Question

In: Anatomy and Physiology

Which step of muscle contraction requires the presence of ATP?

Which step of muscle contraction requires the presence of ATP?

Solutions

Expert Solution

The muscle contraction cycle is triggered by calcium ions binding to the protein complex troponin, exposing the active-binding sites on the actin. As soon as the actin-binding sites are uncovered, the high-energy myosin head bridges the gap, forming a cross-bridge. Once myosin binds to the actin, the Pi is released, and the myosin undergoes a conformational change to a lower energy state. As myosin expends the energy, it moves through the "power stroke," pulling the actin filament toward the M-line. When the actin is pulled approximately 10 nm toward the M-line, the sarcomere shortens and the muscle contracts. At the end of the power stroke, the myosin is in a low-energy position.After the power stroke, ADP is released, but the cross-bridge formed is still in place. ATP then binds to myosin, moving the myosin to its high-energy state, releasing the myosin head from the actin active site. ATP can then attach to myosin, which allows the cross-bridge cycle to start again; further muscle contraction can occur. Therefore, without ATP, muscles would remain in their contracted state, rather than their relaxed state.


Related Solutions

ATP is required for both muscle contraction and muscle relaxation. Explain how ATP is used for...
ATP is required for both muscle contraction and muscle relaxation. Explain how ATP is used for contraction and how ATP is used for relaxation.
role of calcium role atp importance of hydrolysis of atp in muscle contraction
role of calcium role atp importance of hydrolysis of atp in muscle contraction
what is the role of atp in muscle contraction and the significance of stiffness in someone...
what is the role of atp in muscle contraction and the significance of stiffness in someone that is deceased?
The chemical process called _____ produces ___ ATP and supplies energy for muscle contraction for _____....
The chemical process called _____ produces ___ ATP and supplies energy for muscle contraction for _____. a. Creatine phosphate, 4, 15 seconds b. Kreb's cycle (aerobic respiration), 36, hours c. Glycolysis, 2, 30-60 seconds d. Creatine phosphate, 1, 15 seconds e. All of the above except A
You are investigating the effects of ATP, Ca2+, and other ions on skeletal muscle contraction, and...
You are investigating the effects of ATP, Ca2+, and other ions on skeletal muscle contraction, and are conducting two experiments. First using glycerinated muscle, you can compare the ability of muscle to contract under 3 experimental conditions (1: ATP; 2: KCl+MgCl2; and 3: ATP+KCl+MgCl2). Second, using fresh muscle, you compare the ability of muscle to contract under another 3 experimental conditions (1: ATP; 2: Ca2+; and 3: ATP+Ca2+). For each experiment, what results would you expect regarding the amounts of...
Discuss the specific role of ATP in muscle contraction. and give me the good conclusion of...
Discuss the specific role of ATP in muscle contraction. and give me the good conclusion of that
During the crossbridge cycle of skeletal muscle contraction, the binding of adenosine triphosphate (ATP) to the...
During the crossbridge cycle of skeletal muscle contraction, the binding of adenosine triphosphate (ATP) to the globular myosin head first causes which of the following? Select one: a. Movement of tropomyosin to expose the myosin binding site on the actin molecule b. Myosin head to bind to actin c. Myosin head to detach from actin d. Myosin head to swing forward pulling actin toward the M-line e. Myosin head to be cocked into its high-energy state
Question 2 Enzymes basically work by... A. Directly providing ATP for muscle contraction B. Lowering the...
Question 2 Enzymes basically work by... A. Directly providing ATP for muscle contraction B. Lowering the activation energy required to drive the reaction C. Combining with NAD+ to provide energy D. Helping oxygen attach to substrate during metabolism E. Both A and B Anaerobic glycolysis yields a net gain of... 5 ATP 10 ATP 8 ATP 2 ATP After a few minutes of easy jogging at a submaximal intensity, my oxygen consumption and heart rate reach a plateau and stay...
As the resistance (load) to muscle contraction increased, what happened to the velocity of muscle contraction?...
As the resistance (load) to muscle contraction increased, what happened to the velocity of muscle contraction? a) it increased b) it stays the same c) it increased dramatically and then leveled off d) it decreased 2) how is wave summation achieved in vivo (that is, in the living muscle)? a) by decreasing the amount of potassium b) by increasing the strength of a neuron’s action potential c) by increasing the frequency of neuron firing d) by myelinated great the neuron
Physiology -Discuss the three metabolic pathways that supply ATP for muscle contraction -Explain how navigational abilities...
Physiology -Discuss the three metabolic pathways that supply ATP for muscle contraction -Explain how navigational abilities promote reproductive success. Provide an example.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT