Question 10 Which of the following is NOT a true statement about cytoskeletal motor proteins? A. Cytoskeletal motor proteins utilize only cytoskeletal polymers that have intrinsic polarity. B. An actin-based motor protein is necessary for the movement of the bacterium Listeria within the cytoplasm of epithelial cells. c. proteins couple cycles of protein conformational change to cycles of nucleotide binding, hydrolysis and Motor release. D. Motor proteins have one or more globular head domains plus a tail domain that binds cargo. E. All cytoskeletal motor proteins are ATPases. Question 11 Which of the following statements applies to all three major classes of cytoskeletal polymers actin filaments and intermediate filaments)? A. they have intrinsic polarity B. they assemble from protein subunits synthesized on free polyribosomes C. they add subunits only at their ends D. they are involved in cell motility E. their constituent proteins are tissue specific Question 12 Which of the following is not a correct statement about the cytoskeleton? A. All forms of cell motility involve both motor proteins and changes in the assemblyldisassembly state of a cytoskeletal polymer. can not participate in cell motility. B. Intermediate filaments do not possess intrinsic polarity and hence C. Tubulin is a GTPase enzyme. tissues. D. Intermediate filaments are composed of different proteins in different E. Actin filaments and microtubules can add and remove subunits at both ends.