試題詳解

38. About actin cytoskeleton, which of the following descriptions are correct?
(A) At steady state of actin polymer formation, the concentration of monomeric actins is determined by the critical concentration Cc.
(B) The rate-limiting step in actin polymerization is the elongation phase from a short actin oligomer to a long polymer.
(C) ATP-G-actins add at both the (+) and the (-) ends, but adding of ATP-G-actins is faster at the (-) end.
(D) Arp2/3 prevents actin polymers from growth, whereas capping proteins promote actin branching.
(E) The small GTPases Rho, Rac and Cdc42 are critical regulators of actin dynamics. 39-40. Jared is studying how cell division is controlled, using the Xenopus (a kind of frog) fertilized oocytes