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What occurs when actin and myosin filaments slide over each other?
Wiki User
∙ 6y ago
The power stroke of the cross bridge which binds ATP disconnecting it from the actin.
Wiki User
∙ 12y ago
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What is the dark staining area of a sarcomere?
It is a section of the Sarcomere that stretches from one end of the Myosin filament to the other, and also includes parts of the Actin filaments that overlaps it.
If a researcher was interested in slowing down the movement of amoebas by disrupting their cell membranes which protein filaments should she be studying?
Considering that Amoeba sp., among other animal cells, possesses the capacity of dynamic surface extensions containing actin filaments. These filaments produce pseudopodia-stubby distensions of the actin cortex-with which they walked over surfaces. Therefore if there is an interest in slowing down the movement we would have to be interested in fibroblast cells that regularly extend a thin, sheetlike process known as lamellipodium, which contains a dense meshwork of actin filaments. Moreover, actin filaments can form the so-called microspikes, which are about 0.1 um wide and 5 to 10 um long and contain a loose bundle of about 20 actin filaments oriented with their plus ends pointing outward. In conclusion, it will be a good idea to look at the actin protein in order to make a research in amoeba's locomotion processes.
What are the three types of microfilaments?
(1)Microfilaments (also know as actin filaments) are actually only one type of filament in the eukaryotic cytoskeleton. The two other filaments are (2)intermediate filaments and (3)microtubules.
What is composed of actin?
Actin is essentially a ball ('globular') with two key features: 1. a particular region binds and hydrolyzes adenosine triphosphate (ATP); 2. Other regions allow actin molecules to bind to one another head-to-tail. I won't discuss the ATP hydrolysis here. When actin molecules bind each other, they form a spiral-staircase-like ('alpha-helical') string called a 'filament.' Multiple actin filaments come together to form bundles or fibers. These higher-order structures are so big and so prevalent that they can be seen in living cells through a microscope. The atomic structure of globular actin is available for free here: http://www.ncbi.nlm.nih.gov/Structure/mmdb/mmdbsrv.cgi?uid=47984
What two things are needed for cells to get energy?
Lots of things are needed for the muscle cell to work. For contraction to take place, actin and myosin interact with each other, Sodium and Potassium ions are exchanged across the cell membrane, and calcium is also required.
The sliding filament mechanism of muscle contraction involves?
during contraction, the thin filaments slide past the thick filaments so that actin and myosin filaments overlap.
What happens to a sarcomere when muscle length changes?
1. Arrangement of thick and thin filaments: In each sarcomere two sets of actin filaments extend partway toward the center. The myosin filaments are arranged such that they partially overlap the actin filaments. Myosin heads on each side point away from the center of the sarcomere.2. During contraction, the interaction of myosin heads with the actin filaments pulls the thin filaments toward the center of the sarcomere. The actin and myosin filaments slide past each other.3. Cross-bridges = attachement betwn myosin heads and binding sites on actin filaments.4. When a muscle cell is stimulated, myosin heads are energized by ATP. They attach to adjacent actin filaments, and tilt in a short "power stroke" toward the center of the sarcomere. Each power sroke requires an ATP. With many power strokes in rapid succession, the actin filaments are made to slide past the myosin filaments.
Where do myosin cross bridges attach during muscle contraction?
Myosin functions as an ATPase utilizing ATP to produce a molecular conformational change of part of the myosin and produces movement. Movement of the filaments over each other happens when the globular heads protruding from myosin filaments attach and interact with actin filaments to form crossbridges. The myosin heads tilt and drag along the actin filament a small distance (10-12 nm). The heads then release the actin filament and adopt their original conformation.
What myofibril contains only thick myofilaments?
No, myofibrils contain both thick filaments (myosin) and thin filaments (actin) which when activated overlap each other as part of muscular contraction.
What other protein is involved in skeletal muscle contraction?
Myosin and actin
What are the two contractile proteins of muscle?
The two types of protein that are in your muscle cells are actin and myosin. What they do is they slide past each other and that makes a muscle cell work.
What is the dark staining area of a sarcomere?
It is a section of the Sarcomere that stretches from one end of the Myosin filament to the other, and also includes parts of the Actin filaments that overlaps it.
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 prevents actin myofilaments from sliding backward when a myosin head releases?
During contraction, there are always some myosin heads attached to the actin myofilament when other myosin heads are detaching.
What does a muscle cell do that no other cells can do?
Only muscle cell contracts...(filaments contain actin and myosin) that helps them to contract
Which step allows actin and myosin to release from each other?
an ATP molecule attaches to myosin apex answers
In addition to myosin what other protein is involved in skeletal muscle contraction?
Myosin acts with Actin during muscle contraction
