Muscle Physiology: Myosin Mechanism

The video tutorial explains the mechanism of myosin ATPase, focusing on its role in muscle contraction. It covers the binding of ATP to myosin, leading to crossbridge detachment from actin. The hydrolysis of ATP activates the myosin head, allowing it to reattach to actin and perform a power stroke, resulting in sarcomere contraction. The process involves the formation and dissociation of metaphosphate and orthophosphate, ultimately leading to the release of ADP and the completion of the cycle.

What is the primary focus of the video tutorial?

• Anatomy and Physiology

• Environmental Science

• Biochemistry and Organic Chemistry

• Physics and Mathematics

What happens when ATP binds to myosin in the initial step?

• Crossbridge formation

• Crossbridge detachment

• ATP hydrolysis

• Muscle contraction

What is released during ATP hydrolysis that helps move myosin into the activated position?

• Adenosine monophosphate

• Carbon dioxide

• Water molecule

• Free energy

What unusual species is formed after ATP hydrolysis?

• Phosphoric acid

• Pyrophosphate

• Metaphosphate

• Orthophosphate

What strengthens the myosin-actin interaction during the cycle?

• Phosphate release

• ADP attachment

• Water molecule addition

• ATP binding

What is the result of the power stroke in the myosin ATPase cycle?

• Thin filament moves toward the M line

• Muscle relaxation

• Crossbridge detachment

• ATP synthesis

What completes the myosin ATPase cycle?

• Crossbridge detachment

• ADP binding

• Myosin head deactivation

• Phosphate attachment