Biochemistry In what form do proteins cross the mitochondrial membranes? A Bound to an impoin protein a signal sequence B In fully folded form C In unfolded extended form attached to Hsp 70 chaperones D In unfolded extended form without chaperones 💡 Explanation In what form do proteins cross the mitochondrial membranes? ✓ Correct Answer: D. In unfolded extended form without chaperones