Chapter 14: Gene transcription and RNA modification

The transcriptional start site is denoted ______.

+1

The TATA box of eukaryotic genes is usually located about ______ from the transcriptional start site.

25 bp upstream

What is a promoter?

A specific target sequence to which RNA polymerase binds.

The low level of transcription caused by the presence of the core promoter by itself is known as ____ transcription.

Basal

Fill in the blank question. Transcription in E. coli is initiated when the sigma factor of the RNA polymerase holoenzyme binds to the promoter region to form a(n)

Closed complex

The terminator is a ______.

DNA sequence that specifies the end of transcription

Transcription factors are proteins that bind to ______.

DNA sequences and control the rate of transcription

A gene is a DNA segment that is used to make a polypeptide only. True/False

False

For eukaryotic protein-encoding genes, the five proteins that are always needed for RNA polymerase II to initiate RNA synthesis are called

General transcription factors

Which of the following are self-splicing introns that occur in the rRNA genes of the protist Tetrahymena?

Group I introns

The association of a sigma factor with the core enzyme forms a complex referred to as the RNA polymerase

Holoenzyme

In eukaryotic protein-encoding genes, three categories of proteins are required for basal transcription at the core promoter: RNA polymerase ____, general transcription ____, and a complex called mediator.

II; factors

Who proposed the existence of messenger RNA in 1961?

Jacob and Monod

In eukaryotes, the protein complex called mediator facilitates the interaction between ______.

RNA polymerase II and regulatory transcription factors that bind to enhancers and silencers

Transcription is the process of synthesizing ______ from a(n) ______ template.

RNA;DNA

In E. coli, the transcription termination of certain genes requires an RNA-binding protein called

Rho factor

The core promoter typically consists of a TATAAA sequence called the ____ box and the transcriptional start site

TATA

The term closed complex refers to the ______.

The initial binding of the RNA polymerase holoenzyme to the promoter

An exonuclease binds to the 5' end of the RNA that is being transcribed and degrades it in the 5' to 3' direction. The exonuclease then catches up to RNA polymerase II and causes termination. This describes the ____ model of transcription termination in eukaryotes.

Torpedo

The synthesis of an RNA molecule from a DNA template is called

Transcription

Proteins that bind to DNA and control the rate of RNA synthesis are collectively called

Transcription factors

The first DNA base used as a template for RNA synthesis is called the

Transcription start site

For eukaryotic protein-encoding genes, what is the core promoter?

a relatively short DNA sequence that is necessary for transcription to take place

After RNA polymerase II transcribes the polyadenylation signal, it is destabilized and dissociates from the DNA. This describes the ____ model of transcription termination in eukaryotes.

allosteric

The phenomenon whereby different combinations of exons are joined to produce different mRNAs from the same transcript is called

alternative splicing

General transcription factors are those that are ______.

always needed for RNA pol II to initiate transcription

A ribozyme is a(n) ______.

an RNA with catalytic activity

For protein-encoding genes, the nontemplate strand is also called the

coding strand

What are snRNPs?

components of the spliceosome

In E. coli, the RNA polymerase holoenzyme is composed of the ______.

core enzyme plus sigma factor

In eukaryotic cells, the relatively short DNA sequence that is required for transcription to take place is known as the

core promoter

E. coli employs two different mechanisms for transcription termination: rho-____ and rho-_____ termination.

dependent; independent

An enzyme that cleaves a covalent bond between two adjacent nucleotides within a strand is called a(n)

endonuclease

Regulatory elements that stimulate transcription are termed

enhancers

What are the two types of regulatory elements that influence the rate of transcription in eukaryotes?

enhancers and silencers

Eukaryotic genes have two types of regulatory elements that influence the rate of transcription. These are called

enhancors and silencers

Coding sequences that are present in the mature mRNA are termed ______.

exons

Sequences in DNA that are present in mature mRNA and which code for polypeptides are called

exons

An enzyme that cleaves a covalent bond between two nucleotides at one end of a strand is called a(n)

exonuclease

A DNA segment that encodes a functional product, either an RNA molecule or a polypeptide, is termed a(n)

gene

The non-template strand is also called the coding strand because it ______.

has the same sequence as the mRNA but with thymine (T) instead of uracil (U)

The three stages of transcription are called

initiation, elongation, termination

Basal transcription refers to the low level of transcription that ______.

involves only the core promoter

François Jacob and Jacques Monod hypothesized the existence of which molecule?

mRNA

In eukaryotes, the interactions between RNA polymerase II and regulatory transcription factors that bind to enhancers and silencers are facilitated by a protein complex called

mediator

In eukaryotes, the assembly of ribosomal subunits occurs in a site within the nucleus called the

nucleolus

A structural gene encodes a(n) ______.

polypeptide

The first transcript produced from protein-encoding genes of eukaryotes is a long molecule called ____-mRNA.

pre

The DNA sequence that directs the exact location where transcription begins is called the

promoter

In a gene, the DNA is transcribed into RNA from the end of the ______.

promoter to the terminator

Structural genes are also known as ____ encoding genes.

protein

Enhancers are ______ that stimulate transcription.

regulatory elements in eukaryotes

The nucleolus in eukaryotes is the site of processing of ______.

ribosomal RNA

An RNA molecule that has catalytic activity is called a(n)

ribozyme

Splicing that does not require the aid of other catalysts is known as

self-splicing

The removal of introns where RNA functions as its own ribozyme is a process called ______.

self-splicing

Group I introns undergo a ______ process that is initiated by a(n) ______.

self-splicing ; free guanine outside the intron

The transition from the initiation to the elongation phase of bacterial transcription is marked by the release of the ______ ______ from the RNA polymerase holoenzyme.

sigma factor

Pre-mRNA splicing requires the aid of a complex called the

spliceosome

The base sequence of the RNA transcript is complementary to the

template strand of DNA

The strand of DNA that is transcribed into RNA is called the ______ strand, while the opposite strand of DNA is called the ______ strand.

template; coding

In bacteria, the rho factor is most important for ______.

termination of transcription

The DNA sequence that specifies the end of transcription is called the

terminator

Which of the following best defines a pre-mRNA?

the mRNA of eukaryotes that is produced in the nucleus and has yet to be processed

What marks the transition to the elongation stage of transcription in bacteria?

the release of the sigma factor from the RNA polymerase holoenzyme

The _______ is the first DNA base used as a template for RNA synthesis.

transcriptional start site

The +1 site in DNA typically designates the first base ______.

used as a template for RNA transcription

The formation of a stem-loop structure and the requirement for a helicase are characteristic of bacterial genes that undergo ____ _____ termination of transcription.

ρ-dependent