Molecular Genetics: Central Dogma, Mutations, and Bacterial Genetics

Vocabulary flashcards covering the Central Dogma, the genetic code, types of genetic mutations, and prokaryotic genetic markers and transformation.

Transformation

The uptake of DNA from the environment and its incorporation into the bacterial genome by recombination.

Prototrophic

A bacterial strain capable of synthesizing all required biochemicals (e.g., $Leu^+$ can synthesize leucine).

Auxotrophic

A bacterial strain with a biochemical dependency that requires a specific substance in the growth medium (e.g., $Leu^-$ requires leucine in the growth medium).

Streptomycin Sensitivity ($Str^S$)

A bacterial phenotype characterized by being killed or unable to grow in the presence of the antibiotic streptomycin.

Bacteriophage

Bacteria-infecting viruses used as genetic markers to evaluate bacterial resistance or sensitivity.

Mutation

A change in the genetic material, which can be large-scale (such as deletions, duplications, and changes in chromosome structure) or small-scale.

Point Mutation

A small-scale mutation that affects one or a few nucleotides ($NTs$).

Mis-sense Mutation

A point mutation that changes the encoded amino acid (e.g., changing codon $AAA$ [Lys] to $AAC$ [Asn]).

Non-sense Mutation

A point mutation that changes an amino acid codon into a stop codon (e.g., changing codon $AAA$ [Lys] to $TAA$ [Stop]).

Neutral Mutation (Silent Mutation)

A point mutation that results in no change to the encoded amino acid (e.g., changing codon $AAA$ [Lys] to $AAG$ [Lys]).

Frameshift Mutation

A mutation caused by the insertion or deletion of a few nucleotides ($NTs$) in a number not divisible by three, altering the downstream reading frame.

Central Dogma of Genetics

The framework describing the flow of genetic information: DNA (blueprint) is transcribed into mRNA (messenger), which is translated into a polypeptide (function), with reverse transcription converting RNA back into DNA.

Codon

A three-nucleotide sequence ('triplet code') in mRNA that specifies a particular amino acid or serves as a start or stop signal.

Degeneracy (Genetic Code)

The feature of the genetic code where multiple distinct codons can encode the same amino acid (e.g., $CC\_ = \text{Pro}$).

Wobble

Flexibility in pairing at the third nucleotide position of a codon, which gives rise to the degeneracy of the genetic code.