Each myosin II molecule of the heavy chain can be digested into smaller constituents, one of which binds ATP. Which is that constituent?
A) light meromyosin
B) S1 subfragment
C) S2 subfragment
D) papain
E) trypsin

Question

Quizplus · Accepted Answer

The S1 subfragment is the portion of the myosin II molecule that binds ATP. This subfragment also contains the actin binding site and is responsible for the movement of myosin II along actin filaments. The S2 subfragment is responsible for the formation of the myosin II filament and does not bind to ATP. Light meromyosin is a larger constituent of the myosin II molecule and contains both the S1 and S2 subfragments. Papain and trypsin are proteases and are not constituents of the myosin II molecule.

Each Myosin II Molecule of the Heavy Chain Can Be