12. Gene Transcription and RNA Modification Flashcards
the process of synthesizing RNA from a DNA template.
Transcription
a segment of DNA that contains the information to make a functional product, either RNA or a polypeptide.
Gene
genes that produce mRNA and encode polypeptides
Protein-Coding (Structural) Genes
a type of RNA that is transcribed from a protein-encoding gene and contains the information for the synthesis of a polypeptide.
Messenger RNA (mRNA)
the process in which the sequence of codons within mRNA provides the information to synthesize the sequence of amino acids that constitute a polypeptide.
Translation
the idea that the usual flow of genetic information is from DNA to RNA to polypeptide (protein). In addition, DNA replication serves to copy the information so that it can be transmitted from cell to cell and from parent to offspring.
Central Dogma of Genetic
the process by which the information within a gene is accessed, first to synthesize RNA and polypeptides, and eventually to affect the phenotype of the organism.
Gene Expression
a sequence within a gene that initiates (i.e., promotes) transcription.
Promoter
a sequence within a gene that signals the end of transcription.
Terminator
a strand of DNA that is used to synthesize a complementary strand of DNA or RNA.
Template Strand
a strand of DNA that is not used as a template during transcription.
Nontemplate Strand
the strand in DNA that is not used as a template for mRNA synthesis.
Coding (Sense) Strand
a category of proteins that influence the ability of RNA polymerase to transcribe DNA into RNA.
Transcription Factors
a segment of DNA that is recognized by a regulatory transcription factor. The binding of the transcription factor affects the rate of transcription.
Regulatory Sequence (Element)
a short sequence in bacterial mRNA that binds to a ribosome and initiates translation.
Ribosome-Binding Site (Shine-Dalgarno Sequence)
a sequence of three nucleotides in mRNA that functions in translation.
Codon
a three-base sequence in mRNA that initiates translation. It is usually 5′-AUG-3′ and encodes methionine.
Start Codon
a three-base sequence in mRNA that signals the end of translation of a polypeptide. The three are 5′–UAA–3′, 5′–UAG–3′, and 5′–UGA–3′.
Stop Codon
(1) in transcription, the stage that involves the initial binding of RNA polymerase to the promoter in order to begin RNA synthesis; (2) in translation, the formation of a complex between mRNA, the initiator tRNA, and the ribosomal subunits.
Initiation
(1) in transcription, the release of the newly made RNA transcript and RNA polymerase from the DNA; (2) in translation, the release of the polypeptide and the last tRNA and the disassembly of the ribosomal subunits and mRNA.
Termination
an enzyme that synthesizes a strand of RNA using a DNA strand as a template.
RNA Polymerase
the region of separation of two DNA strands produced by RNA polymerase during transcription.
Open Complex
the site in a gene where transcription begins.
Transcriptional Start Site
the TATAAT sequence that is often found at the −10 site of a bacterial promoter.
Pribnow Box
the most commonly occurring bases within a specific type of sequence.
Consensus Sequence
an enzyme composed of subunits that are needed for catalytic activity, as in the core enzyme of RNA polymerase.
Core Enzyme
a transcription factor that recognizes bacterial promoter sequences and facilitates the binding of RNA polymerase to the promoter.
Sigma (σ) Factor