Biotechnology
rDNA Technology Steps (RICE) — Remember Restriction enzyme cutting → Insertion of gene → Cloning in vector → Expression in host. This sequence covers the four core steps of recombinant DNA technology for NSEB questions.
Competent Cells (CaCl₂ = Calcium) — Bacterial cells treated with Calcium chloride become capable of taking up DNA. The "Ca-Ca" link helps recall that CaCl₂ makes cells competent for transformation.
PCR Three Temps (9-5-7) — Denaturation at ~95°C, Annealing at ~55°C, Extension at ~72°C. The "9-5-7" descending pattern matches the three temperature steps in each PCR cycle.
Plasmid Features (ORIS) — Ori (origin of replication), Resistance gene (selectable marker), Insertion site (restriction site), Small size. Essential plasmid vector characteristics tested frequently.
Cell Structure and Function
Mitochondrial Membranes (COPS) — Cristae (inner folds), Oxysomes/ATP synthase, Porins (outer membrane), Space between = intermembrane space. Captures key mitochondrial membrane features.
Lysosome = Suicide Bag (Acid pH) — Lysosomes maintain pH ~4.5-5.0 using proton pumps; if membrane ruptures, acidic hydrolases digest the cell itself, hence "suicide bag" coined by de Duve.
Plastid Types (CLC) — Chloroplasts (green/photosynthesis), Leucoplasts (colorless/storage), Chromoplasts (colored/pigments). Covers the three main plastid categories with color cues.
Biomolecules
Essential Amino Acids (PVT TIM HALL) — Phenylalanine, Valine, Threonine, Tryptophan, Isoleucine, Methionine, Histidine, Arginine, Leucine, Lysine. Ten essential amino acids humans cannot synthesize.
Reducing Sugars (All Mono +MAL) — All monosaccharides + Maltose, lActose, but NOT sucrose. Sucrose is non-reducing because both anomeric carbons are locked in glycosidic bond.
Pyrimidines = CUT — Cytosine, Uracil, Thymine are single-ring pyrimidines. Purines (AG) are double-ring; "CUT the PY(rimidine)" helps separate them.
Cell Cycle and Division
Interphase Duration (G₁ > S > G₂) — G₁ is longest, S (synthesis) intermediate, G₂ shortest in most cells. Typical ratios help estimate phase duration from total cycle time questions.