Final answer:
The TOM complex is indeed essential for the transport of all nucleus-encoded proteins into mitochondria, which is a true statement. Proteins destined for the mitochondria contain a signal peptide and require chaperone proteins like HSP70 for proper folding and import.
Step-by-step explanation:
The statement that the TOM complex is required for the import of all nucleus-encoded mitochondrial proteins is True. The TOM complex facilitates the transfer of proteins from the cytosol into the mitochondria. Proteins that are synthesized in the cytoplasm and destined for the mitochondria present a signal peptide which directs them to the mitochondrial outer membrane. Upon reaching the outer membrane, they bind to the TOM complex, which includes receptor proteins that span the outer mitochondrial membrane (OM) and cristal membrane (CM). The receptor protein then delivers the protein to the inner mitochondrial membrane via membrane contact proteins that act as a channel for entry into the mitochondrial matrix. However, proteins cannot cross the membrane alone. They require HSP70 chaperone protein assistance to unfold the protein as it passes through the TOM complex and refold once inside the mitochondria for functional activity.