Proteins can also be delivered to organelles such as mitochondria. Delivery here involves several specialized proteins.

Mitochondria are organelles that produce large amounts of ATP, an energy molecule used in many cellular processes.

ATP is produced by a complex called ATP Synthase embedded in the mitochondrial membrane.

ATP Synthase uses a proton gradient to power ATP production. This gradient is maintained by the transfer of electrons through a chain of complexes called the Electron Transport System.