Molecular Biology I - Transformation and Genetics Study Guide

A collection of 60 vocabulary flashcards covering key concepts from Molecular Biology I, focusing on transformation, genetics, PCR, and related laboratory techniques.

GFP

Green fluorescent protein that glows green when stimulated with ultraviolet light, used as a marker for transformed cells.

Ampicillin resistance

A gene that confers resistance to the antibiotic ampicillin, allowing only transformed cells to survive.

Transformation efficiency

The number of transformants per microgram (µg) of DNA used in transformation.

Transformation

The uptake of DNA by bacterial cells from the surrounding environment, leading to genetic alteration.

CaCl2

Calcium chloride, a reagent used to make bacterial cells competent to take up DNA.

Heat shock

A process where bacterial cells are subjected to rapid temperature changes to increase DNA uptake.

Taq polymerase

A thermostable enzyme used in PCR that synthesizes new DNA strands by adding nucleotides.

Denaturation (PCR)

The first step in PCR, where DNA is heated to 94°C to separate the strands.

Annealing (PCR)

The second step in PCR, where primers bind to the DNA sequences at lower temperatures.

Extension (PCR)

The third step in PCR, where Taq polymerase adds nucleotides to synthesize new DNA strands.

dNTPs

Deoxynucleotide triphosphates, the building blocks used by polymerase to create new DNA strands during PCR.

Template DNA

The DNA that is copied during the PCR process.

Primers

Short sequences of nucleotides that provide a starting point for DNA synthesis in PCR.

Electrophoresis

A technique used to separate DNA fragments based on size through a gel matrix.

Restriction enzymes

Proteins that cut DNA at specific sequences, often used in genetic engineering.

Palindromic site

A DNA sequence that reads the same forwards and backwards on complementary strands.

Alleles

Different versions of a gene that can exist at a specific locus on a chromosome.

Phosphodiester bonds

Covalent bonds that link nucleotides together in a DNA strand.

Competent cells

Bacterial cells that are capable of taking up foreign DNA.

Electrocompetent cells

Bacterial cells made competent through electroporation, allowing DNA uptake.

Transformed cells

Bacterial cells that have successfully taken up and expressed foreign DNA.

PCR cycles

The number of times the PCR steps are repeated to amplify DNA; the number of product copies is calculated as 2^n.

Copes for n cycles

The total number of DNA products produced through PCR after n cycles is given by 2^n.

Phenotype

The observable characteristics or traits of an organism, influenced by genotype.

Genotype

The genetic makeup of an organism, describing the specific alleles present.

Punnett square

A diagram used to predict the genotypes and phenotypes of offspring from parental genetics.

Brown pigment in flies

Produced by the interaction of scarlet and white proteins transferring precursors into granules.

Scarlet pigment in flies

Produced by the interaction of brown and white proteins transferring precursors into granules.

White eyes in flies

Result of mutations in both brown and scarlet genes, leading to a lack of pigment production.

Brick red eyes in flies

Result of normal alleles for both brown and scarlet genes, allowing both pigments to be produced.

Wild type

The typical or most common phenotype in a population, often referring to the non-mutated version of a gene.

Recessive alleles

Alleles that do not manifest phenotypically unless both copies are present as mutant.

X-linked genes

Genes located on the X chromosome, which can affect sex-specific traits and inheritance.

Transformation efficiency calculation

Number of colonies divided by the amount of DNA (in µg) used in transformation.

GEL electrophoresis

A method for separating DNA fragments on a gel based on their size.

Overhangs

Short single-stranded tails that can be left after DNA cleavage by restriction enzymes.

Blunt ends

DNA ends that do not have any overhangs; produced by certain restriction enzymes.

Colony counting

A method to determine how many transformed bacterial cells are present on a culture plate.

Colony formation

The outcome of a single transformed cell dividing multiple times to form a visible colony.

High agarose concentration

Used in gel electrophoresis to better separate small DNA fragments.

Low agarose concentration

Used in gel electrophoresis to better separate large DNA fragments.

Scarlet eyes phenotype

Seen in flies with two recessive st alleles (st/st) with functional brown alleles.

Brown eyes phenotype

Seen in flies with both brown alleles (bw/bw) that do not express scarlet pigment.

White flies phenotype

Seen in flies with mutations in both bw and st, failing to produce any pigments.

PCR template preparation

The process of preparing DNA that needs to be amplified in PCR.

Antibiotic selection

Process of choosing transformed cells by plating with antibiotic; only those that took up the plasmid survive.

GFP expression

Visualization of transformed cells based on the green fluorescence under UV light.

Electrophoretic mobility

The rate at which molecules move through a gel matrix, influenced by their size and charge.

Allelic restriction analysis

Using restriction enzymes to differentiate between alleles based on their cut sites.

DNA migration in gel

The movement of DNA in electrophoresis towards the positive electrode; smaller fragments move faster.

Primer melting temperature

The temperature at which half of the DNA strands are in the double helix and half are in the

single-stranded state

Indicates the stability of the primer binding to the target sequence during PCR.

ssDNA

Single-stranded DNA, which results from the denaturation step of PCR.