Tiêu đề 22. GENE STRUCTURE.pdf ✅

PHARMD GURU Page 1 1) INTRODUCTION TO GENES AND GENOMIC ORGANIZATION: Genes are the fundamental units of heredity, carrying the instructions required for protein and RNA synthesis. Genomic organization refers to the arrangement of genes and non-coding regions within the complete set of an organism’s DNA, known as the genome. KEY FEATURES OF GENOME ORGANIZATION:  Prokaryotic Genome: Genes are arranged in continuous stretches without introns and are often grouped into operons for coordinated expression.  Eukaryotic Genome: Genes are interrupted by introns and contain regulatory sequences like enhancers and silencers, allowing complex gene regulation. Understanding genome structure helps in studying gene expression, replication, and cellular functions. 2)GENE STRUCTURE: A. ORGANIZATION OF GENES: A gene is a segment of DNA that encodes a specific protein or functional RNA. It consists of both coding (exons) and non-coding (introns and regulatory regions). Figure 1: Hierarchical Organization of Chromatin Structure THE GENE: GENOME STRUCTURE AND FUNCTION

PHARMD GURU Page 3 D. CONCEPT OF OPERONS IN PROKARYOTES:  Definition: An operon is a cluster of genes controlled by a single promoter and operator sequence.  Example: Lac Operon (E. coli)  Regulates lactose metabolism.  The lac repressor binds to the operator and prevents transcription in the absence of lactose.  When lactose is present, it binds to the repressor, allowing gene expression.  Significance: Ensures efficient gene regulation based on environmental needs. Figure 3: Diagram illustrating prokaryotic and eukaryotic gene structures Figure 4: Flow of genetic information from DNA to RNA to protein, illustrating