Chapter 28, Problem 10E

Summary Introduction

To explain: The probable genetic defect that abolishes the sensitivity of the lac operon to the absence of glucose when other metabolic operons continue to be sensitive to the absence of glucose.

Introduction: In E. coli, an operon consists of the genes in a cluster, and it is transcribed from a promoter. There are mechanisms that control gene expression at different levels based on the binding of RNA polymerase at promoter region and the presence of repressors or activators. E. coli uses glucose as its source of energy and when it is less in amount, then it uses lactose. If glucose is less, the lac operon is controlled by cAMP receptor protein (CRP). It increases the gene expression and is positive gene regulation.