ATP GENETRATION / ATP SYNTHASE

ATP synthase  is an important enzyme that provides energy for the cell to use through the synthesis of adenosine triphosphate (ATP). ATP is the most commonly used "energy currency" of cells from most organisms. It is formed from adenosine diphosphate (ADP) and inorganic phosphate (Pi), and needs energy.

The overall reaction sequence is: ADP + Pi → ATP, where ADP and Pi are joined together by ATP synthase

Energy is often released in the form of hydrogen ions (H+

), moving down an electrochemical gradient, such as from the lumen into the stroma of chloroplasts or from the inter-membrane space into the matrix in mitochondria

Structure

Located within the thylakoid membrane and inner mitochondrial membrane, ATP synthase consists of 2 regions

the FO portion is within the membrane.

The F1 portion of the ATP synthase is above the membrane, inside the matrix of the mitochondria.

Mitochondria structure: (1) inner membrane, (2) outer membrane, (3) cristae, (4) matrix

The nomenclature of the enzyme has a long history. The F1 fraction derives its name from the term "Fraction 1" and FO (written as a subscript letter "o", not "zero") derives its name from being the oligomycin binding fraction.[1] Oligomycin, an antibiotic, is able to inhibit the FO unit of ATP synthase.

These functional regions consist of different protein subunits — refer to tables.

F1-ATP Synthase structure

The F1 particle is large and can be seen in the transmission electron microscope by negative staining.[2] These are particles of 9 nm diameter that pepper the inner mitochondrial membrane. They were originally called elementary particles and were thought to contain the entire respiratory apparatus of the mitochondrion, but, through a long series of experiments, Ephraim Racker and his colleagues (who first isolated the F1 particle in 1961) were able to show that this particle is correlated with ATPase activity in uncoupled mitochondria and with the ATPase activity in submitochondrial particles created by exposing mitochondria to ultrasound. This ATPase activity was further associated with the creation of ATP by a long series of experiments in many laboratories.