{"id":184450,"date":"2025-01-21T05:16:47","date_gmt":"2025-01-21T05:16:47","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=184450"},"modified":"2025-01-21T05:16:50","modified_gmt":"2025-01-21T05:16:50","slug":"repressible-and-inducible-operons-are-two-types-of-neg-structure-and-function-of-each-in-regards-to-gene-expression","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/01\/21\/repressible-and-inducible-operons-are-two-types-of-neg-structure-and-function-of-each-in-regards-to-gene-expression\/","title":{"rendered":"Repressible and inducible operons are two types of neg structure and function of each in regards to gene expression"},"content":{"rendered":"\n

Repressible and inducible operons are two types of neg structure and function of each in regards to gene expression. ative gene Regulation. 1. 2. Where does the polymerase bind? 3. In the presence of high levels of lactose and glucose, which of the two would be the primary source of energy for a prokaryote<\/p>\n\n\n\n

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

Repressible and inducible operons<\/strong> are two mechanisms of negative gene regulation<\/strong> in prokaryotic organisms, such as bacteria. Below is an explanation of their structure and function in relation to gene expression, as well as answers to the additional questions.<\/p>\n\n\n\n

\n\n\n\n

Repressible Operon<\/strong><\/h3>\n\n\n\n
    \n
  1. Structure and Function:<\/strong><\/li>\n<\/ol>\n\n\n\n
      \n
    • A repressible operon is typically “on” and actively transcribed unless a specific molecule, called a corepressor, is present to inhibit transcription.<\/li>\n\n\n\n
    • Example: The trp operon<\/em> (tryptophan operon). It encodes enzymes necessary for synthesizing tryptophan.<\/li>\n\n\n\n
    • In the presence of high tryptophan levels, tryptophan binds to the repressor protein, activating it. The active repressor binds to the operator region, blocking RNA polymerase and shutting down transcription.<\/li>\n<\/ul>\n\n\n\n
        \n
      1. Where does the polymerase bind?<\/strong><\/li>\n<\/ol>\n\n\n\n
          \n
        • The RNA polymerase binds to the promoter region<\/strong>, upstream of the operon. However, if the repressor is bound to the operator, transcription is blocked.<\/li>\n<\/ul>\n\n\n\n
          \n\n\n\n

          Inducible Operon<\/strong><\/h3>\n\n\n\n
            \n
          1. Structure and Function:<\/strong><\/li>\n<\/ol>\n\n\n\n
              \n
            • An inducible operon is typically “off” and only transcribed when an inducer molecule inactivates the repressor protein.<\/li>\n\n\n\n
            • Example: The lac operon<\/em> (lactose operon). It encodes enzymes for lactose metabolism.<\/li>\n\n\n\n
            • In the absence of lactose, the repressor binds to the operator, preventing transcription. When lactose (inducer) is present, it binds to the repressor, causing its detachment from the operator. This allows transcription to proceed.<\/li>\n<\/ul>\n\n\n\n
                \n
              1. Where does the polymerase bind?<\/strong><\/li>\n<\/ol>\n\n\n\n
                  \n
                • The RNA polymerase binds to the promoter region<\/strong>. If the repressor is removed, transcription proceeds.<\/li>\n<\/ul>\n\n\n\n
                  \n\n\n\n

                  Energy Source in Presence of High Lactose and Glucose<\/strong><\/h3>\n\n\n\n

                  In the presence of high lactose and glucose, prokaryotes preferentially use glucose as their primary energy source. This preference is due to catabolite repression<\/strong>: glucose suppresses the activation of the lac operon<\/em> by inhibiting cAMP production. Without cAMP, the CRP (catabolite activator protein) cannot bind to the promoter, reducing the efficiency of RNA polymerase binding and transcription of the lac operon<\/em>. Thus, lactose is metabolized only after glucose is depleted.<\/p>\n","protected":false},"excerpt":{"rendered":"

                  Repressible and inducible operons are two types of neg structure and function of each in regards to gene expression. ative gene Regulation. 1. 2. Where does the polymerase bind? 3. In the presence of high levels of lactose and glucose, which of the two would be the primary source of energy for a prokaryote The […]<\/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-184450","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/184450","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=184450"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/184450\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=184450"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=184450"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=184450"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}