Chapter 9: Biotechnology : Principles and Processes

Biology • Class 12

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Chapter Analysis

Advanced13 pages • English

Quick Summary

This chapter introduces the principles and processes of biotechnology, focusing on genetic engineering and bioprocess engineering. It covers the tools of recombinant DNA technology, including restriction enzymes, ligases, and cloning vectors, and explains processes like isolation of DNA, gene cloning, and gene transfer. The chapter details how recombinant DNA technology enables large-scale production of biotechnological products using bioreactors.

Key Topics

  • Principles of Biotechnology
  • Tools of Recombinant DNA Technology
  • Processes of Recombinant DNA Technology
  • Restriction Enzymes
  • Cloning Vectors
  • Polymerase Chain Reaction (PCR)
  • Bioreactors
  • Downstream Processing

Learning Objectives

  • Understand the principles and processes of biotechnology.
  • Explain the tools used in recombinant DNA technology.
  • Describe the sequence of steps in gene cloning and transfer.
  • Identify the types and roles of restriction enzymes in DNA manipulation.
  • Recognize the applications of bioreactors in large-scale biotechnological processes.
  • Discuss the ethical implications of genetic engineering.

Questions in Chapter

Can you list 10 recombinant proteins which are used in medical practice?

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Make a chart showing a restriction enzyme, the substrate DNA on which it acts, the site at which it cuts DNA, and the product it produces.

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From what you have learnt, can you tell whether enzymes are bigger or DNA is bigger in molecular size? How did you know?

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What would be the molar concentration of human DNA in a human cell?

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Do eukaryotic cells have restriction endonucleases? Justify your answer.

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Besides better aeration and mixing properties, what other advantages do stirred tank bioreactors have over shake flasks?

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Collect 5 examples of palindromic DNA sequences.

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Can you recall meiosis and indicate at what stage a recombinant DNA is made?

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How can a reporter enzyme be used to monitor transformation of host cells by foreign DNA in addition to a selectable marker?

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Additional Practice Questions

Explain the role of restriction enzymes in recombinant DNA technology.

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Answer: Restriction enzymes act as molecular scissors that cut DNA at specific sequences known as recognition sites, facilitating the creation and cloning of recombinant DNA molecules.

What are the advantages of using a plasmid as a cloning vector?

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Answer: Plasmids are advantageous as cloning vectors because they can replicate independently, are easy to manipulate, and allow for the insertion of foreign DNA. They also often contain selectable markers for identifying successful incorporations.

Describe how PCR is used to amplify DNA.

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Answer: PCR or Polymerase Chain Reaction amplifies DNA by using cycles of denaturation, annealing of primers, and extension to exponentially replicate a specific DNA segment in vitro.

What is the significance of 'sticky ends' generated by restriction enzymes?

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Answer: Sticky ends are overhanging sequences created by restriction enzymes that enable the binding of complementary DNA fragments, thus facilitating the ligation process to form recombinant DNA.

What is the purpose of a bioreactor in biotechnological processes?

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Answer: Bioreactors are used to provide optimal conditions for the cultivation of microorganisms or cells under sterile conditions, enabling large-scale production of biotechnological products like proteins, enzymes, and vaccines.

Explain the concept of 'downstream processing' in biotechnology.

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Answer: Downstream processing refers to the separation, purification, and formulation of bioproducts post-biosynthesis to prepare them for market use, involving techniques like centrifugation, filtration, and chromatography.

Outline the steps involved in the transformation of a host cell with recombinant DNA.

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Answer: Transformation involves making the host cell 'competent' to take up DNA, introducing recombinant DNA into the cell, and then selecting cells that have successfully integrated the foreign DNA using selectable markers.

Differentiate between exonucleases and endonucleases.

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Answer: Exonucleases remove nucleotides from the ends of DNA molecules, while endonucleases cleave DNA at specific internal sites within the molecule.

How can gene cloning be used to study gene function?

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Answer: Gene cloning allows for the amplification and isolation of a gene of interest, which can then be expressed in a host organism to study its function, interaction, and role in biological processes.

What ethical considerations arise from the use of genetic engineering and biotechnology?

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Answer: Ethical considerations include the potential for creating genetically modified organisms that may impact biodiversity, issues of patenting bioproducts, and concerns regarding the manipulation of genetic material.