Where is atp created

ATP is biosynthesized in several ways, as described by Biology Dictionary :. Photophosphorylation is a method specific to plants and cyanobacteria. ATP is also formed from the process of cellular respiration in the mitochondria of a cell. This can be through aerobic respiration, which requires oxygen, or anaerobic respiration, which does not.

Aerobic respiration produces ATP along with carbon dioxide and water from glucose and oxygen. Anaerobic respiration uses chemicals other than oxygen, and this process is primarily used by archaea and bacteria that live in anaerobic environments. Fermentation is another way of producing ATP that does not require oxygen; it is different from anaerobic respiration because it does not use an electron transport chain.

Yeast and bacteria are examples of organisms that use fermentation to generate ATP. ATP synthesized in mitochondria is the primary energy source for important biological functions, such as muscle contraction, nerve impulse transmission, and protein synthesis.

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Rather, a cell must be able to handle that energy in a way that enables the cell to store energy safely and release it for use only as needed. Living cells accomplish this by using the compound adenosine triphosphate ATP. It functions similarly to a rechargeable battery. When ATP is broken down, usually by the removal of its terminal phosphate group, energy is released. The energy is used to do work by the cell, usually by the released phosphate binding to another molecule, activating it.

For example, in the mechanical work of muscle contraction, ATP supplies the energy to move the contractile muscle proteins. Recall the active transport work of the sodium-potassium pump in cell membranes. ATP alters the structure of the integral protein that functions as the pump, changing its affinity for sodium and potassium. In this way, the cell performs work, pumping ions against their electrochemical gradients.

Figure 1. ATP adenosine triphosphate has three phosphate groups that can be removed by hydrolysis to form ADP adenosine diphosphate or AMP adenosine monophosphate. The negative charges on the phosphate group naturally repel each other, requiring energy to bond them together and releasing energy when these bonds are broken. At the heart of ATP is a molecule of adenosine monophosphate AMP , which is composed of an adenine molecule bonded to a ribose molecule and to a single phosphate group Figure 1.

The addition of a second phosphate group to this core molecule results in the formation of adenosine diphosphate ADP ; the addition of a third phosphate group forms adenosine triphosphate ATP.

The addition of a phosphate group to a molecule requires energy. Phosphate groups are negatively charged and thus repel one another when they are arranged in series, as they are in ADP and ATP.

The release of one or two phosphate groups from ATP, a process called dephosphorylation , releases energy. Hydrolysis is the process of breaking complex macromolecules apart.

Water, which was broken down into its hydrogen atom and hydroxyl group during ATP hydrolysis, is regenerated when a third phosphate is added to the ADP molecule, reforming ATP. Obviously, energy must be infused into the system to regenerate ATP. Where does this energy come from? In nearly every living thing on earth, the energy comes from the metabolism of glucose. In this way, ATP is a direct link between the limited set of exergonic pathways of glucose catabolism and the multitude of endergonic pathways that power living cells.

Recall that, in some chemical reactions, enzymes may bind to several substrates that react with each other on the enzyme, forming an intermediate complex. An intermediate complex is a temporary structure, and it allows one of the substrates such as ATP and reactants to more readily react with each other; in reactions involving ATP, ATP is one of the substrates and ADP is a product.

During an endergonic chemical reaction, ATP forms an intermediate complex with the substrate and enzyme in the reaction. This intermediate complex allows the ATP to transfer its third phosphate group, with its energy, to the substrate, a process called phosphorylation.

This is illustrated by the following generic reaction:. When the intermediate complex breaks apart, the energy is used to modify the substrate and convert it into a product of the reaction. The ADP molecule and a free phosphate ion are released into the medium and are available for recycling through cell metabolism. Figure 2. In phosphorylation reactions, the gamma phosphate of ATP is attached to a protein.