{"id":227935,"date":"2025-06-06T15:31:15","date_gmt":"2025-06-06T15:31:15","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=227935"},"modified":"2025-06-06T15:31:17","modified_gmt":"2025-06-06T15:31:17","slug":"which-of-the-following-is-carried-out-when-camp-functions-as-a-second-messenger-select-one-activates-all-cytosolic-protein-kinases-b","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/06\/06\/which-of-the-following-is-carried-out-when-camp-functions-as-a-second-messenger-select-one-activates-all-cytosolic-protein-kinases-b\/","title":{"rendered":"Which of the following is carried out when cAMP functions as a second messenger Select one Activates all cytosolic protein kinases b."},"content":{"rendered":"\n

Which of the following is carried out when cAMP functions as a second messenger Select one Activates all cytosolic protein kinases b. Activates the cAMP-dependent protein kinase Acts second in importance to AMP d Acts outside the cell to influence cellular processes<\/p>\n\n\n\n

The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n

Correct Answer:<\/strong> b. Activates the cAMP-dependent protein kinase<\/strong><\/p>\n\n\n\n

\n\n\n\n

Explanation<\/h3>\n\n\n\n

Cyclic AMP (cAMP) is a critical second messenger in many biological signaling pathways. It is synthesized from ATP by the enzyme adenylyl cyclase<\/strong>, which is activated by various first messengers<\/strong> such as hormones (e.g., adrenaline, glucagon) that bind to G-protein-coupled receptors<\/strong> (GPCRs) on the cell membrane.<\/p>\n\n\n\n

Once produced inside the cell, cAMP does not act outside the cell<\/strong>; rather, it functions within the cytoplasm<\/strong> to mediate cellular responses. Its primary role<\/strong> is to activate cAMP-dependent protein kinase<\/strong>, also known as Protein Kinase A (PKA)<\/strong>. This activation is crucial for the regulation of various physiological processes.<\/p>\n\n\n\n

When cAMP binds to the regulatory subunits of PKA, it causes a conformational change that releases the catalytic subunits. These free catalytic subunits then phosphorylate specific target proteins, leading to changes in enzyme activity, gene expression, and other cellular functions.<\/p>\n\n\n\n

For example:<\/p>\n\n\n\n

    \n
  • In liver cells, cAMP signaling can lead to the breakdown of glycogen<\/strong> into glucose.<\/li>\n\n\n\n
  • In cardiac muscle cells, it can increase heart rate<\/strong> and contractility<\/strong>.<\/li>\n\n\n\n
  • In neurons, it can affect neurotransmitter release<\/strong> and synaptic plasticity<\/strong>.<\/li>\n<\/ul>\n\n\n\n

    Let\u2019s also clarify why the other options are incorrect:<\/p>\n\n\n\n

      \n
    • a. Activates all cytosolic protein kinases<\/strong> \u2013 This is false because cAMP specifically activates PKA<\/strong>, not all kinases.<\/li>\n\n\n\n
    • c. Acts second in importance to AMP<\/strong> \u2013 Misleading. While AMP has roles in energy metabolism (e.g., activating AMP-activated protein kinase), cAMP is a distinct signaling molecule<\/strong> with its own specific pathway.<\/li>\n\n\n\n
    • d. Acts outside the cell to influence cellular processes<\/strong> \u2013 Incorrect. cAMP functions inside the cell<\/strong>, unlike some first messengers that operate extracellularly.<\/li>\n<\/ul>\n\n\n\n

      Thus, the correct answer is b. Activates the cAMP-dependent protein kinase<\/strong>, as this accurately describes the function of cAMP as a second messenger.<\/p>\n\n\n\n

      \"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

      Which of the following is carried out when cAMP functions as a second messenger Select one Activates all cytosolic protein kinases b. Activates the cAMP-dependent protein kinase Acts second in importance to AMP d Acts outside the cell to influence cellular processes The Correct Answer and Explanation is: Correct Answer: b. Activates the cAMP-dependent protein […]<\/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-227935","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/227935","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=227935"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/227935\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=227935"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=227935"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=227935"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}