Question

Which of the following statements describes a typical feature of protein import into mitochondria?

A. Proteins are imported in a fully folded state

B. Protein import is driven by ATP hydrolysis

C. Protein import involves a chaperone that keeps the protein unfolded in the cytosol

D. The entire process (from signal sequence recognition to signal peptide cleavage) does not require any energy

E. Protein depends on diffusion of proteins through porins, followed by active import into the mito matrix through an aqueous translocation channel

Answers B, C, and E all seem right but there has to be only one answer.

Answer 1

Here the correct option is E. Option A is not correct because proteins are imported in unfolded state into the mitochondria. Although option B, C and E are correct but option B and C are not the typical feature of protein import into mitochondria because many other protein transport require ATP for example transport of protein through cell membrane requires ATP (active transport). In the same way chaperons (posttranslational modifying proteins) are used in many protein transport.