0
What else can I help you with?
What substances causes the myosin head to change shape?
ATP (adenosine triphosphate) is the main substance that causes the myosin head to change shape during muscle contraction. When ATP binds to the myosin head, it energizes the myosin molecule and allows it to detach from actin, resetting the myosin head for the next contraction cycle.
When ATP attaches to a myosin head, what specific role does it play in the process of muscle contraction?
When ATP attaches to a myosin head during muscle contraction, it provides the energy needed for the myosin head to detach from actin, allowing the muscle to relax and reset for the next contraction.
What happens to ATP when it binds to Myosin?
When ATP binds to myosin, it causes myosin to release actin, allowing for muscle relaxation. The energy stored in ATP is used to detach myosin from actin and prepare the cross-bridge for another contraction cycle.
What is needed to attach and detach myosin heads from actin?
For attachment of myosin heads to actin, calcium ions must bind to troponin, causing tropomyosin to move out of the way, exposing the binding site on actin. ATP then binds to the myosin head, leading to its activation and attachment to actin. For detachment, ATP is hydrolyzed, causing a conformational change in the myosin head that releases it from actin.
What is the source of energy on the myosin head?
The energy on the myosin head comes from ATP (adenosine triphosphate) molecules. When ATP is hydrolyzed, it releases energy that is used to power the movement of the myosin head during muscle contraction.
When does the myosin head cock back to store energy for the next cycle?
The myosin head cocks back to store energy for the next cycle during the cross-bridge cycling process in muscle contraction. This occurs after the powerstroke phase, where the myosin head binds to actin and pulls the thin filament towards the center of the sarcomere. The cocking of the myosin head allows it to reset and be ready for the next binding to actin during muscle contraction.
Where does ATP attach during muscle contraction?
During muscle contraction, ATP attaches to the myosin heads of the thick filaments in the muscle fibers. When ATP binds to myosin, it causes the myosin head to detach from the actin filament, allowing for a new cycle of cross-bridge formation and muscle contraction to occur. The hydrolysis of ATP then provides the energy necessary for the myosin head to pivot and pull the actin filament, leading to muscle shortening.
What provides the energy to break the connection between actin and myosin?
ATP, of course. When the myosin head extends towards the actin thin filament it has in it's active site ADP and P +. So, when the stroke is over the ADP and P+ fall out and are replaced by ATP, which immediately metabolizes to ADP and P +.
Does myosin have the ability to swivel when powered by ATP?
Yes...ATP causes myosin to detach from actin. Then, Hydrolysis of ATP, which results in ADP and P, causes conformational change in myosin head to swivel or pivot about its axis and then weakly bind to an actin filament. Once the myosin head binds, a conformational change in the myosin head will cause the P to leave (the ADP is still stuck on). The leaving of the P causes the power stroke or "the pulling of the actin filament/rowing stroke". ADP then leaves and the myosin is now back at its original state.
What makes rigormortis cease after 72 hours?
The myosin heads detach from actin, allowing the muscles to relax; prior to rigor mortis, Directly after death ATP is not produced therefore, Ca +2 is absent within the myosin binding sites on the actin, which leads to the myosin heads not being able to detach from actin, this condition doesnt allow the muscle to relax, aka rigor mortis. For the muscle to relax or for rigor mortis to cease the myosin heads detach from actin.
What acts as ATPase during the contraction cycle of muscle?
myosin cross-bridges
What converts the myosin head into the high-energy state?
The hydrolysis of ATP by myosin activates the myosin head and converts it into a high-energy state. This process releases energy that is used to power muscle contraction.
