Decide whether each of these statements is true or false, andthen explain why.
A. Like the lumen of the ER, the interior of the nucleus istopologically equivalent to the outside of the cell.
B. Membrane bound and free ribosomes, which are structurally andfunctionally identical, differ only in the proteins they happen tobe making at a particular time.
C. To avoid the inevitable congestion that would occur iftwo-way traffic through a single pore were allowed, nuclear porecomplexes are specialized so that some mediate import while othersmediate export.
D. The TOM complex is required for the import of allnucleus-encoded mitochondrial proteins.
E. There is no fundamental distinction between signalingmolecules that bind to cell surface receptors and those that bindto intracellular receptors.
F. All small intracellular mediators (second messengers) arewater soluble and diffuse freely through the cytosol.
Decide whether each of these statements is true or false, andthen explain why.
A. Like the lumen of the ER, the interior of the nucleus istopologically equivalent to the outside of the cell.
B. Membrane bound and free ribosomes, which are structurally andfunctionally identical, differ only in the proteins they happen tobe making at a particular time.
C. To avoid the inevitable congestion that would occur iftwo-way traffic through a single pore were allowed, nuclear porecomplexes are specialized so that some mediate import while othersmediate export.
D. The TOM complex is required for the import of allnucleus-encoded mitochondrial proteins.
E. There is no fundamental distinction between signalingmolecules that bind to cell surface receptors and those that bindto intracellular receptors.
F. All small intracellular mediators (second messengers) arewater soluble and diffuse freely through the cytosol.
