atp is needed in muscle contraction for what process? course hero

What is the relationship between ATP and muscle contraction?

What is the relationship between muscle contraction and ATP? Short answer: ATP provides the energy for cooperating myosin and actin filaments (in muscle cell sarcomeres) to do the actual work required for muscle contraction. Myofibrils contain the myofilaments mainly responsible for the contraction of the muscle fiber, myosin and actin.

What are the three roles of ATP in muscle contraction?

Three functions of ATP in muscle contraction are the following: (1) Its hydrolysis by an ATPase activates the myosin head so it can bind to actin and rotate; (2) Its binding to myosin causes detachment from actin after the power stroke; and (3) It powers the pumps that transport calcium ions from the cytosol back into.

What produces the most ATP for muscle contraction?

Muscle Metabolism

• Within the muscle fiber. ATP available within the muscle fiber can maintain muscle contraction for several seconds.
• Creatine phosphate. Creatine phosphate, a high‐energy molecule stored in muscle cells, transfers its high‐energy phosphate group to ADP to form ATP. ...
• Glucose stored within the cell. ...
• Glucose and fatty acids obtained from the bloodstream. ...

How is ATP replaced in muscles?

The entire reaction that turns ATP into energy is a bit complicated, but here is a good summary:

• Chemically, ATP is an adenine nucleotide bound to three phosphates.
• There is a lot of energy stored in the bond between the second and third phosphate groups that can be used to fuel chemical reactions.
• When a cell needs energy, it breaks this bond to form adenosine diphosphate (ADP) and a free phosphate molecule.

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What is ATP needed for in muscle contraction?

ATP is critical for muscle contractions because it breaks the myosin-actin cross-bridge, freeing the myosin for the next contraction.

How is ATP used in muscle contraction quizlet?

ATP energy is used to detach the myosin head from it's binding site on the actin filament during muscle contraction.

Is ATP required for muscle contraction and relaxation?

ATP is required for both muscle contraction and muscle relaxation.

How is ATP hydrolysis involved in muscle contraction?

Myosin binds to actin at a binding site on the globular actin protein. Myosin has another binding site for ATP at which enzymatic activity hydrolyzes ATP to ADP, releasing an inorganic phosphate molecule and energy. ATP binding causes myosin to release actin, allowing actin and myosin to detach from each other.

What is the role of ATP in muscle function quizlet?

What is the role of ATP in muscle function? ATP provides energy that enables myosin to form cross-bridges with actin. ATP enables myosin to detach from actin.

What is the function of ATP in muscle relaxation?

ATP binding to myosin during the contractile cycle results in myosin detachment from actin, and energy liberated from subsequent ATP hydrolysis is then used to drive the next contractile cycle. ATP is also used to lower myoplasmic calcium levels during muscle relaxation.

How many ATP are required for the contraction cycle?

Answer: One cycle of a single myosin ATPase head expends 1 molecule of ATP, but it takes thousands of these myosin heads, each producing about 5 power stroke per second (1 ATP/stroke), to produce a noticeable or useful contraction of the whole muscle.

What is required for a muscle to contract?

A Muscle Contraction Is Triggered When an Action Potential Travels Along the Nerves to the Muscles. Muscle contraction begins when the nervous system generates a signal. The signal, an impulse called an action potential, travels through a type of nerve cell called a motor neuron.

When a muscle cell requires energy to perform its work of contraction what happens to ATP?

When a muscle cell demands energy to perform its work of contraction, what happens to ATP? ATP is broken down.

What happens to myosin after binding to ATP?

After this happens, the newly bound ATP is converted to ADP and inorganic phosphate, P i.

What is the mechanism of muscle shortening?

The motion of muscle shortening occurs as myosin heads bind to actin and pull the actin inwards. This action requires energy, which is provided by ATP. Myosin binds to actin at a binding site on the globular actin protein. Myosin has another binding site for ATP at which enzymatic activity hydrolyzes ATP to ADP, releasing an inorganic phosphate molecule and energy.

What happens to myosin after a power stroke?

After the power stroke, ADP is released; however, the cross-bridge formed is still in place, and actin and myosin are bound together. ATP can then attach to myosin, ...

What happens when the actin is pulled?

As the actin is pulled, the filaments move approximately 10 nm toward the M line. This movement is called the power stroke, as it is the step at which force is produced. As the actin is pulled toward the M line, the sarcomere shortens and the muscle contracts. When the myosin head is “cocked,” it contains energy and is in a high-energy ...

What is the enzyme that is responsible for the binding of myosin?

The enzyme at the binding site on myosin is called ATPase. The energy released during ATP hydrolysis changes the angle of the myosin head into a “cocked” position. The myosin head is then in a position for further movement, possessing potential energy, but ADP and P i are still attached.