Unit 13: The DNA and Protein Synthesis - Lesson 13.3: Transcription

These flashcards cover key concepts related to DNA transcription and the role of RNA in protein synthesis, providing definitions and explanations pertinent to the lesson.

Transcription

The process of producing RNA as directed by the DNA in the nucleus.

Messenger RNA (mRNA)

Carries the genetic sequence information from DNA to ribosomes for protein synthesis.

Ribosomal RNA (rRNA)

A major component of ribosomes that catalyzes peptide bond formation during protein synthesis.

Transfer RNA (tRNA)

Serves as carrier molecules for amino acids during protein synthesis.

RNA Polymerase

The enzyme that unwinds DNA and synthesizes RNA during transcription.

Template Strand

The strand of DNA that is used as a guide for synthesizing the complementary mRNA strand.

Coding Strand

The strand of DNA that has the same sequence as the mRNA, except for thymine which is replaced by uracil.

Exons

The coding sequences of RNA that remain in the mature mRNA after splicing.

Introns

The noncoding sequences of RNA that are removed during splicing.

Post-Transcriptional Modifications

Changes made to the pre-mRNA before it becomes mature, including capping, tailing, and splicing.

Guanosine Triphosphate (GTP) Cap

A modification added to the 5’ end of mRNA which helps protect it and assists in ribosome binding.

Poly-A Tail

A sequence of adenine nucleotides added to the 3’ end of mRNA that stabilizes and aids in export from the nucleus.

Initiation

The first stage of transcription where RNA polymerase binds to the promoter and starts RNA synthesis.

Elongation

The second stage of transcription where RNA polymerase extends the growing mRNA strand.

Termination

The final stage of transcription where RNA synthesis stops upon reaching the terminator sequence.

The Central Dogma

The framework describing the flow of genetic information from DNA to RNA to proteins.

Hairpin Structure

A loop-like formation that can occur in RNA after transcription, often due to complementary regions binding.

Promoter Region

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

Transcription Bubble

The localized unwinding of the DNA helix that occurs during transcription.

mRNA Transcript

The initial RNA strand synthesized during transcription which needs further processing before translation.