Question

Which subset of the following is directly involved in driving protein import into the mitochondrial matrix space? Choose all correct sources. Your answer would be a string composed of letters A to G only, in alphabetical order, e.g. AE.

A. ATP hydrolysis inside mitochondria
B. ATP hydrolysis outside mitochondria
C. GTP hydrolysis inside mitochondria
D. GTP hydrolysis outside mitochondria
E. Light
F. Membrane potential across the inner membrane
G. Membrane potential across the outer membrane

Answer 1

ATP hydrolysis inside mitochondria and the membrane potential across the inner mitochondrial membrane are the subsets directly involved in driving protein import into the mitochondria, with the latter being generated by the electrochemical gradient of hydrogen ions formed during electron transport chain activities.

Step-by-step explanation:

The subsets directly involved in driving protein import into the mitochondrial matrix space are ATP hydrolysis inside mitochondria (A) and the membrane potential across the inner membrane (F). During protein import, proteins enter the mitochondria with the help of specific translocases located in both the outer and inner mitochondrial membranes. The energy required for this process primarily comes from the hydrolysis of ATP within the mitochondria and the electrochemical gradient, or membrane potential, across the inner membrane. This membrane potential is generated by the movement of hydrogen ions across the inner membrane during the electron transport chain activities, which is part of oxidative phosphorylation. The gradient drives the import of proteins through voltage-dependent gating of the translocase in the inner membrane. Therefore, the correct answers from the options provided would be A and F.