Transcription and Translation

Flashcards covering key concepts related to transcription and translation processes in molecular biology.

Transcription

The process of synthesizing an RNA version of the instructions stored in DNA.

RNA polymerase

An enzyme that performs transcription by synthesizing RNA from a DNA template.

Template strand

The strand of DNA that RNA polymerase uses as a guide to synthesize RNA.

Non-template (coding) strand

The DNA strand that matches the sequence of mRNA, except for thymine (T) being replaced by uracil (U).

Holoenzyme

A complex of an enzyme with its required co-factors, including a core enzyme and sigma protein in prokaryotes.

Sigma

A protein subunit that binds to RNA polymerase and helps it to recognize promoter sequences on DNA.

Promoter

A specific DNA sequence that signals the start of transcription.

Eukaryotic promoters

More diverse and complex than bacterial promoters; often contain a TATA box.

Introns

Noncoding sequences in eukaryotic genes that are removed during RNA processing.

Exons

The coding regions of eukaryotic genes that are retained in the mature mRNA.

Translation

The process of converting the sequence of bases in mRNA into an amino acid sequence in a protein.

tRNA (transfer RNA)

Molecules that carry amino acids to the ribosome and have anticodons that base-pair with mRNA codons.

Ribosomes

Molecular machines that catalyze the translation of mRNA into proteins.

Codon

A sequence of three nucleotide bases in mRNA that specifies an amino acid.

AUG start codon

The codon that signals the start of translation.

Elongation phase

The stage of translation where amino acids are added to the growing polypeptide chain.

Termination phase

The final stage of translation that occurs when a stop codon is encountered.