unit 3 transcription

35問 • 1年前

問題一覧

Four major classes of rna produced by transcription

messenger rna, ribosomal rna, transfer rna, small nuclear rna

A class of rna molecules, each of which is complementary to one strand of dna, which carries the genetic message from the chromosome to the ribosome

messenger rna

Aclass of rna molecules seeving as components of ribosomes, the complexes that carry out protein synthesis

ribosomal rna

A class of rna molecules that faithfully translates information in mrna into a specific sequence of amino acids

transfer rna

Found only in eukaryotes, used in the processing of pre-mrna molecules

small nuclear rna

3’ to 5’ dna strand that serves as template for rna synthesis

template strand

5’ to 3’ dna strand that complementary to the template strand. Identical in base sequence to the rna transcribed in the gene, with u in the rna in place of t in the dna

nontemplate strand

Also called structural gene. A gene that codes for an mrna molecule, and hence for a protein

protein-coding gene

Three sequence of protein-coding gene

promoter, rna coding sequence, terminator sequence

A sequence adjacent to the start of the gene with which rna polymerase interacts. Upstream of the gene

promoter

The sequence of dna base pairs transcribe by rna polymerase into the single stranded mrna transcript

rna coding sequence

A sequence adjacent to the end of the gene that specifies where transcription will stop. Down stream from the gene

terminator

Consensus sequence found at the 35 region

TTGACA

Also called pribnow box. Consensus sequence located at the 10 region

TATAAT

A transcription regulatory sequence located at the distal end of a gene that signals the termination of transcription

terminator

Classes of termination signals

rho-dependent terminators and rho-independent terminators

Relies on protein factors called rho (p)

rho-dependent terminators

The core rna polymerase itself can carry out the termination events

rho-independent terminators

Eukaryotic cells have three distinct transcribing enzymes

rna polymerase 1, rna polymerase 2, rna polymerase 3

Synthesizes the pre-ribosomal rna, which contains the precursor for the 18S, 5.8S, and 28S rrna

rna polymerase 1

Synthesizes mrna and most small nuclear rnas

rna polymerase 2

Synthesizes trna, 5S rrna, and U6 snrna

rna polymerase 3

Specific proteins required for the iniation of transcription by a eukaryotic rna polymerase

transcription factors

Proteins involved in the activation or repression of transcription of the gene

regulatory factors

Activate transcription

positive regulatory elements

Repress transcription

negative regulatory elements

A dna sequence at which rna polymerase may bind, leading to initiation of transcription

promoter

A regulatory site in the dna that may be located at considerable distance either upstream or downstream from the promoter that it regulates

enhancer

A transcriptional regulatory element that deceeases rna transcription rather than stimulating it like other enhancer elements

silencer

Regulatory elements in yeast that are functionally dimilarbto enhancers in other eukaryotes. They can function in either orientation and at variable distances upstream of the promoter

upstream activator sequences

Promoter elements

CAAT box, GC box, TATA box

Eukaryotic promoter element approximately 80 bp upstream of the initiation site, but it can function at a number of locations and in either orientation with respect to the start point

CAAT box

A eukaryotic promoter element with the consensus sequence GGGCGG

GC box

Also called the goldberg-hogness box. Considered to be likely eukaryotic promoter sequence

TATA box

Removal of introns

splicing

histology unit 1

ユーザ名非公開 · 49問 · 1年前

histology unit 1