Genetics: Central Dogma, Mutations, and Bacterial Genetics

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

Central Dogma of Genetics

The framework describing the flow of genetic information: DNA (blueprint) is transcribed into mRNA (messenger), which is then translated into a functional polypeptide.

Transcription

The enzymatic process of synthesizing an RNA molecule (such as mRNA, tRNA, rRNA, snRNA, or piRNA) from a DNA template.

Translation

The process by which the sequence of an mRNA molecule is used to direct the synthesis of a specific polypeptide sequence in the cytoplasm.

Codon

A discrete, three-nucleotide-long sequence in mRNA that specifies a particular amino acid or serves as a start or stop signal in protein synthesis.

Degenerate Code

A feature of the genetic code where multiple distinct codons can encode the exact same amino acid (for example, CC_ encoding Proline).

Wobble

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

Mutation

A change in the genetic material, which can occur on a large scale (such as deletions, duplications, or chromosome structure changes) or a small scale.

Point Mutation

A small-scale mutation that alters, inserts, or deletes only one or a few nucleotides in the DNA sequence.

Mis-sense Mutation

A point mutation that changes a codon so that it encodes a different amino acid than originally specified (e.g., AAA encoding Lys changing to AAC encoding Asn).

Non-sense Mutation

A point mutation that converts an amino acid-specifying codon into a premature stop codon (e.g., AAA encoding Lys changing to TAA encoding a stop signal).

Neutral Mutation (Silent Mutation)

A point mutation that changes a codon without changing the encoded amino acid (e.g., AAA mutating to AAG, both specifying Lys).

Frameshift Mutation

The insertion or deletion of a number of nucleotides that is not a multiple of three, altering the translational reading frame downstream.

Prototrophic

A bacterial strain capable of synthesizing all essential biochemical compounds needed for its growth, without requiring specific nutrient supplements.

Auxotrophic

A mutant bacterial strain that exhibits a biochemical dependency, requiring specific biochemical nutrients (e.g., leucine in a $Leu^-$ mutant) to be provided in the growth medium.

Bacteriophage

Viruses that specifically infect bacterial cells.

Transformation

A mechanism of introducing foreign DNA into a bacterial cell via direct uptake of DNA from the surrounding environment followed by incorporation into the bacterial genome by recombination.