Asynchronous flight muscles in insects are able to achieve contractions in the range of 250-1000 Hz because
A)they have very fast Ca²⁺ ATPase pumps.
B)they have muscles that don't depend on Ca²⁺ regulation at all.
C)they have very high amounts of parvalbumin in the cytosol.
D)the TnC can rapidly change its affinity for Ca²⁺,leading to rapid contraction/relaxation cycles.

Question

Quizplus · Accepted Answer

Asynchronous insect flight muscles use a process called stretch activation, where they rely on rapid changes in the affinity of troponin C (TnC) for calcium ions to achieve rapid contractions. This allows for contractions in the high frequency range of 250-1000 Hz. Therefore, the best choice is D, which describes the rapid changes in affinity of TnC for calcium ions.

Asynchronous Flight Muscles in Insects Are Able to Achieve Contractions