Molecular Basis of Inheritance 08 | Human Genome Project, Lac Operon | Class 12th/CUET

NCERT Wallah2 minutes read

Operons and gene regulation are discussed in Lecture 7, with specific focus on the Human Genome Project and the regulation of gene expression in prokaryotes through the operon model. The process of transcription, translation, and protein synthesis, as well as the role of regulatory genes, operators, and promoters in operons, are key points in understanding gene expression regulation.

Insights

  • The operon model, developed by Jacob and Monod, explains how genes are regulated in prokaryotes through coordinated groups of genes that work together in metabolic pathways.
  • The Human Genome Project, a significant undertaking requiring substantial funding and manpower, aimed to sequence 3.3 * 10^9 base pairs, showcasing the complexity and scale of genetic research in understanding human inheritance.

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Recent questions

  • What is the operon concept?

    The operon concept refers to coordinated groups of genes that function together in a metabolic pathway, regulating gene expression in cells.

  • Why do eukaryotes require more gene expression regulation?

    Eukaryotes require more gene expression regulation due to the complexity of their cellular structure, necessitating precise control over gene activity.

  • Who developed the operon model?

    The operon model was developed by geneticist Jacob and biochemist Monod, specifically for prokaryotes to explain gene expression regulation.

  • How does lactose presence affect gene expression?

    Lactose presence triggers enzyme production in the inducible system, allowing RNA polymerase access to genes for transcription and subsequent protein synthesis.

  • What is the main goal of the Human Genome Project?

    The main goal of the Human Genome Project, initiated in 1990, was to sequence 3.3 * 10^9 base pairs to understand human genetic makeup, requiring extensive manpower and bioinformatics for data analysis.

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Summary

00:00

Operons and Gene Expression Regulation in Genetics

  • Lecture number seven for D se Chapter Basis of Inheritance focuses on the concept of operons and gene expression regulation.
  • The Human Genome Project is highlighted as a significant project involving substantial funding.
  • The operon concept is introduced to explain how gene expression is regulated within cells.
  • The process of gene transcription from DNA to RNA, translation to protein, and enzyme formation is discussed.
  • Eukaryotes require more gene expression regulation due to the complexity of their cellular structure.
  • The operon model, developed by geneticist Jacob and biochemist Monod, is specific to prokaryotes.
  • Operons are defined as coordinated groups of genes that function together in a metabolic pathway.
  • Structural genes, operators, promoters, and regulator genes work together in operons to regulate gene expression.
  • Constitutive genes are always expressed, while luxury genes are expressed only when needed.
  • Regulator genes control the activity of operator genes, acting as activators or repressors to regulate gene expression.

20:58

Lactose Induced Enzyme Production in Cells

  • Lactose presence in the medium requires enzymes for lactose breakdown and entry into cells.
  • Genes expression depends on lactose presence for enzyme production.
  • Regulatory gene I is constitutive, always expressing itself.
  • Repression protein blocks RNA polymerase from transcribing genes.
  • Repression protein inactivates when lactose is present, allowing RNA polymerase access to genes.
  • Small amounts of lactose are crucial for switching on the operon.
  • Inducer lactose triggers enzyme production in the inducible system.
  • Negative control regulates lactose presence for operon activation.
  • Repression protein prevents RNA polymerase from transcribing genes, leading to operon switch-off.
  • Specific lock-and-key model ensures enzyme production when lactose is present.

38:28

Protein Synthesis and Human Genome Project

  • RNA polymer rotates to form messenger RNA (mRNA) in the nucleus.
  • mRNA undergoes modification in the nucleus, with introns removed and exons added.
  • Proteins are synthesized in the cytoplasm, requiring mRNA to exit the nucleus.
  • Ribosomes attach to mRNA, moving along to carry amino acids for protein synthesis.
  • Amino acids are placed in a specific order based on codons on mRNA.
  • Peptide bonds form between amino acids, creating proteins until the process halts.
  • The Human Genome Project began in 1990, aiming to complete by 2003.
  • The project involved sequencing 3.3 * 10^9 base pairs, requiring extensive manpower and bioinformatics for data storage and analysis.
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