Question

The import of proteins into mitochondria requires energy in the form of ATP for their [____] and of mitochondria that are energized, with an electrochemical gradient. The imported proteins must be synthesized on [____] ribosomes as they are bound to requisite [____]. Protein import itself requires that the protein have an N-terminal targeting sequence that folds into an [____] for interaction with the import receptor on the outer mitochondrial membrane. The translocase of the outer membrane (TOM) complex consists of seven proteins, and they have overlapping specificities, but gene deletion studies show that only two of them are [____].

(1) protein synthesis; membrane-bound; receptors; amphiphilic α-helix; necessary

(2) unfolding; soluble; membrane receptors; targeting sequence; functional

(3) folding by chaperones; cytosolic; membrane receptors; import targeting sequence; essential

(4) movement into the matrix; membrane-bound; signal sequences; amphipathic α-helix; required

(5) interactions with chaperones; soluble; chaperones; amphipathic α-helix; essential

Answer 1

The correct option is (4) Movement into the matrix; Membrane bound; signal sequences; amphipathic alpha-helix; required.