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The sliding filament model of contraction involves actin filaments overlapping myosin filaments.
Annalise Quitzon
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Which myofilaments actually do the pulling during the sliding filament model of muscle contraction?
thick filaments
What is the model that best describes the contraction of the muscle called?
There are different models that describe the contraction of muscles. Not everyone agrees on which is best. A couple of the models are the sliding-filament model and Huxley's model.
How does a muscle contract according to the sliding-filament model of muscles contraction?
When skeletal (or cardiac) muscle contracts, the thin and thick filaments in each sarcomereslide along each other without their shortening, thickening, or folding.
Sliding filament model which proteinS have a calcium binding site?
The actin filaments have a Ca+2 binding site.
How does a muscle contact according to the sliding-filament model of muscle contraction?
When skeletal (or cardiac) muscle contracts, the thin and thick filaments in each sarcomereslide along each other without their shortening, thickening, or folding.
What is an explanation of how a muscle contracts?
The popular model of muscle contraction is "Sliding filament hypothesis" which is proposed by A.F.Huxely and H.E. Huxely. According to this hypothesis filaments of myofibrils (actin and myosin) slide over each other for the contraction. Muscle cells are not compressed or stretched. Calcium ions are released from sarcoplasmic reticulum causing re-orientation in actin filament. This enables it to bind to the myosin extensions (known as globular heads or cross bridges). The myosin filament binds and splits an ATP molecule. As the result the myosin head binds to the actin filament further ahead. The globular head moves (bends) and the actin filament attached to it also moves and overlaps the myosin filament. Because of this the actin and myosin filament occupy less space when their overlap is maximum. At this stage the sarcomere (containing unit of myofibrils) is contracted thus the muscle contraction occurs. As long as the sarcoplasmic reticulum provides the ATP and calsium ions, the myosin can crawl along the actin and muscle contractions continue. The enzyme ATPase breaks down ATP into ADP to provide energy for muscle contraction. The energy is stored in form of glycogen in muscles which is converted into glucose and then into ATP when muscles contract. During intensive muscle activity phosphocreatin is broken down into creatin and phosphate group. This phosphate group then combines with ADP to form ATP. animation will help you in understanding muscle contraction. see the related link below
What are the steps in sliding filament theory?
Before contraction:1) no nerve impulse to myoneural junction.2) Ca++ in the sarcoplasmic reticulum3) combining of actin and myosin is prevented by a tropomyosin-troponin complex that attatches to the actin.Contraction:1) an action potential (nerve impulse) travels along a neural axon to a myoneural junction (synapse)2) Acetylcholine (neurotransmitter) is released from the synaptic vesicles of the neuron.3) acetylcholine diffuses over into the sacrolemma and the t-tubules.4) Ca++mis released from the sarcoplasmic reticulum.5) the Ca++ then binds to the actin degrading the tropomyosin-troponin complex to expose myosin attatchment sights6) the heads of the myosin myofilaments attatch to the exposed attatchment sights on actin filament7) ATP binds to the heads of the myosin filaments. breakdown of the ATP to ADP+p releases energy and causes a bending of myosin heads.8) another ATP binds to the myosin head causing it to release the actin filament then attatch again with the head unbent. again the ATP breaks down and the process continues.To relax:1) nerve impulse stops2) active transport returns Ca++ to the sarcoplasmic reticulum3) ATP's are reformed (ADP+P+energy=ATP)4) Tropomyosin-troponin complex reforms causing the myosin to release the actin5) when the filaments release each other they slide back to the resting position.
What is the name of the theory muscle contraction illustrated in the transparency?
In short, the basic contraction unit of the muscle is the sarcomere. Many sarcomeres work serially and in parallel to acheive the full contraction ability of the muscle. The sarcomere is made up of many filaments of Actin and Myosin, two types of protein based filaments that reach out towards each other from opposing sides of the sarcomere. When the muscle is at rest, the Actin and myosin filaments overlap each other the least. In order for the muscle to contract, the filaments from the opposing sides slide over each other thus pulling both walls of the sarcomere towards each other, with them. When the muscle is fully contacted, the filaments overlap each other the most. The sliding motion is activated by calcium that floods the sarcomeres (at the end of a process that is triggered by a command from a motor nerve). The calcium reveals sites on the Actin filaments at which molecular 'whips' extending from the Myosin filaments, can throw themselves, attach, pull, and leave, using the muscle's energy reserves in the process. Each molecular whip works at its own time (much like cylinders in an internal combustion engine), so that in any given time, contact between the filaments is being made by some of the whips.
Describe the sliding filament model of muscle contraction?
The sliding filament model of muscle contraction explains how muscles produce force in order to contract. Two filaments, actin and myosin, slide over one another to shorten the entire length of the sarcomere, thus producing muscle contraction.
What is the sliding bar in a breech loading firearm?
what model firearms ???
What is the power source forsliding filament model of muscle movement?
Adenosine triphosphate. (ATP)
Will a sliding door for a 1988 vw transporter fit a 1982 model?
No.
