Transcription and mRNA Processing - Vocabulary

Vocabulary flashcards covering key terms in transcription and mRNA processing from the notes.

Amino acid

The building blocks of proteins; 20 standard types with an amino group and a carboxyl group, encoded by codons.

Protein

A macromolecule made of one or more polypeptides folded into a functional three-dimensional structure.

Gene

A DNA sequence that codes for a functional product, usually a protein or functional RNA (tRNA, rRNA, etc.).

mRNA (messenger RNA)

RNA that carries genetic information from DNA to the ribosome for translation.

tRNA (transfer RNA)

RNA that delivers specific amino acids to the ribosome during protein synthesis.

rRNA (ribosomal RNA)

RNA component of the ribosome that helps catalyze protein synthesis.

Promoter

DNA sequence where RNA polymerase binds to initiate transcription.

RNA polymerase

Enzyme that synthesizes RNA using a DNA template.

Pre-mRNA

The initial RNA transcript produced from DNA that must be processed to become mature mRNA.

Transcription

The process of copying a DNA sequence into an RNA molecule.

Initiation (transcription)

Stage when RNA polymerase binds the promoter to start RNA synthesis.

Elongation (transcription)

Phase in which the RNA chain grows as nucleotides are added; the template DNA strand is read 3' → 5'.

Template strand

The DNA strand used as the template for RNA synthesis; RNA is complementary to this strand.

Terminator

DNA sequence near the end of a gene that signals transcription termination.

5' to 3' transcription direction

RNA is synthesized in the 5' to 3' direction; the DNA template is read 3' to 5'.

Exon

Coding region of a gene that remains in mature mRNA after splicing.

Intron

Noncoding region of a gene that is removed during RNA processing.

RNA splicing

Process of removing introns and joining exons to produce mature mRNA.

Alternative splicing

Process by which different exon combinations produce multiple mRNA variants from one gene.

5' cap

Modified guanine nucleotide with three phosphates added to the 5' end of eukaryotic mRNA to stabilize and aid ribosome binding.

Poly(A) tail

Tail of adenine nucleotides added to the 3' end (~200 in humans) to protect mRNA and assist export/translation.

Mature mRNA

Processed mRNA with a 5' cap, introns removed, and a 3' poly(A) tail; ready for translation.

Prokaryotic mRNA processing

In prokaryotes, transcription and translation are coupled; transcripts typically lack introns and extensive processing.