Question

Proteins encoded by nuclear genes and destined for the mitochondrial matrix are

Choose one:
A. able to diffuse into the mitochondrial intermembrane space first.
B. in possession of a signal sequence for targeting to the mitochondria.
C. transported across the membrane as a folded protein.
D. synthesized on ribosomes on the rough ER.

Answer 1

The proteins encoded by nuclear genes and destined for the mitochondrial matrix have a signal sequence for targeting to the mitochondria.

Step-by-step explanation:

The correct answer is B. Proteins encoded by nuclear genes and destined for the mitochondrial matrix are in possession of a signal sequence for targeting to the mitochondria.

Proteins synthesized in the cytosol and destined for the mitochondria have an N-terminal signal peptide that recognizes and binds to a receptor protein at the outer mitochondrial membrane. This signal peptide directs the protein to the appropriate destination and helps facilitate its transport across the membrane into the mitochondrial matrix.

Once inside the mitochondria, the protein is further processed, and the signal peptide is typically clipped off.