Which of the following statements regarding the structure of contractile proteins are correct? I. Each actin filament is made up of two 'F' actins, which are wound helically around each other. II. Two types of troponins are distributed at regular intervals on the tropomyosin. III. The globular head of meromyosin has binding sites for ATP and troponins. IV. Myosin is a structural protein that also has enzymatic activity.

Question

Which of the following statements regarding the structure of contractile proteins are correct? I. Each actin filament is made up of two 'F' actins, which are wound helically around each other. II. Two types of troponins are distributed at regular intervals on the tropomyosin. III. The globular head of meromyosin has binding sites for ATP and troponins. IV. Myosin is a structural protein that also has enzymatic activity. (A) II, III and IV (B) I and IV (C) I, II and III (D) II and IV

Tardigrade Admin · Accepted Answer

Three types of protein troponin: troponin T, troponin I and troponin C are distributed at regular intervals on the tropomyosin. The globular head of meromyosin is an active ATPase enzyme. It has binding sites for ATP and active sites for 'actin'. Due to its ATPase activity, mysosin which is a contractile structural protein also has enzymatic action.