A mitochondria cannot produce new molecules. what structure is most likely not functioning properly?

The H + Pump

Explanation:

The proton pump is required for energy production by the Electron Transport Chain. The proton pump establishes a proton gradient across the mitochondrial membrane. This proton gradient runs the ATP producing enzyme, ATP synthase which in turn adds an inorganic phosphate (Pi) to ADP to produce ATP. If the proton pump malfunctions, no electrochemical gradient is established across the membrane. This inhibits the activation of the ATP synthase complex. Therefore, the primary function of the mitochondria i. e. energy production is not achieved.