{"id":210190,"date":"2025-04-30T06:22:24","date_gmt":"2025-04-30T06:22:24","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=210190"},"modified":"2025-04-30T06:22:27","modified_gmt":"2025-04-30T06:22:27","slug":"the-specificity-of-an-antibody-is-due-to","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/04\/30\/the-specificity-of-an-antibody-is-due-to\/","title":{"rendered":"The specificity of an antibody is due to"},"content":{"rendered":"\n<p>The specificity of an antibody is due to<\/p>\n\n\n\n<p>a. its valence<br>b. The heavy chains<br>c. The Fc portion of the molecule<br>d. The variable portion of the heavy and light chain<\/p>\n\n\n\n<p><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-6-color\"><strong>The correct answer and explanation is :<\/strong><\/mark><\/p>\n\n\n\n<p>The correct answer is <strong>d. The variable portion of the heavy and light chains<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation:<\/h3>\n\n\n\n<p>The specificity of an antibody is determined by the unique structure of its antigen-binding sites. Antibodies are glycoproteins produced by plasma cells in response to an antigen. Each antibody consists of four polypeptide chains: two identical heavy chains and two identical light chains, connected by disulfide bonds. These chains form a Y-shaped structure with two distinct regions: the <strong>Fab<\/strong> (Fragment antigen-binding) region and the <strong>Fc<\/strong> (Fragment crystallizable) region.<\/p>\n\n\n\n<p>The <strong>variable region<\/strong> is the key to the antibody\u2019s specificity. This region is located at the tips of the arms of the Y-shaped antibody and is formed by parts of both the heavy and light chains. The variability in the amino acid sequence in this region allows the antibody to recognize and bind to a specific epitope (a unique molecular structure) on an antigen. The variability arises from the process of <strong>V(D)J recombination<\/strong>, a mechanism during immune cell development that shuffles gene segments, generating a diverse repertoire of antibodies capable of recognizing nearly any foreign substance.<\/p>\n\n\n\n<p>Each antibody has a unique antigen-binding site because of the specific arrangement of the variable regions of the heavy and light chains. These sites are highly complementary to the shape of the antigen&#8217;s epitope, allowing for a highly specific interaction between the antibody and antigen.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Why the other options are incorrect:<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>a. Its valence<\/strong>: While the valence (number of antigen-binding sites) of an antibody influences its ability to cross-link antigens, it does not determine the specificity. Antibodies can have a valence of 2 (for IgG) or more, but specificity is determined by the structure of the binding site, not the number of binding sites.<\/li>\n\n\n\n<li><strong>b. The heavy chains<\/strong>: The heavy chains contribute to the structure and class of the antibody (e.g., IgG, IgA, IgM), but the specificity of the antibody comes from the variable regions, not solely the heavy chains.<\/li>\n\n\n\n<li><strong>c. The Fc portion of the molecule<\/strong>: The Fc region is involved in immune system interactions, such as binding to receptors on immune cells (like macrophages or T cells). It plays a role in the effector functions of the antibody, such as opsonization or complement activation, but does not contribute to antigen specificity.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>The specificity of an antibody is due to a. its valenceb. The heavy chainsc. The Fc portion of the moleculed. The variable portion of the heavy and light chain The correct answer and explanation is : The correct answer is d. The variable portion of the heavy and light chains. Explanation: The specificity of an [&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-210190","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/210190","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=210190"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/210190\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=210190"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=210190"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=210190"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}