−3), and thus it dissipates some of the electrical component of the proton electrochemical gradient.