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What is the protein filament that slides inward toward the middle of a sarcomere during a muscle contraction?
Wiki User
∙ 12y ago
Actin
Wiki User
∙ 12y ago
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Which region of a sarcomere shortens during contraction?
During a contraction, the I bands and H zone of a sarcomere contract. The A bands remain unchanged.
What change occur in sacomere during muscle contraction?
The sarcomere itself will become shorter.The sarcomere will shorten.
What happens when thin filaments in a muscles fiber slide over the thick filament?
Contraction or relaxation of muscle fibre, due to similar effect in sarcomere
What happens to a muscle contraction if there is an excess amount of either Ca2 plus or ATP present during the contraction?
During muscle contraction the actin heads pull the sarcomere closed
Which region of the sarcomere shortens during contraction the dark band the light band or both?
Dark
Describe which bands and zones of a sarcomere stay the same and which narrow or disappear during muscle contraction?
M line
Physical evidence that supports the sliding filament theory of muscle contraction includes?
decreased width of the H band during contraction
Which myofilaments actually do the pulling during the sliding filament model of muscle contraction?
thick filaments
In addition to myosin what other protein is involved in skeletal muscle contraction?
Myosin acts with Actin during muscle contraction
What causes muscle contraction?
Muscle contraction in initiated by an action potential sent from the brain or spinal cord to the axon terminal of a motor neuron. Calcium then goes into the axon terminal which causes the release of the neurotransmitter acetylcholine which binds to receptors on the plasmalemma. Calcium then diffuses into the sarcoplasm and binds to troponin. The troponin is then shifted to expose binding sites on the actin filament allowing for the linkage of actin and myosin. The the actin filaments are then pulled inward during shortening the sarcomere and resulting in muscular contraction :) I learnt this stuff in year 9
What chemical reactions occur in the muscle during latent period of muscle contraction?
During the latent period of muscle contraction Ca++ is being released from the sacroplasmic reticulum and filament movement is taking up slack. This takes approx. 2 milliseconds.
Do the you band and H zones become narrower during contraction?
Yes the H band shortens. During contraction the length of the sarcomere or from z line to z line must decrease in length. Thus the I band which is bisected by the z line must shorten as well as the H band, even though the H band is bisected by the A band it must shorten to allow fior this decrease in length. The A band does not shorten because it is composed of the entire length of myosin whose length never decreases during contraction.
