Chapter 15: Eukaryotic Gene Expression

Question 1

what is known as the hallmark of cancer?

Answer 1

uncontrolled proliferation

Question 2

activation and repression of gene expression is a

Answer 2

delicate balancing act for an organism

Question 3

regulation of gene expression in bacteria is linked to

Answer 3

metabolic need

Question 4

in eukaryotes regulation of gene expression has several

Answer 4

levels of regulation

Question 5

what forms chromatin?

Answer 5

histone and nonhistone proteins

Question 6

nucleosomes are

Answer 6

repeating DNA-histone complexes

Question 7

compact chromatin inhibits which processes?

Answer 7

• DNA replication
• DNA repair
• transcription

Question 8

what is known as a space that is occupied by an individual chromosome?

Answer 8

discrete domain

Question 9

what is known as channels between chromosomes that contain little to no DNA?

Answer 9

interchromatin compartments

Question 10

transcriptionally active genes are located…

Answer 10

at the edge of chromosome territories next to channels

Question 11

where is RNA processing machinery found?

Answer 11

in the interchromatin compartments

Question 12

chromosome alterations include…

Answer 12

• chromatin conformation

- histone modification

Question 13

an example of chromosomal conformations is

Answer 13

H2A to H2AZ

Question 14

examples of histone modifications include

Answer 14

-covalent bonding
-acetylation
-

Question 15

acetylation decreases…

Answer 15

the positive charge of histones

Question 16

Histone acetyltransferase enzymes (HATs)

Answer 16

• catalyze histone acetylation

- are associated with increased transcription

Question 17

histone deacetylases (HDACs)

Answer 17

• remove acetyl groups from histone tails

- recruited to genes by transcription repressor proteins

Question 18

examples of chromatin alterations include…

Answer 18

• histone modification
• DNA methylation
• chromatin remodeling

Question 19

chromatin remodeling involves

Answer 19

repositioning or removal of nucleosomes on DNA

Question 20

DNA methylation plays a role in gene expression by

Answer 20

repressing gene expression

Question 21

what are the two types of promoters?

Answer 21

1. focused core promoters

2. dispersed core promoters

Question 22

list five core promoter elements

Answer 22

1. initiator element
2. TATA box
3. TFIIB recognition element (BRE)
4. motif ten element (MTE)
5. downstream promoter element (DPE)

Question 23

transcription factors serve to

Answer 23

increase or reduce levels of transcription

Question 24

what is an example of a gene that can be regulated due to the interplay of promoters, enhancer elements, and transcription factors?

Answer 24

Metallothionein 2A gene (MT2A)

Question 25

MT2A gene product is a

Answer 25

protein that binds to heavy metals and protects cells from toxic effects

Question 26

what initiates the formation of the pre-initiation complex (PIC)?

Answer 26

IID protein binding to TATA box

Question 27

define coactivators...

Answer 27

serve as bridge between activators and GeneralTranscriptionFactors

Question 28

define enhanceosomes...

Answer 28

large complexes of activators and coactivators that direct transcription activation

Question 29

exons

Answer 29

code for amino acids

Question 30

introns

Answer 30

do NOT code for amino acids

Question 31

variants of a protein are known as

Answer 31

isoforms

Question 32

what are the 5 different ways pre-mRNAs can be spliced?

Answer 32

1. cassette exons 2. alternative splice site 3. intron retention 4. alternative promoters 5. alternative polyadenylation

Question 33

what is the most common type of alternative splicing in plants, fungi and single celled eukaryotes?

Answer 33

intron retention

Question 34

transcription of what signal terminates transcription?

Answer 34

polyadenylation

Question 35

alternative splicing increases...

Answer 35

number of proteins made from each gene

Question 36

term that defines when the number of proteins an organism makes exceeds the number of genes in a genome

Answer 36

proteome

Question 37

RNA-binding proteins act by

Answer 37

binding or hiding splice sites to promote use of alternative sites

Question 38

term used for genetic disorders that are caused by mutations that disrupt RNA splicing

Answer 38

spliceopathies

Question 39

what is an example of a spliceopathy?

Answer 39

myotonic dystrophy

Question 40

what is known as the total amount of mRNA that a cell has for translation?

Answer 40

steady-state level of mRNA

Question 41

exoribonucleases are

Answer 41

enzymes that degrade RNA by removal of terminal nucleotides

Question 42

what are the enzymes that degrade the poly-A tail?

Answer 42

deadenylase

Question 43

exosome complex destroys mRNA in a

Answer 43

3' to 5' manner

Question 44

decapping enzymes

Answer 44

remove 5' cap

Question 45

XRN1 exoribonuclease destroys mRNA in a

Answer 45

5' to 3' manner

Question 46

mRNAs are cleaved internally by

Answer 46

endoribonucleases

Question 47

sncRNAs have two subtypes which are

Answer 47

siRNAs and miRNAs

Question 48

siRNAs...

Answer 48

cleave mRNA

Question 49

miRNAs...

Answer 49

inhibit translation

Question 50

RNAi is a mechanism by which

Answer 50

ncRNAs guide post-transcriptional silencing

Question 51

kinases are

Answer 51

enzymes that catalyze the addition of phosphate groups

Question 52

phosphatases are

Answer 52

enzymes that remove phosphates

Question 53

protein degradation regulation is done via

Answer 53

ubiquitin-mediated protein degradation

Question 54

proteasome

Answer 54

unwinds and removes ubiquitin tags