biochap11

What are two major benefits of gene regulation?

- the conservation of energy - expression of genes at appropriate times

At the level of transcription, there are several common factors that contribute to combinatorial control. What are they?

1. One or more repressor proteins may be involved in transcriptional regulation2. One or more activator proteins may be involved in transcriptional regulation3. DNA methylation usually inhibits transcription

Select the two ways that a repressor can interact with a GTF to inhibit transcription.

A repressor can inhibit assembly of the pre-initiation complex. A repressor can prevent binding of TFIID to the TATA box.

Which of the following statements about histone acetylation is TRUE?

Acetylated histone proteins do not bind as tightly to the DNA, which aids in transcription.

Which of the following is a form of gene regulation in which a eukaryotic pre-mRNA can be processed to produce more than one mature RNA?

Alternative splicing

What is the advantage of operon organization in bacteria?

Bacteria can coordinate the expression of multiple genes in the same biological pathway.

The core promoter of a eukaryotic gene typically includes the box and the start site.

Blank 1: TATA Blank 2: transcriptional

Small effector molecules bind to regulatory factors and cause conformational changes that influence their ability to bind to DNA. Listen to the complete question

Blank 1: transcription

An activator protein recognizes the ______ of the lac operon.

CAP site

What is the CAP site for the lac operon?

The sequence of nucleotides that is recognized by an activator protein

When binds to CAP, the resulting complex binds to the CAP site near the lac . This causes a bend in the DNA that enhances the ability of RNA polymerase to bind, and so the transcription rate is increased.

cAMP; promoter

During transcription, evicted histones are then reassembled by _______ proteins and placed back on the DNA behind the moving RNA polymerase II. These histones may be _______ so they bind more tightly to the DNA.

chaperone; deacetylated

Different cell types, such as skin cells and nerve cells, have different morphologies because are expressed and regulated in different ways in different cells.

genes

Most in all species are regulated so the proteins they specify are produced at appropriate times and in specific amounts.

genes

The process whereby different transcripts are made from a single gene is called

Blank 1: alternative Blank 2: splicing

The binding of general transcription factors and RNA polymerase II to the core promoter is facilitated by the actions of -remodeling complexes and -modifying enzymes. This allows the formation of a preinitiation complex.

Blank 1: chromatin Blank 2: histone

Proteins that use energy from ATP hydrolysis to change the locations and compositions of nucleosomes are called ATP-dependent - complexes.

Blank 1: chromatin Blank 2: remodeling

Repressors are regulatory transcription that bind to the DNA and decrease the rate of transcription. This is a form of regulation called control. On the other hand, bind to the DNA and increase the rate of transcription, a form of regulation termed control.

Blank 1: factors Blank 2: negative Blank 3: activators Blank 4: positive

Many eukaryotic genes are flanked by a nucleosome- , which is a site that is missing nucleosomes.

Blank 1: free Blank 2: region

The protein IRP binds to a site within the ferritin mRNA known as the (IRE).

Blank 1: iron Blank 2: regulatory Blank 3: element

Which of the following is an example of developmental gene regulation in mammals?

Different globin genes are expressed in the embryo, fetus, and adult.

True or false: Methylation of DNA near the promoter a eukaryotic gene activates transcription of the gene.

False

What is the function of general transcription factors (GTFs) in the initiation of transcription?

GTFs and RNA polymerase come together at the core promoter for the initiation of transcription.

When the IRP is bound to ______, translation is blocked; when the IRP is bound to ______, translation proceeds.

IRE; iron

Which of the following factors help to increase transcription levels in eukaryotes?

Loosening of chromatin structure Binding of an activator protein to DNA

What are small effector molecules

Molecules that bind to transcription factors and change their conformation

Control of gene expression takes place at what levels in eukaryotes? Select all that apply.

Post-translation Transcription Processing of mRNA Translation

What are regulatory transcription factors?

Proteins that bind to DNA and affect the transcription of one or more genes

How can gene regulation conserve energy?

Proteins that metabolize molecules such as small sugars are produced only when those sugars are available in the environment.

Living organisms benefit from gene regulation because it conserves energy; that are encoded by genes will be produced only when they are .

Proteins; necessary

An activator can improve the ability of ______ to bind to the TATA box on the DNA.

TFIID

What is the role of the TATA box?

The TATA box determines the starting point of transcription.

Which of the following describe the TATA box?

The TATA box is a sequence upstream of the transcriptional start site. The TATA box determines the precise starting point for transcription.

What is the function of chromatin-remodeling complexes?

They cause a change in the locations and/or compositions of nucleosomes

At what levels does gene regulation occur in prokaryotes?

Transcription Translation Post-translation

Matching

Transcription matches , Control of synthesis of mRNA from a gene Control of synthesis of mRNA from a gene RNA processing matches , Regulation of splicing of mRNA Regulation of splicing of mRNA Translation matches Regulation of protein synthesis Post-translation matches Choice, Regulation of the amount or function of a protein that has already been synthesized Regulation of the amount or function of a protein that has already been synthesized

How do CAP and cAMP increase the transcription of the lac operon?

When CAP and cAMP bind to the CAP site, this enhances binding of RNA polymerase to the promoter site

How does the presence of lactose in the cell influence the transcription of the lac operon?

When lactose is present, transcription of the lac operon is high. When lactose is present, the lac repressor protein does not bind to the operator site and transcription can occur.

A nucleosome-free region (NFR) is

a site on a chromosome that is missing nucleosomes

When iron levels are low, the iron regulatory protein:

binds to the iron regulatory element and blocks translation of ferritin

Operons enable bacteria to

coordinate the regulation of genes with related functions

In eukaryotes, DNA methylation usually gene transcription.

decreases

During mammalian development

different globin genes are expressed at different developmental stages

Which of the following elements are DNA sequences that regulate gene transcription? Select all that apply.

enhancers silencers

The morphologies of different cell types, such as skin cells and nerve cells, is strikingly different. This is due to the fact that the cells:

express different genes

The process in which the information in a gene is made into a functional gene product, such as an RNA molecule or a protein, is termed gene .

expression

A(n) is a cluster of genes that are part of a single transcription unit that is under the control of a single promoter.

operon

The catabolite activator protein (CAP) is involved in ______ control of the lac operon.

positive

What are the basic components of the lac operon?

promoter lacZ lacY lacA

An activator can affect the function of a GTF by

recruiting the GTF to the TATA box

Regulation of prokaryotic gene expression typically involves all of the following mechanisms except

regulation of RNA processing

The lac repressor protein prevents the enzyme RNABlank 1 RNA polymerase 2 polymerase from transcribing the genes in the lac operon.

Blank 1: RNA Blank 2: polymerase

Under what conditions does the lac repressor bind to the operator of the lac operon and prevent transcription?

When the concentration of lactose is low in the cell

The production of the functional product of a gene is called

gene expression.

In order to initiate transcription, RNA polymerase II must associate with proteins known as ______ transcription factors at the TATA box of the core promoter. Multiple choice question. ubiquitous

general

The acetylation of proteins can loosen chromatin packing.

histone

In eukaryotes, DNA methylation usually gene d transcription.

inhibits

The mRNA encoding ferritin is controlled by an RNA-binding protein called the

iron regulatory protein

In the lac operon, the _______ is the DNA sequence at which the lac repressor binds.

operator

The lacO site of the lac operon is called the and is the site where the repressor protein binds.

operator

The transcription of the lac operon genes is inhibited when the lac repressor protein binds to

the lac operator