{"id":154872,"date":"2024-10-15T14:35:00","date_gmt":"2024-10-15T14:35:00","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=154872"},"modified":"2024-10-15T14:35:04","modified_gmt":"2024-10-15T14:35:04","slug":"rank-the-sequence-of-cross-bridge-cycling-starting-with-the-myosin-binding-sites-being-exposed-and-ending-with-relaxation-due-to-cross-bridge-cycling-ending","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2024\/10\/15\/rank-the-sequence-of-cross-bridge-cycling-starting-with-the-myosin-binding-sites-being-exposed-and-ending-with-relaxation-due-to-cross-bridge-cycling-ending\/","title":{"rendered":"Rank the sequence of cross bridge cycling, starting with the myosin-binding sites being exposed and ending with relaxation due to cross bridge cycling ending."},"content":{"rendered":"\n<p>&#8220;Rank the sequence of cross bridge cycling, starting with the myosin-binding sites being exposed and ending with relaxation due to cross bridge cycling ending. Do not overlap any events.&#8221;<br>Sequence:<\/p>\n\n\n\n<p>a. Calcium ions pumped into the sarcoplasmic reticulum<br>b. Myosin head forms cross bridge with actin<br>c. Myosin binding sites covered<br>d. Power stroke moves thin filament<br>e. Cross bridges detach from actin<br>f. Myosin head is re-energized<br>g. Calcium ion concentration decreases below the threshold for binding to troponin<br>h. ATP attaches to myosin head<\/p>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-6-color\">The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p>To correctly rank the sequence of cross-bridge cycling in muscle contraction, starting from the exposure of myosin-binding sites and ending with relaxation, we can use the following order:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>b. Myosin head forms cross bridge with actin<\/strong><\/li>\n\n\n\n<li><strong>d. Power stroke moves thin filament<\/strong><\/li>\n\n\n\n<li><strong>e. Cross bridges detach from actin<\/strong><\/li>\n\n\n\n<li><strong>h. ATP attaches to myosin head<\/strong><\/li>\n\n\n\n<li><strong>f. Myosin head is re-energized<\/strong><\/li>\n\n\n\n<li><strong>g. Calcium ion concentration decreases below the threshold for binding to troponin<\/strong><\/li>\n\n\n\n<li><strong>a. Calcium ions pumped into the sarcoplasmic reticulum<\/strong><\/li>\n\n\n\n<li><strong>c. Myosin binding sites covered<\/strong><\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation:<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Myosin Head Forms Cross Bridge with Actin (b)<\/strong>: The process begins when calcium ions bind to troponin, causing a conformational change that moves tropomyosin away from the myosin-binding sites on actin. This exposes the binding sites, allowing the energized myosin heads to form cross-bridges with actin.<\/li>\n\n\n\n<li><strong>Power Stroke Moves Thin Filament (d)<\/strong>: Once the cross-bridge is formed, the myosin head pivots and pulls the actin filament toward the center of the sarcomere in a movement called the power stroke. This results in muscle contraction.<\/li>\n\n\n\n<li><strong>Cross Bridges Detach from Actin (e)<\/strong>: After the power stroke, the myosin heads release from the actin. This detachment is crucial for the cycling process to continue.<\/li>\n\n\n\n<li><strong>ATP Attaches to Myosin Head (h)<\/strong>: The binding of ATP to the myosin head is essential for the release of the cross-bridge from actin. ATP must be present for the myosin head to detach and reset.<\/li>\n\n\n\n<li><strong>Myosin Head is Re-energized (f)<\/strong>: Once ATP is hydrolyzed into ADP and inorganic phosphate, the myosin head is re-energized and primed for another cycle.<\/li>\n\n\n\n<li><strong>Calcium Ion Concentration Decreases Below the Threshold for Binding to Troponin (g)<\/strong>: When the stimulation ceases, calcium ions are actively transported back into the sarcoplasmic reticulum, decreasing their concentration in the cytoplasm. This leads to the re-covering of the binding sites.<\/li>\n\n\n\n<li><strong>Calcium Ions Pumped into the Sarcoplasmic Reticulum (a)<\/strong>: The active transport of calcium ions into the sarcoplasmic reticulum signifies the end of muscle contraction.<\/li>\n\n\n\n<li><strong>Myosin Binding Sites Covered (c)<\/strong>: Finally, as calcium ions are removed, tropomyosin moves back to cover the myosin-binding sites, preventing further cross-bridge formation and leading to muscle relaxation.<\/li>\n<\/ol>\n\n\n\n<p>This sequence illustrates the dynamic process of muscle contraction and relaxation through cross-bridge cycling, highlighting the importance of ATP and calcium ions in muscle function.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&#8220;Rank the sequence of cross bridge cycling, starting with the myosin-binding sites being exposed and ending with relaxation due to cross bridge cycling ending. Do not overlap any events.&#8221;Sequence: a. Calcium ions pumped into the sarcoplasmic reticulumb. Myosin head forms cross bridge with actinc. Myosin binding sites coveredd. Power stroke moves thin filamente. Cross bridges [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-154872","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/154872","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=154872"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/154872\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=154872"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=154872"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=154872"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}