Mutations and Transcription

Flashcards reviewing mutations, transcription, and related concepts from the lecture notes.

Mutation

A change in the DNA sequence that can lead to new alleles.

Point Mutation

A change in a single base within a DNA sequence (e.g., A to T).

Insertion (Mutation)

The addition of a base into a DNA sequence, causing a shift in the reading frame.

Deletion (Mutation)

The removal of a base from a DNA sequence, causing a shift in the reading frame.

Silent Mutation

A change in the DNA sequence that does not alter the amino acid sequence due to the redundancy of the genetic code.

Missense Mutation

A base change that results in a codon that codes for a different amino acid.

Nonsense Mutation

A base change that results in a stop codon, leading to premature termination of translation.

Frameshift Mutation

Insertions or deletions that shift the reading frame, changing all subsequent amino acids.

Beneficial Mutation

A mutation that enhances an organism's ability to survive and reproduce.

Neutral Mutation

A mutation that does not affect an organism's fitness.

Deleterious Mutation

A mutation that decreases an organism's ability to survive and reproduce.

Polyploidy

A mutation affecting the number of each type of chromosome, resulting in more than two of each type.

Aneuploidy

The loss or gain of a whole chromosome.

Inversion (Chromosome)

A piece of a chromosome breaks off, flips around, and reattaches.

Translocation (Chromosome)

A piece of one chromosome breaks off and attaches to another chromosome.

Karyotype

A picture where all the different chromosomes are labeled.

Transcription

The process of making RNA from a DNA template.

Translation

The process of making proteins from an RNA template.

RNA Polymerase

The enzyme responsible for making RNA.

Template Strand

The strand of DNA used by RNA polymerase to create a complementary RNA transcript.

Non-template Strand (Coding Strand)

The strand of DNA that has the same sequence as the RNA transcript (except with uracil instead of thymine).

Initiation (Transcription)

The first phase of transcription, where RNA polymerase binds to the promoter with the help of sigma (in bacteria) or basal transcription factors (in eukaryotes).

Sigma Protein

A protein in bacteria that binds to the promoter region of DNA and helps RNA polymerase initiate transcription.

Promoter

A region of DNA that initiates transcription of a particular gene.

Minus 10 Box

A region in the promoter located approximately 10 nucleotides upstream from the transcription start site, commonly containing the sequence TATAAT.

Minus 35 Box

A region in the promoter located approximately 35 nucleotides upstream from the transcription start site, commonly containing the sequence TTGACA.

Elongation (Transcription)

The second phase of transcription, where RNA polymerase moves along the DNA template, synthesizing RNA in the 5' to 3' direction.

Termination (Transcription)

The final phase of transcription, where RNA polymerase detaches from the DNA template, releasing the RNA transcript.

Transcription Termination Signal

A sequence in bacteria that forms a hairpin loop, causing RNA polymerase to detach and terminate transcription.

Poly A Signal

A long string of adenine bases transcribed in eukaryotes, signaling the end of transcription.

Basal Transcription Factors

A diverse array of transcription factors in eukaryotes that allow for fine-tuned regulation of genes.