ch.12

Central Dogma of Molecular Genetics

Describes the flow of genetic information from DNA to RNA to proteins.

Transcription

The synthesis of RNA from a DNA template to produce an RNA copy of a gene.

Messenger RNA (mRNA)

A type of RNA that serves as a temporary copy of a gene that can be translated into polypeptides.

Promoter

DNA sequence where RNA polymerase binds to initiate transcription.

Terminator

Sequence signaling the end of transcription.

5' UTR

Untranslated region critical for translation initiation.

Polyadenylation

A tail of adenine nucleotides added to the 3' end of mRNA enhancing stability and translation efficiency.

Splicing

The process of removing introns and joining exons in RNA.

Rho-dependent Mechanism

Termination mechanism where the ρ protein separates the RNA-DNA hybrid at the termination site.

Allosteric Model

Model where RNA Pol II dissociates post-transcription of the polyadenylation signal.

DNase Footprinting

Technique used to identify protein-binding regions in DNA by observing cleavage patterns.

RNA Polymerase II

Enzyme responsible for synthesizing mRNA, snRNA, miRNA, and telomerase RNA.

5' Capping

Addition of a 7-methylguanosine cap to the 5' end of mRNA facilitating splicing and translation.

Alternative Splicing

Allows differential production of proteins from a single mRNA based on which exons are included.

Northern Blot

Method used to detect specific RNA sequences in a sample via gel electrophoresis and hybridization.

Initiation of Transcription

RNA polymerase binds to the promoter, forming a closed complex before transitioning to an open complex.

Elongation in Transcription

RNA polymerase synthesizes RNA by unwinding the DNA template and adding nucleotide triphosphates (NTPs) in the 5' to 3' direction.

Termination of Transcription

RNA polymerase reaches the termination sequence, causing the release of the new RNA transcript.

Messenger RNA (mRNA)

Encodes amino acid sequences, generally monocistronic in eukaryotes.

Ribosomal RNA (rRNA)

Structural and functional components of ribosomes.

Transfer RNA (tRNA)

Transfers specific amino acids during translation.

Small Nuclear RNA (snRNA)

Involved in splicing introns from pre-mRNA.

MicroRNA (miRNA)

Regulates gene expression by interfering with mRNA stability.

Small Interfering RNA (siRNA)

Regulates gene expression and maintains genome integrity.

Telomerase RNA

Part of the telomerase complex, necessary for telomere maintenance.

DNA Replication

The process where DNA makes copies of itself; essential for cell division and hereditary transmission.

Gene

A unit of heredity, represented by chromosomal DNA, that encodes the necessary information for creating proteins.

Transcription

The synthesis of RNA from a DNA template to produce an RNA copy of a gene.

Messenger RNA (mRNA)

A type of RNA that serves as a temporary copy of a gene that can be translated into polypeptides.

Translation

The process whereby the information in mRNA is used to synthesize polypeptides, which form functional proteins contributing to phenotypic traits in organisms.

RNA Polymerase I (RNA Pol I)

Makes ribosomal RNA (rRNA), except for the 5S type.

RNA Polymerase II (RNA Pol II)

Creates messenger RNA (mRNA), small nuclear RNA (snRNA), microRNA (miRNA), and telomerase RNA.

RNA Polymerase III (RNA Pol III)

Produces transfer RNA (tRNA), 5S ribosomal RNA (5S rRNA), small nuclear RNA (snRNA), and small interfering RNA (siRNA).

Torpedo Model

An exonuclease attaches to the 5' end of the growing RNA and breaks it down until it reaches RNA Pol II, ending transcription.

3' Polyadenylation

A tail of adenine nucleotides (up to 250 A's) added to the 3' end to improve RNA stability and help with translation.

Band Shift Assay

A technique used to analyze protein-DNA interactions; slower migration in a gel indicates the presence of bound proteins to DNA.