🧫 Biotechnology & Genetic Engineering: One Night Revision & Cram Sheet
Explain how a defined change in DNA is made, carried, expressed, and checked, and how that change is put to work in a fermenter, a protein, a pathway, a crop, an animal, or a medicine, under a safety and ethics framework that treats hazard and exposure as things to be judged rather than assumed away.
🌟 Core Axioms & High-Yield Golden Rules
7 Core PrinciplesNon-negotiable foundational truths frequently tested in direct conceptual and numerical exam questions. Click checkbox to mark as mastered.
Type II restriction endonucleases recognize palindromic sequences (4-8 bp), cleave within or adjacent to the recognition site without ATP, and generate 5'-overhangs, 3'-overhangs, or blunt ends.
💡 Type II = Palindromic cleavage, No ATPCloning vectors insert capacities: Plasmid (up to 10 kb), Bacteriophage lambda (10-20 kb), Cosmid (30-45 kb), BAC (100-300 kb), YAC (100-1000 kb / 1 Mb).
💡 Plasmid < Phage < Cosmid < BAC < YACPCR steps: Denaturation (94-98°C, splits dsDNA), Annealing (50-65°C, primer hybridization, ~5°C below Tm), Extension (72°C, Taq DNA polymerase synthesizes 5'->3'). Amplification is 2^n.
💡 Denature -> Anneal -> Extend (2^n)Sanger dideoxy sequencing incorporates 2',3'-dideoxynucleoside triphosphates (ddNTPs) which lack a 3'-OH group, terminating DNA chain elongation.
💡 ddNTP lacks 3'-OH -> Chain terminationBlue-white screening: Insertion into the lacZ' gene disrupts beta-galactosidase alpha-complementation; recombinant colonies cannot cleave X-gal and remain WHITE.
💡 White colonies = Recombinants with insertAgrobacterium tumefaciens Ti plasmid transfer: T-DNA is delimited by 25-bp direct repeats; virA/virG is a two-component sensor; virD1/D2 endonuclease cleaves T-DNA border; virE2 binds ssT-DNA.
💡 virA/G senses -> virD cuts -> virE coats T-DNACRISPR-Cas9 system: Cas9 endonuclease is guided by sgRNA (crRNA + tracrRNA) and requires a 5'-NGG-3' PAM (Protospacer Adjacent Motif) immediately 3' to target sequence to cleave DNA.
💡 sgRNA guide + NGG PAM sequence📚 Chapter-by-Chapter Rapid Cram Breakdown
10 ModulesHigh-density review of every curriculum chapter. Click any chapter title to view full in-depth lecture notes.
Scope and history →
- Master Classical versus molecular biotechnology: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master a defined change: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master Asilomar: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master Restriction–modification: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master ligase: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master PCR: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master cDNA: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master oligonucleotide synthesis: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
Vectors and cloning →
- Master Vector parts: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master insert size: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master expression hosts: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master genomic and cDNA libraries: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master Selection and blue–white screening: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master hybridisation and antibodies: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master sequencing and maps: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master blots and qPCR: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
Genome editing →
- Master Cre–lox: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master ZFNs and TALENs: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master CRISPR–Cas: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master delivery: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master germline versus somatic: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master Directed evolution: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master rational design: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master antibodies: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master heterologous pathways: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master biosensors: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master Primary and secondary metabolites: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master culture modes: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master strain improvement: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master products: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master bioremediation: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
Plant biotechnology →
- Master Ti plasmid: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master markers: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master commercial traits: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master Golden Rice: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master edits versus transgenes: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master Transgenics and knockouts: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master pharming: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master recombinant medicines: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master gene therapy: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master nuclear transfer: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master Biosafety levels: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master hazard and exposure: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master consent and germline editing: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master dual-use: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
- Master patents: understand underlying structural mechanisms, biochemical pathways, and diagnostic indicators.
⚖️ Must-Know Comparison & Distinction Tables
1 TablesSide-by-side matrices comparing commonly confused biological mechanisms, kinetic types, and pathways.
Molecular Cloning Vector Types & Capacity
| Vector Type | Host System | Insert Capacity | Key Features / Applications |
|---|---|---|---|
| Plasmid (e.g. pUC19, pBR322) | E. coli | 0.1 - 10 kb | High copy number, MCS, ampR/kanR markers, blue-white selection |
| Lambda Phage Replacement | E. coli | 10 - 23 kb | Packaged into lambda phage heads in vitro |
| Cosmid | E. coli | 30 - 45 kb | Plasmid carrying lambda cos sites for packaging; large genomic libraries |
| Bacterial Artificial Chromosome (BAC) | E. coli | 100 - 300 kb | Based on F-factor plasmid, low copy (1-2 per cell), stable for genome sequencing |
| Yeast Artificial Chromosome (YAC) | S. cerevisiae | 100 - 1000 kb (1 Mb) | Contains yeast centromere (CEN), telomeres (TEL), and autonomous replication (ARS) |
⚠️ Examiner Traps & Common Student Mistakes
1 PitfallsClassic trap questions designed by examiners to catch uncritical students. Don't lose easy marks here!
Taq Polymerase Proofreading Capability
Assuming Taq polymerase proofreads like human DNA polymerases.
Taq DNA polymerase (from Thermus aquaticus) LACKS 3' to 5' proofreading exonuclease activity. It also adds a non-templated single adenine (A) overhang to 3' ends (utilized in TA cloning vectors). For high-fidelity PCR, Pfu or Q5 polymerase is required.
📐 Key Formulas & Numerical Constants
2 FormulasStandard Equilibrium Constant
Keq = [Products] / [Reactants]Determines direction of chemical/biological reactions at dynamic equilibrium.
Relative Quantitative Ratio
Ratio = Experimental_Value / Baseline_ControlStandardizes comparative fold-change in quantitative biological assays.
🏛️ Landmark Scientists & Nobel Discoveries
6 PioneersFrequently tested in historical milestone and match-the-following exam questions.
Sir Alexander Fleming
🏅 Nobel Prize in Physiology or Medicine (1945) for the discovery of penicillin and its curative effect in various infectious diseasesMajor landmark discoveries
César Milstein
🏅 Nobel Prize in Physiology or Medicine (1984) for theories concerning the specificity in development and control of the immune system and the discovery of the principle for production of monoclonal antibodiesMajor landmark discoveries
Marc Van Montagu & Jozef Schell
🏅 World Food Prize (2013)Major landmark discoveries
Ingo Potrykus
Major landmark discoveries
Sir John Gurdon & Shinya Yamanaka
🏅 Nobel Prize in Physiology or Medicine (2012) for the discovery that mature cells can be reprogrammed to become pluripotentMajor landmark discoveries
Paul Berg
🏅 Nobel Prize in Chemistry (1980) for his fundamental studies of the biochemistry of nucleic acids, with particular regard to recombinant-DNAMajor landmark discoveries
🎯 Rapid-Fire Active Recall Checklist
3 QuestionsTest your memory before stepping into the exam hall. Try to answer mentally, then tap "Reveal Answer" to verify!