During the crossbridge cycle in a skeletal muscle, the next step after a myosin head binds...

During the crossbridge cycle in a skeletal muscle, the next step after a myosin head binds to actin is that the myosin head
a. changes conformation in the power stroke.
b. unbinds from the actin.
c. binds to calcium.
d. contributes to rigor mortis.

Expert Solution

Answer : “a” changes confirmation in the power stroke.

Explanation: In resting stage of the muscle tropomycin covers the active site of actin, this prevents the cross bridge formation between myosin and actin.

Binding of ATP to the myosin changes the angle of myosin head and it is ready to bind to the actin site.In this state myosin is at high energy level(the ATP is hydrolysed to ADP and inorganic phosphate)

The contraction of muscles is initiated by binding of calcium ions to troponin leading to the exposure(troponin removes tropomycin from the active site) of active site of actin, the myosin head fills the gap,inorganic phosphate is released and myosin forms a cross bridge with actin. As soon as myosin binds actin it loses energy and there is a conformational change in myosin.since myosin spends the energy, it moves through the power stroke and pulls actin filament toward the M line leading to shortening of sarcomere and the muscle contracts.

gladiator answered 5 months ago

Skeletal Muscle System Muscle Contraction The phase of the sliding filament mechanisms are activation of myosin...

Skeletal Muscle System Muscle Contraction The phase of the sliding filament mechanisms are activation of myosin followed by __________; the last step is _______. The detachment phase requires ___________. The power stroke phase requires __________. A crossbridge is formed between _________. Calcium binds to ________ which is necessary for _________. At the neuromuscular junction, __________ is released by the neuron; it binds to ________ on the muscle cell to eventually trigger ___________. Action potentials in skeletal muscle cells are needed...

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

During the excitation phase of the skeletal muscle cell contraction, the following occurs: 1) the muscle...

During the excitation phase of the skeletal muscle cell contraction, the following occurs: 1) the muscle fiber develops tension and shortens 2) the muscle fiber relaxes and returns to its original length 3) nerve action potentials lead to muscle action potentials A growing long bone in a child has only two types of cartilage at the epiphysis. These two areas are 1) elastic cartilage and epiphyseal plate 2) epiphyseal plate and epiphyseal line 3) primary and secondary ossification centers 4)...

How does Calcium in the cytosol influence muscle contraction? Describe the ATPase cycle of myosin II.

During static muscle activity, there is a strong compressive effect from skeletal muscle contraction coupled with...

During static muscle activity, there is a strong compressive effect from skeletal muscle contraction coupled with an absence of rhythmic muscle activity. Describe how this would change arterial pressure (afterload) and venous return (preload) compared with dynamic activity.

Calcium plays a role during contraction of both skeletal and cardiac muscle, but there are important...

Calcium plays a role during contraction of both skeletal and cardiac muscle, but there are important differences in the mechanisms leading to increased calcium concentration and contraction between both muscle types. Could you explain them?

Question 1. which if the following does not occur during the "Excitation" of a skeletal muscle?...

Question 1. which if the following does not occur during the "Excitation" of a skeletal muscle? A. The myosin head binding site on actin is exposed B. ATPase on myosin heads split ATP C. The passive force of contraction increases D. The cell membrane depolarizes Question 2. Which if the following does not occur during skeletal muscle contraction? A. titin fibers compress B. Actin and myosin shorten C. sacromeres shorten Question 3. Which of the following describes the relationship between...

As skeletal muscle temperature increases during exercise, what happens to the activity rate of the enzymes...

As skeletal muscle temperature increases during exercise, what happens to the activity rate of the enzymes involved in ATP resynthesis?

You are obviously still breathing during an anaerobic activity like sprinting. If the skeletal muscle cells...

You are obviously still breathing during an anaerobic activity like sprinting. If the skeletal muscle cells in your legs are performing lactic acid fermentation to produce the necessary ATP for their proper functioning, what is happening to the O2 gas you are breathing?

Which off the following does NOT occur during skeletal muscle contraction? Titin fibers compress Actin and...

Which off the following does NOT occur during skeletal muscle contraction? Titin fibers compress Actin and myosin shorten Sarcomers shorten 2. Action potential propagated along the sarcolemma stimulate ___________ located on transverse tubules.2. Nicotinic receptors Ryanodine receptors DHP receptors 3. Which of the following does not occur during the "Excitation" of a skeletal muscle? Group of answer choices The cell membrane depolarizes ATPase on myosin heads split ATP The myosin head binding site on actin is exposed The passive force...

Question