Biotechnology – Comprehensive Study Notes for B.Pharm Admission
Target Exam – IIT‑JEE / Competitive Entrance
Subject – Biology
Topic – Biotechnology
Author – Expert Teacher
Date – 2026‑10‑21
1. Introduction
Biotechnology is the application of life‑science principles (molecular biology, genetics, microbiology, biochemistry, and bioinformatics) to develop useful products and technologies. In the pharmaceutical domain, it underpins the design, production, and quality control of therapeutic proteins, vaccines, and gene‑based medicines.
2. Core Definitions
| Term | Definition |
|---|---|
| Biotechnology | The use of biological systems, living organisms, or derivatives to create or modify products or processes for a specific use. |
| Genetic Engineering | Direct manipulation of an organism’s genes using biotechnology. |
| Recombinant DNA (rDNA) | DNA molecules formed by joining fragments from two or more genomes. |
| Vector | A DNA molecule that can carry foreign DNA into a host cell and replicate. |
| Plasmid | A small, circular, double‑stranded DNA molecule that replicates autonomously in bacteria. |
| Restriction Enzyme | A protein that cleaves DNA at or near specific short sequences (restriction sites). |
| PCR (Polymerase Chain Reaction) | An enzymatic amplification method that produces millions of copies of a specific DNA fragment. |
| CRISPR‑Cas9 | A genome‑editing system derived from bacterial adaptive immunity. |
3. Historical Milestones
| Year | Milestone | Significance |
|---|---|---|
| 1970 | Discovery of restriction enzymes (Pauling & Streisinger) | First tool for cutting DNA |
| 1973 | First recombinant DNA (Sambrook, et al.) | Birth of genetic engineering |
| 1980 | First genetically modified animal (transgenic mouse) | Proof of concept for animal biotech |
| 1985 | First recombinant protein drug (Humulin) | First biotech drug on the market |
| 1996 | First monoclonal antibody (Rituximab) | Revolutionized therapeutic antibodies |
| 2002 | CRISPR‑Cas9 adapted for genome editing | Precise, efficient gene editing |
| 2018 | First gene‑edited babies (CRISPR) | Ethical debate, regulatory implications |
4. Basic Principles (Central Dogma & Beyond)
-
Central Dogma
DNA → RNA → Protein- Transcription: RNA polymerase synthesizes mRNA from DNA template.
- Translation: Ribosomes translate mRNA codons into amino acid chains.
-
Regulatory Elements
- Promoters: DNA sequences where RNA polymerase binds.
- Enhancers / Silencers: Modulate transcription levels.
- Terminator: Signals end of transcription.
-
Gene Expression Control
- Transcriptional (promoter strength, copy number).
- Post‑transcriptional (mRNA stability, splicing).
- Translational (ribosome binding site, codon usage).
- Post‑translational (protein folding, PTMs).
5. Genetic Engineering Workflow
| Step | Process | Key Points |
|---|---|---|
| 1. DNA Isolation | Extract plasmid or genomic DNA from donor organism. | Use of alkaline lysis, phenol‑chloroform, or column‑based kits. |
| 2. Restriction Digestion | Cut DNA with one or more restriction enzymes. | Recognise 4–8 bp palindromic sequences; sticky vs blunt ends. |
| 3. Ligation | DNA fragments ligated using DNA ligase (T4). | Requires compatible ends; ATP‑dependent. |
| 4. Transformation / Transduction / Conjugation | Introduce recombinant plasmid into host cells. | Heat shock, electroporation, or phage infection. |
| 5. Selection & Screening | Identify successful transformants. | Antibiotic resistance genes |