DNA Transcription and RNA Processing

These flashcards cover key terms related to DNA transcription, RNA processing, and the genetic code for a comprehensive review.

Transcription

The process of synthesizing RNA from a DNA template.

RNA polymerase

An enzyme that catalyzes the synthesis of RNA using a DNA template.

Promoter

A specific DNA sequence where RNA polymerase binds to initiate transcription.

Holoenzyme

The complete and active form of RNA polymerase, consisting of the core enzyme and additional factors.

Cis-acting elements

Regulatory DNA sequences that influence the transcription of nearby genes.

Trans-acting factors

Proteins, such as transcription factors, that bind to cis-acting elements to regulate gene expression.

Intron

Non-coding regions of a gene that are removed during RNA processing.

Exon

Coding regions of a gene that are retained in the mature mRNA after splicing.

5’-end capping

The addition of a modified guanine nucleotide at the 5' end of mRNA for protection and initiation of translation.

Poly-A tail

A stretch of adenine nucleotides added to the 3' end of mRNA to stabilize it and facilitate export from the nucleus.

Alternative splicing

The process by which different combinations of exons are joined together, resulting in multiple mRNA variants from a single gene.

Transcription termination

The final stage of transcription where RNA polymerase detaches from the DNA, often signaled by specific sequences or structures.

Open Reading Frame (ORF)

A continuous stretch of codons that begins with a start codon and ends before a stop codon.

Codon

A set of three nucleotides in mRNA that encodes a specific amino acid.

Sense strand

The DNA strand that has the same sequence as the mRNA transcript (except for thymine, which is replaced by uracil in RNA).

Antisense strand

The DNA strand that serves as the template for RNA synthesis.