Microbiology Lecture – Bacterial Transformation

A set of 50 vocabulary flashcards covering key terms and definitions related to bacterial transformation.

Transformation (microbiology)

The process in which a living cell takes up DNA from an external source and incorporates it into its own genome.

Natural transformation

Spontaneous DNA uptake that occurs in certain bacteria directly from their environment without artificial intervention.

Artificial transformation

Laboratory-induced uptake of foreign DNA by cells using chemical or physical techniques.

Competence

A transient physiological state that enables a cell to bind and import extracellular DNA.

External DNA

DNA molecules located outside a cell that can be absorbed during transformation.

Genome integration

Insertion of acquired DNA into the host chromosome or plasmid, allowing stable inheritance.

Bacterial adaptation

Process by which bacteria gain new traits through gene acquisition, enhancing survival in changing conditions.

Electroporation

Artificial transformation method applying brief electrical pulses to create membrane pores for DNA entry.

Chemical transformation

Technique that uses chemical treatments, often calcium ions, to render cell membranes permeable to DNA.

Calcium chloride method

Classic chemical protocol that prepares Escherichia coli cells for DNA uptake using CaCl₂.

Heat shock

Rapid temperature shift that facilitates DNA passage into chemically treated cells.

Plasmid

Small, circular DNA molecule used as a vector to carry foreign genes during transformation.

Recombinant DNA

DNA engineered by combining genetic material from different sources into one molecule.

Host cell

Recipient cell that accepts and maintains foreign DNA following transformation.

Donor DNA

DNA fragments or plasmids supplied to recipient cells for potential uptake.

Gene function analysis

Use of transformation to study how specific genes influence cellular characteristics and behavior.

Protein expression

Production of proteins encoded by genes introduced through transformation.

Genetic engineering

Deliberate modification of an organism’s genetic material using techniques such as transformation.

Bioremediation

Use of genetically engineered microbes to break down or neutralize environmental pollutants.

Biofuel production

Generation of renewable fuels (e.g., ethanol, biodiesel) by microorganisms modified via transformation.

Insulin production

Large-scale microbial synthesis of human insulin enabled by transforming bacteria with the insulin gene.

Vaccine production

Manufacture of antigenic proteins in transformed microbes to create or enhance vaccines.

Gene therapy

Medical approach introducing functional genes into a patient’s cells to correct genetic disorders.

Pathogenicity factor

Molecule that enables bacteria to cause disease and can be transferred via transformation.

Antibiotic resistance gene

Selectable marker gene conferring drug resistance, used to identify successful transformants.

Selectable marker

Gene introduced with target DNA that allows researchers to detect or select transformed cells.

Transformation efficiency

Number of transformants obtained per microgram of DNA introduced.

Competence factor

Secreted protein or peptide that triggers development of competence in some bacterial species.

DNA uptake machinery

Set of membrane proteins mediating binding and transport of DNA into competent cells.

Double-stranded DNA binding protein

Protein that initially binds external double-stranded DNA during natural transformation.

Homologous recombination

Genetic mechanism inserting incoming DNA into the chromosome at regions of sequence similarity.

Horizontal gene transfer

Movement of genetic material between organisms other than by vertical inheritance; includes transformation.

Transformation frequency

Fraction of a bacterial population that becomes transformed under specific conditions.

Transformation buffer

Solution containing ions and stabilizers that promote DNA uptake during artificial transformation.

DNase sensitivity test

Assay showing that degradation of free DNA prevents transformation, confirming DNA is the transforming agent.

Uptake signal sequence

Short nucleotide motif that enhances recognition and uptake of DNA by certain competent bacteria.

Transformation protocol

Detailed experimental procedure outlining steps required to perform a transformation.

Competent cells

Laboratory-prepared bacteria capable of efficiently taking up foreign DNA.

Heat-labile DNA uptake

Temperature-sensitive stage during which DNA enters chemically treated cells; disrupted by excessive heat.

Chromosomal integration

Stable insertion of foreign DNA into the host’s chromosome after uptake.

Transformant

Cell that has successfully incorporated and can express foreign DNA acquired via transformation.

Environmental DNA

Genetic material released from dead or lysed organisms available for natural transformation.

Cell membrane permeability

Property altered in artificial transformation to allow DNA molecules to cross the membrane barrier.

Laboratory strain (E. coli DH5α)

Commonly used bacterial line engineered for high transformation efficiency and cloning work.

Shuttle vector

Plasmid engineered to replicate in two or more different host species, facilitating DNA transfer.

Reporter gene

Gene encoding an easily measurable product (e.g., GFP, lacZ) used to monitor transformation success.

Blue-white screening

Technique using the lacZ reporter to visually distinguish colonies with desired plasmid inserts after transformation.

Antibiotic selection plate

Agar medium containing antibiotics used to select cells that acquired resistance genes via transformation.

Incubation on ice

Cooling step that stabilizes cells before heat shock during chemical transformation protocols.

Recovery phase

Post-transformation incubation allowing cells to express selection markers before exposure to antibiotics.