FoFl complex

The actual site in the mitochondrion where ATP is made is Complex V (also called ATP synthase or the FOFl complex). It is located on the inner mitochondrial cristae and has the structure shown in Figure 15.14. 

Complex V (also called ATP synthase or the FOFl complex) is a multi-protein structure with three-fold symmetry, resembling a mushroom (Figure 15.14). It consists of a top knob called FI and a stalk, which joins the knob to the base called FO in the inner mitochondrial membrane. The FI knob projects into the mitochondrial matrix and contains three dimers arranged like segments of an orange around the stalk. The stalk contains T and proteins 5 is attached to protein b of the FO base, which also contains proteins a and c plus others. The 01/ 760 abc complex is called a stator. 

See also Uncoupling ETS and Oxidative Phosphorylation, The FOFl Complex, Integrity of... 

The CFO-CFl complex is the ATP synthase complex of the chloroplast that functions similarly to the FOFl complex of mitochondria. It is located in the thylakoid membranes, as shown in Figure 17.15. During photosynthesis, electrons are pumped into the thylakoid lumen from the stroma, forming a proton gradient. Movement of the protons out of the thylakoid lumen through the CFO-CFl complex back to the stroma provides the driving force for photophosphorylation, the process of making ATP in photosynthesis. A similar mechanism is responsible for ATP synthesis in oxidative phosphorylation. 

ATP is generated in the thylakoid membranes of chloroplasts by a complex called CFO-CFl and is very similar to the FOFl complex of mitochondria. As in mitochondria, passage of protons through the ATP synthase complex (CFO-CFl), is the driving force (and energy source) for ATP synthesis. 

See also The FOFl Complex (from Chapter 15), Photosystem II, Photosystem I, Cyclic Electron Flow, Thylakoid Lumen, Cytochrome b6f, Plastoquinones,... 

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