Treatment of isolated sperm axonemes with 0.6 M NaCl has been shown to remove selectively the outer arms from the A microtubules of the axoneme,leaving the inner arms in place.What would be the most likely effect on the NaCl-treated axoneme when ATP was added to the medium?
A)The axoneme would fall apart completely.
B)The axonemes would beat at about half the rate of the intact axoneme.
C)The central microtubules would disassemble leaving the rest of the axoneme intact.
D)The axoneme would be solubilized.
E)Every element of the axoneme would be permanently cross-linked.

Question

Quizplus · Accepted Answer

The outer arms of the A microtubules are responsible for generating the power stroke during flagellar or ciliary movement. Their removal leaves behind the inner arms and the central microtubules, which do not participate in movement. Addition of ATP to the medium would cause the inner arms to move, but at a reduced rate compared to the intact axoneme, as the power stroke generated by the outer arms is missing. Therefore, choice B is the most likely effect on the NaCl-treated axoneme when ATP is added to the medium.

Treatment of Isolated Sperm Axonemes with 0