biol215 study

Transforming Principle

The concept that a heat-stable component from virulent bacteria can transform avirulent bacteria into virulent forms.

S-strain

A virulent strain of Streptococcus pneumoniae characterized by a smooth appearance due to a polysaccharide capsule.

R-strain

An avirulent strain of Streptococcus pneumoniae that appears rough and lacks a protective capsule.

Griffith's Experiment

An experiment in 1928 that demonstrated the transformation of R-strain bacteria into S-strain through the introduction of heat-killed S-strain.

Avery, MacLeod, and McCarty

Researchers who identified DNA as the transforming principle in 1944 by fractionating the components of heat-killed S-strain bacteria.

DNase Treatment

A treatment that destroyed DNA, resulting in no transformation of R-strain bacteria, indicating DNA's role in transformation.

Hershey and Chase Experiment 1953

An experiment that used radioactive labeling of T2 phages (32P and 35S) to demonstrate that DNA, not protein, is the genetic material, following the passing of genetic material from parent to offspring.

Agarose Gel Electrophoresis

A technique used to separate DNA fragments based on size, where negatively charged DNA migrates towards the positive electrode.

Spectrophotometry

A method to measure DNA concentration and purity by checking absorbance at specific wavelengths (260/280 nm).

Restriction Enzymes

Enzymes that cut DNA at specific sequences, producing fragments with 'sticky' or 'blunt' ends for cloning purposes.

Sanger Sequencing

A method of DNA sequencing that uses dideoxynucleotides to terminate DNA synthesis, allowing for the determination of DNA sequences.

BLAST Search

An online tool used to find regions of similarity between biological sequences, useful for gene identification.

ORF Finder

A tool used to identify open reading frames in DNA sequences, aiding in gene prediction and protein expression studies.

PCR (Polymerase Chain Reaction)

A technique used to amplify specific DNA sequences through repeated cycles of denaturation 95º , annealing 45º, and extension 72º.

Southern Blot

A method for detecting specific DNA sequences in DNA samples by transferring fragments from a gel to a membrane and hybridizing with a labeled probe.

Northern Blot

A technique similar to Southern blotting but used for detecting RNA instead of DNA, useful for studying gene expression.

Microarray Technology

A method that allows simultaneous analysis of thousands of genes, useful for detecting mutations and gene expression profiling.

Horizontal Gene Transfer

The transfer of genetic material between organisms of different species, including methods like conjugation, transformation, and transduction.

Competence

The ability of bacteria to take up extracellular DNA, which can be natural or induced through various methods.

Virulence Factors

Traits that enable bacteria to infect hosts, including adherence, invasion, and evasion of host defenses.