Steps of Cross Bridge Cycle Flashcards

Steps of the Cross Bridge Cycle

• Cross bridge formation occurs when a phosphorylated myosin head binds to an actin myofilament, initiating muscle contraction.

The Power Stroke

• During the power stroke, ADP and inorganic phosphate (Pi) are released from the myosin head.
• The myosin head undergoes a conformational change to a bent, low-energy state.
• This shape change generates a pulling force that moves the actin filament toward the M line, facilitating muscle contraction.

Cross Bridge Detachment

• ATP binds to the myosin head, resulting in the breakdown of the cross bridge, which allows actin and myosin to separate.

Cocking of the Myosin Head

• The attached ADP is hydrolyzed by myosin ATPase into ADP and Pi.
• This hydrolysis event converts the myosin head back into a high-energy state, preparing it for another cycle of contraction.

Explore the critical stages of the cross bridge cycle with these flashcards. Each card details a specific step, from cross bridge formation to power stroke and detachment. Perfect for students looking to master muscle contraction mechanisms!