Biotechnology (Principles and Processes) – NEET Notes

✅ Table of Contents

  1. Introduction to Biotechnology
  2. Principles of Biotechnology
  • Genetic Engineering
  • Chemical Engineering (Bioprocess Engineering)
  1. Tools of Genetic Engineering
  • Restriction Enzymes (Molecular Scissors)
  • Cloning Vectors
  • DNA Ligase
  • Competent Host (Transformation)
  1. Techniques in Genetic Engineering
  • Recombinant DNA Technology (rDNA Technology)
  • Polymerase Chain Reaction (PCR)
  • Gel Electrophoresis
  • Blotting Techniques (Southern, Northern, Western)
  1. Biotechnology Applications
  • Agricultural Applications
  • Medical Applications
  • Industrial Applications
  • Environmental Applications
  1. Biotechnology and Its Implications
  • Ethical Issues
  • Risks and Benefits
  1. Biotechnology in NCERT: Key Terms and Definitions
  2. Conclusion

✅ 1. Introduction to Biotechnology

Biotechnology is a multidisciplinary field that utilizes biological systems, living organisms, or their derivatives to develop products and technologies. It integrates concepts from biology, chemistry, and engineering to develop useful applications.

Historical Background

  • 1919: Term “biotechnology” coined by Karl Ereky.
  • 1973: First recombinant DNA molecule created by Herbert Boyer and Stanley Cohen.
  • 1982: First genetically engineered product (insulin) approved by FDA.
  • 1990: Human Genome Project initiated.
  • 2003: Human Genome Project completed.

Branches of Biotechnology

  • Red Biotechnology: Medical applications (e.g., vaccines, gene therapy).
  • Green Biotechnology: Agricultural applications (e.g., GM crops).
  • White Biotechnology: Industrial applications (e.g., enzyme production).
  • Blue Biotechnology: Marine and aquatic applications (e.g., aquaculture).

✅ 2. Principles of Biotechnology

(i) Genetic Engineering

Genetic engineering involves modifying an organism’s genetic material by inserting, deleting, or altering specific DNA sequences. The basic steps include:

  1. Isolation of DNA: Extracting the desired DNA from the donor organism.
  2. Cutting DNA using Restriction Enzymes: Using molecular scissors to cut DNA at specific sites.
  3. Insertion of DNA into a Vector: The target DNA is inserted into a vector (e.g., plasmid) to form recombinant DNA.
  4. Transformation into Host: The recombinant DNA is introduced into a host cell (e.g., E. coli).
  5. Selection and Screening: Identifying and selecting genetically transformed cells.
  6. Cloning and Expression: The recombinant DNA multiplies and expresses the desired gene.

(ii) Bioprocess Engineering

Bioprocess engineering uses living cells or their components to produce commercial products:

  • Upstream Processing: Involves preparation of the culture (e.g., inoculation, fermentation).
  • Downstream Processing: Includes purification and recovery of the final product.

✅ 3. Tools of Genetic Engineering

(i) Restriction Enzymes (Molecular Scissors)

Restriction enzymes are endonucleases that cut DNA at specific recognition sites. They were first discovered in 1963 in Escherichia coli.

  • Types of Restriction Enzymes:
  • Type I: Cut at random sites far from the recognition site.
  • Type II: Cut at specific recognition sites. (Most commonly used in genetic engineering)
  • Type III: Cut DNA at short distances from the recognition site.
  • Examples:
  • EcoRI → Recognizes GAATTC and cuts between G and A.
  • HindIII → Recognizes AAGCTT and cuts between A and A.

(ii) Cloning Vectors

Vectors are DNA molecules used to carry foreign DNA into host cells. Ideal vectors should have:

  • Origin of Replication (ori): Allows autonomous replication.
  • Selectable Marker: Helps identify recombinant cells.
  • Multiple Cloning Site (MCS): Contains sites for restriction enzymes.
  • Promoter and Terminator Sequences: For gene expression.

Examples of Cloning Vectors:

  • Plasmids: Circular, extrachromosomal DNA used in bacterial transformation.
  • Bacteriophages: Viruses that infect bacteria.
  • Cosmids: Hybrid vectors with features of plasmids and phages.
  • Artificial Chromosomes: e.g., YAC (Yeast Artificial Chromosome), BAC (Bacterial Artificial Chromosome).

(iii) DNA Ligase

  • It joins two DNA fragments by forming phosphodiester bonds.
  • Used in ligation of foreign DNA into vectors.

(iv) Competent Host (Transformation)

Competent host cells are prepared to take up foreign DNA through:

  • Chemical Treatment: Using CaCl₂ to make bacterial cells porous.
  • Electroporation: Applying electric current to create temporary pores.
  • Microinjection: Injecting DNA directly into the nucleus.
  • Biolistics (Gene Gun): Shooting DNA-coated particles into plant cells.

✅ 4. Techniques in Genetic Engineering

(i) Recombinant DNA Technology (rDNA Technology)

Recombinant DNA technology allows cloning and expression of foreign genes in a host organism.

Steps in rDNA Technology

  1. Isolation of DNA
  2. Cutting DNA with Restriction Enzymes
  3. Inserting DNA into a Vector
  4. Transformation into Host Cells
  5. Selection of Transformed Cells
  6. Gene Cloning and Expression

(ii) Polymerase Chain Reaction (PCR)

PCR is used to amplify specific DNA sequences exponentially.
Steps in PCR:

  • Denaturation: Heating at 94-98°C to separate DNA strands.
  • Annealing: Cooling to 50-65°C for primer binding.
  • Extension: DNA polymerase synthesizes new strands at 72°C.

(iii) Gel Electrophoresis

Gel electrophoresis is used to separate DNA fragments based on size:

  • DNA is loaded into agarose gel.
  • An electric field is applied, and DNA migrates towards the positive electrode.
  • Ethidium bromide is used to stain DNA.

(iv) Blotting Techniques

  • Southern Blotting: For DNA analysis.
  • Northern Blotting: For RNA analysis.
  • Western Blotting: For protein analysis.

✅ 5. Applications of Biotechnology

(i) Agricultural Applications

  • Genetically Modified Crops (GMOs): Crops with improved traits (e.g., Bt cotton resistant to bollworm).
  • Transgenic Crops: Crops with foreign genes for pest resistance.
  • Biofertilizers and Biopesticides: Microbial fertilizers enhance soil fertility.

(ii) Medical Applications

  • Gene Therapy: Treating genetic disorders by replacing defective genes.
  • Recombinant Insulin: Produced by inserting human insulin gene into E. coli.
  • Vaccines: Recombinant DNA technology for vaccines (e.g., Hepatitis B vaccine).
  • Stem Cell Therapy: Using stem cells to regenerate damaged tissues.

(iii) Industrial Applications

  • Enzyme Production: Industrial enzymes (e.g., protease, lipase) for food processing.
  • Fermentation Technology: Producing antibiotics, alcohol, and organic acids.

(iv) Environmental Applications

  • Bioremediation: Using microbes to clean pollutants.
  • Biofuels: Genetically engineered organisms for ethanol production.

✅ 6. Biotechnology and Its Implications

Ethical Issues

  • GMO Controversy: Concerns over genetically modified food safety.
  • Gene Patenting: Ownership of genetic information.
  • Cloning Ethics: Moral concerns over human cloning.

Risks and Benefits

  • Benefits: Improved agriculture, better medicines, and sustainable solutions.
  • Risks: Ecological imbalance, unknown side effects, and ethical dilemmas.

✅ 7. Biotechnology in NCERT: Key Terms and Definitions

  • Plasmid: Circular DNA used as a vector.
  • Transgenic Organisms: Organisms containing foreign genes.
  • Bioreactors: Vessels used for large-scale fermentation.
  • ELISA: Enzyme-linked immunosorbent assay for disease diagnosis.
  • Cry Genes: Bacillus thuringiensis (Bt) genes used in GM crops.

✅ 8. Conclusion

Biotechnology has revolutionized medicine, agriculture, and industry. Its applications in healthcare, environment, and food production continue to grow. Understanding genetic engineering principles and techniques is vital for NEET aspirants, as it is a key topic in the biology syllabus.

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