Question

sliding filament model

1. the thick and thin filaments past each other during contraction.
2. calcium binds to which protein, allowing myosin to attach?

a) actin b) tropomyosin c) troponin d) myosin

1. the myosin head binds to actin to form a.
2. atp provides energy for myosin to:

a) pull on actin b) detach and reset c) shorten actin d) produce calcium

Explanation:

• Question 12: In the sliding filament model, during muscle contraction, the thick (myosin) and thin (actin) filaments slide past each other.
• Question 13: Calcium binds to troponin. When calcium binds to troponin, it causes a conformational change that moves tropomyosin away from the myosin - binding sites on actin, allowing myosin to attach.
• Question 14: The myosin head binds to actin to form a cross - bridge. This is a key step in the power stroke of muscle contraction.
• Question 15: ATP provides energy for myosin to detach and reset. After the power stroke (pulling on actin), the myosin head needs to detach from actin. Hydrolysis of ATP provides the energy for this detachment and for the myosin head to reset to its original position for another cycle of contraction.

Answer:

1. slide
2. c) Troponin
3. cross - bridge
4. b) Detach and reset