Watch the F1 component of the ATP Synthase molecule make ATP. The rotational force produce by the F0 component (not seen here) allows the rotation of the gamma component to move similar to a cam-shaft on an auto. This rotation allows the F1 component to open and close. The action of the opening and closing allows the ADP and Pi to enter, be brought into proximity and joined to make ATP. Watch the sequence.
Electron transport chain associates electron carriers (such as NADH and FADH2) and mediating biochemical reactions that produce adenosine triphosphate (ATP), which is a major energy intermediate in living organisms. Only two sources of energy are available to biosynthesize organic molecules and maintain biochemical and kinetic processes in living organisms: oxidation-reduction (redox) reactions and some forms of radiation, such as sunlight (used for photosynthesis). Organisms that use redox reactions to produce ATP are called chemotrophs. Organisms that use sunlight are called phototrophs. Both chemotrophs and phototrophs use electron transport chains to convert energy into ATP. This is achieved through a three-step process:
Gradually sap energy from high-energy electrons in a series of individual steps.
Use that energy to forcibly unbalance the proton concentration across the membrane, creating an electrochemical gradient.
Use the energy released by the drive to re-balance the proton distribution as a means of producing ATP.
The Electron Transport Chain is also called the ETC. ATP is made by an enzyme called ATP Synthase. The structure of this enzyme and its underlying genetic code is remarkably conserved in all known forms of life.
ATP synthase is powered by a transmembrane electrochemical potential gradient, usually in the form of a proton gradient. The function of the electron transport chain is to produce this gradient. In all living organisms, a series of redox reactions is used to produce a transmembrane electrochemical potential gradient.
Redox reactions are chemical reactions in which electrons are transferred from a donor molecule to an acceptor molecule. The underlying force driving these reactions is the Gibbs free energy of the reactants and products. The Gibbs free energy is the energy available ("free") to do work. Any reaction that decreases the overall Gibbs free energy of a system will proceed spontaneously.
The transfer of electrons from a high-energy molecule (the donor) to a lower-energy molecule (the acceptor) can be spatially separated into a series of intermediate redox reactions. This is an electron transport chain.
The fact that a reaction is thermodynamically possible does not mean that it will actually occur; for example, a mixture of hydrogen gas and oxygen gas does not spontaneously ignite. It is necessary either to supply an activation energy or to lower the intrinsic activation energy of the system, in order to make most biochemical reactions proceed at a useful rate. Living systems use complex macromolecular structures (enzymes) to lower the activation energies of biochemical reactions.
It is possible to couple a thermodynamically favorable reaction (a transition from a high-energy state to a lower-energy state) to a thermodynamically unfavorable reaction (such as a separation of charges, or the creation of an osmotic gradient), in such a way that the overall free energy of the system decreases (making it thermodynamically possible), while useful work is done at the same time. Biological macromolecules that catalyze a thermodynamically unfavorable reaction if and only if a thermodynamically favorable reaction occurs simultaneously underlie all known forms of life.
Electron transport chains capture energy in the form of a transmembrane electrochemical potential gradient. This energy can then be harnessed to do useful work. The gradient can be used to transport molecules across membranes. It can be used to do mechanical work, such as rotating bacterial flagella. It can be used to produce ATP high-energy molecules that are necessary for growth.
A small amount of ATP is available from substrate-level phosphorylation (for example, in glycolysis). Some organisms can obtain ATP exclusively by fermentation. In most organisms, however, the majority of ATP is generated by electron transport chains.
Definition Calvin cycle is a biochemical reaction takes place in Stroma of the chloroplasts in photosynthetic plants,it was discovered by Melvin Calvin,Bassham and Andrew Benson at the University of California, Berkeley.
Energy from light are stored has ATP and NADPH .in Calvin cycle this stored energy is used to make sugar molecule, the Calvin cycle is a complex theory of chemical reactions carried out in stroma.
The Calvin cycle begins with the input of CO2, three molecules are carbon dioxide added to three molecules of 5 carbon sugar abbreviated RUBP, this molecules are rearranged to become 6 molecules of 3-PGA which have 3 carbons each, note the molecules are not actually rearranged .in the next two reactions product from light reaction are used to boost energy of these 3 carbon moelcules.First high energy phosphate groups are added 6 ATP molecules contribute phosphate groups so each 3carbon molecule receives a additional phosphate group ,electrons are added in next reaction 6 molecules of NADPH are oxidized electron in NADPH reduce the 6 3 carbon compounds creating 6 high energy G3P molecule G3P is a sugar the final product of Calvin cycle ,one of G3p molecule represents the 3 carbon dioxide molecules fixed so far the other 5 G3P molecules are reshuffled to regenerate the original RUBP molecules .To summaries so far the Calvin cycle used the energy of the light reaction to reduce 3 molecules of carbon dioxide and produce 1 molecule of G3P , 3 more carbon-dioxide molecules are fixed to form G3P in the same complicated way ,to make each G3P the Calvin cycle consumes 9 ATP molecules and 6 NADPH molecules ,these are regenerated in Light reaction ,G3p is actual final product of the Calvin cycle the cell combine 2 G3Ps to make Glucose which stores the energy
