400px|right|thumb|Simplified cross-section of a mitochondrion and a submitochondrial particle, showing the particle's inverted membrane orientation. Whereas whole submitochondrial particles can perform oxidative phosphorylation yielding ATP, destabilized particles lacking F<sub>1</sub> particles consume oxygen and oxidize NADH without synthesizing ATP, and free F<sub>1</sub> particles catalyze the hydrolysis of ATP into ADP.
A submitochondrial particle (SMP) is an artificial vesicle made from the inner mitochondrial membrane. They can be formed by subjecting isolated mitochondria to sonication, freezing and thawing, high pressure, or osmotic shock.