Control of Gene Expression in Eukaryotes

Question 1

Differential Gene Expression

Answer 1

Responsible for forming specialized cells types, arranging the into tissues, and coordinating their activity in the multicellular society that is the individual.

Question 2

Chromatin

Answer 2

DNA wrapped around proteins.
Has profound implications for the control of gene expression.
Must be condensed to expose the promoter so RNA polymerase can bind to it.

Question 3

Chromatin Remodeling

Answer 3

Process by which the structure of chromatin is changed to allow or inhibit transcription or replication.

Question 4

RNA Processing

Answer 4

Steps required to produce a mature, processed mRNA from a primary RNA transcript.

Question 5

Histones

Answer 5

DNA associated proteins.
H1 “seals” DNA to each nucleosome; interact with one another to create tightly packed structures.
Positively charged.

Question 6

Nucleosome

Answer 6

A bead-like unit of eukaryotic chromatin.

Question 7

DNases

Answer 7

Enzymes that cut DNA.

Question 8

Histone Code

Answer 8

Particular combinations of histone modification set the stat of chromatin condensation for a particular gene.

Question 9

Histone Acetyltansferases (HAT)

Answer 9

ADD acetyl groups to the positively charged lysin residues in histones.
Creates a binding site for other proteins that help open chromatin.
On switch

Question 10

Histone Deacetylases (HDAC)

Answer 10

REMOVE acetyl groups from histones and lead to condensed chromatin.
Off switch

Question 11

Chromatin-Remodeling Complexes

Answer 11

Group of proteins that use energy from ATP hydrolysis to shift nucleosomes on DNA.

Question 12

Epigenetic Inheritance

Answer 12

Any mechanism of inheritance that is due to something other than differences in DNA sequences.

Question 13

Regulatory Sequences

Answer 13

Serve as a binding site for other proteins needed to start transcription.

Question 14

Core Promoter

Answer 14

Used to indicate the specific sequence where RNA polymerase bind.

Question 15

TATA-Binding Protein (TBP)

Answer 15

A protein the binds to the TATA box in eukaryotic promoters and is a component of the basal transcription complex.
TATA Box is a core promoter.

Question 16

Promoter-Proximal Elements

Answer 16

Have sequences that are unique to specific sets of genes.

Positive control

Question 17

Introns

Answer 17

Transcribed sequences that are spliced our of the primary transcript.

Question 18

Exons

Answer 18

Transcribed regions that are included in the mature RNA on splicing is complete.

Question 19

Enhancers

Answer 19

Regulatory sequences that are far from the promoter and activate transcription.
Many types, most genes have more than one, have different binding sites.

Question 20

Activators

Answer 20

Bind to enhancers and begin transcription.

Bring chromatin-remodeling proteins to the right place at the right time.

Question 21

Silencers

Answer 21

Work to inhibit transcription.

Question 22

Repressors

Answer 22

Bind to silencers and shut down transcription.

Question 23

Regulatory Transcription Factors

Answer 23

Protein that binds to a DNA regulatory sequence to influence transcription. (Regulatory and general factors)
*Different types of cells express different genes because they have different factors.

Question 24

Affinity

Answer 24

The strength of a protein’s binding to a target.

Question 25

General Transcription Factors

Answer 25

Proteins that interact with the core promoter and are not restricted to particular genes or cell types.
i.e. TATA-binding protein

Question 26

Mediator

Answer 26

Acts as a bridge between regulatory transcription factors, general transcription factors and RNA polymerase II.

Question 27

Transcriptional Activators

Answer 27

Bind to regulatory sequences of particular genes to recruit proteins needed to remodel chromatin.

Question 28

Alternative Splicing

Answer 28

Splicing the same primary RNA transcript in different ways.
Controlled by proteins that bind to RNA’s in the nucleus and interact with spliceosomes.
In control of gene expression in multicellular eukaryotes.

Question 29

Gene

Answer 29

nucleotide sequence that allows the production of one or more related RNAs or polypeptides.

Question 30

RNA Interference (RNAi)

Answer 30

Occurs when a small, single-stranded RNA held by a protein complex binds to a complementary sequence in mRNA.
Either leads to destruction of the mRNA or blocks the mRNA translation.

Question 31

Proteasome

Answer 31

Recognizes proteins that have a ubiquitin tag and cuts the into short segments.

Question 32

DNA Packaging

Answer 32

Decondensed for general and regulatory transcription factors to gain access to genes and fro RNA polymerase to initiate transcription.