BSEH SS Biotechnology flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Biotechnology

Use of living organisms, cells, or their components to produce goods or services, spanning classical fermentation and modern recombinant DNA applications in health, agriculture, and industry.

Bioinformatics

Computational discipline that stores, aligns, and analyses biological sequence and structural data, enabling genome annotation, database searches such as BLAST, and evolutionary comparisons.

Fluid mosaic model

Description of the plasma membrane as a phospholipid bilayer with embedded proteins, cholesterol, and glycolipids that move laterally, giving the membrane selective permeability and dynamic behaviour.

Michaelis constant Km

Substrate concentration at which an enzyme reaches half its maximum velocity; a low Km indicates high substrate affinity, while Vmax reflects enzyme amount and turnover.

Central dogma

Principle that genetic information flows from DNA to RNA during transcription and from RNA to protein during translation, with reverse transcription as a known exception in retroviruses.

Lac operon

Inducible bacterial gene system controlled by a repressor; lactose metabolite inactivates the repressor, allowing transcription of lactose-utilizing genes, while glucose causes catabolite repression.

Restriction endonuclease

Enzyme that recognizes a specific palindromic DNA sequence and cleaves it, producing sticky or blunt ends used to cut inserts and vectors in cloning.

Polymerase chain reaction

In vitro method that amplifies DNA through repeated cycles of denaturation, primer annealing, and extension by a thermostable polymerase, doubling target copies each cycle.

CRISPR-Cas9

Genome-editing system in which a guide RNA directs the Cas9 nuclease to a target sequence next to a PAM site, creating a double-strand break for knockout or repair.

Bacterial growth curve

Plot of cell number over time showing lag, exponential, stationary, and decline phases, reflecting adaptation, rapid division, nutrient limitation, and cell death.

Autoclave sterilization

Steam sterilization at about 121 degrees Celsius and 15 psi for 15 to 20 minutes, which kills all microorganisms including bacterial endospores.

Gram stain

Differential staining using crystal violet, iodine, alcohol, and safranin; Gram-positive cells retain purple due to thick peptidoglycan, while Gram-negative cells appear pink.

Totipotency

Capacity of a plant cell to divide and regenerate a complete plant under suitable hormone conditions, the basis of micropropagation and tissue culture.

Callus

Undifferentiated mass of plant cells formed from an explant on medium with balanced auxin and cytokinin, used as starting material for regeneration or suspension cultures.

Hybridoma

Fused cell formed from a B lymphocyte and a myeloma cell, combining antibody specificity with unlimited division to produce monoclonal antibodies.

Monoclonal antibody

Antibody produced by a single cloned cell line, binding one specific epitope with uniform specificity, widely used in diagnostics, therapy, and research.

ELISA

Enzyme-linked immunosorbent assay that detects antigen or antibody through an enzyme-labelled reagent converting substrate to a measurable colour signal, in direct, indirect, sandwich, or competitive formats.

Passive immunity

Protection acquired by transfer of ready-made antibodies, as from mother to fetus across the placenta or through immunoglobulin therapy, without active immune memory.

Bt crop

Transgenic plant carrying Bacillus thuringiensis cry genes that produce insecticidal crystal proteins toxic to specific insect larvae but harmless to mammals.

Biofortification

Breeding or genetic engineering of staple crops to increase content of essential nutrients such as provitamin A, iron, or zinc, improving nutrition in target populations.

Immobilized enzyme

Enzyme attached to a solid support or entrapped in a matrix, allowing reuse, easy separation from product, and continuous operation in industrial processes.

Biosafety level

Classification of laboratory containment from BSL-1 to BSL-4 based on agent risk, specifying practices, equipment, and facility design needed to prevent exposure and release.

TRIPS Agreement

World Trade Organization agreement on intellectual property that requires patent protection for microorganisms and microbiological processes while permitting some exclusions for plants and animals.

Biopiracy

Unauthorized commercial exploitation of biological resources or traditional knowledge without consent or fair benefit-sharing with the source country or community.

Beer-Lambert law

Relationship stating absorbance equals molar absorptivity times concentration times path length, used to quantify nucleic acids and proteins spectrophotometrically.

Serial dilution

Stepwise dilution in which each transfer reduces concentration by a fixed factor, producing a geometric series used for viable counts and standard curves.

Agarose gel electrophoresis

Technique separating DNA fragments by size as negatively charged molecules migrate toward the anode through a gel matrix, with smaller fragments moving faster.

Aseptic technique

Set of practices such as flaming loops, using sterile media, and working near a flame or laminar flow that prevent contamination of cultures and samples.

Plasmid vector

Small circular extrachromosomal DNA engineered with an origin of replication, selectable marker, and cloning site to carry and replicate foreign DNA in a host cell.

Southern blot

Method that transfers size-separated DNA from a gel to a membrane and detects specific sequences with a labelled probe, used in cloning verification and fingerprinting.

Competent cells

Bacterial cells treated chemically or electrically to transiently take up exogenous DNA during transformation, enabling plasmid introduction in cloning workflows.

Selectable marker

Gene in a vector conferring a trait such as antibiotic resistance, allowing only cells that acquired the vector to grow on selective medium.