Chapter 18-19 - Regulating Gene Expression

Question 1

Dna on euk chromosomes are packaged into very compact dna-protein complexes called _______.

Answer 1

Chromatin

Question 2

In chromatin, DNA is wound around eight protein molecs called _________. It looks like beads on string.

Answer 2

Histones

Question 3

Each “bead” is called a…

Answer 3

Nucleosome

Question 4

Chromosmes have regions of loosely coiled chromatin called _________ and tightly packed chromatin called __________.

Answer 4

Euchromatin

Heterochromatin

Question 5

T or F - Heterochromatin is transcriptionally active

Answer 5

False - Euchromatin is active, heterochroamtin is like storage.

Question 6

Acetylation ________ transcription

Answer 6

Initiates

Question 7

Methylation _________ transcription.

Answer 7

Reduces

Question 8

What occurs in histone acetylation

Answer 8

Acetyl groups are attached to + charge lysines in histone tails, which loosen chromatins and promoting transcrip.

Question 9

How does DNA methylation work?

Answer 9

Methyl groups bind to certain bases in DNA, coiling the DNA tighter to reduce transcrip

Question 10

Regulatory sequences - Euk or Pro? What are they and what do they do?

Answer 10

Euk and Pro

Segments of noncoding DNA that help regulate transcription by binding to specific proteins

Question 11

What are regulatory seqs in pro? In euk?

Answer 11

Operators

Enhancers

Question 12

Enhancers bind to ______, which stimulate the ____________ of a gene.

Answer 12

Activator proteins

Transcription

Question 13

Euk promoters contain a common core sequence called a __________.

Answer 13

TATA Box

Question 14

TATA Box

Answer 14

A seq of dna rich in adenine and thymine

Question 15

To attach to RNA polymerase, Euk promoters bind with regularory proteins called ____________.

Answer 15

Transcription proteins

Question 16

General transcription factors

Answer 16

Essential for the transcription of all protein-coding genes

Question 17

Specific transcription factors

Answer 17

Needed for transcribing specific genes

Question 18

T or F - Specific transcrip factors can only be activators

Answer 18

False, both

Question 19

Activators bind to ________ regulatory sequences.

Answer 19

Enchancer

Question 20

Repressors bind to ______ regulatory sequences

Answer 20

Silencers

Question 21

A particular combo of regulatory sequences can activate transcription only when the ______________________ are present

Answer 21

appropriate activator proteins

Question 22

T or F - Even genes that do not work together still have same transcription fators

Answer 22

False - genes must work together

Question 23

What determines gene expression?

Answer 23

Transcription

Alternative RNA splicing

RNA Interference

Question 24

Diff mRNA’s can be made from one gene by splicing together different combos of introns.

Answer 24

Alternative RNA Splicing

Question 25

_______ inhibits mRNA, causing mRNA to degrade and inhibiting translation.

Answer 25

miRNA

Question 26

What happens to the lac operon when glucose is gone and lactose is present?

Answer 26

Allolactose inactivates active RP

HIGH CAMP, binds w/ CAP site

OperON

Abundant lac mRNA transcription

Question 27

What happens to the lac operon when both glucose and lactose is present?

Answer 27

Active RP is insctivated by allolactose

CAP doesnt go to cap site

OperON

LITTLE lac mRNA transcription

Question 28

What does the CAP site do in the lac operon?

Answer 28

Promotes DNA polymerase binding

Question 29

Where does the repressor bind? What happens when it does?

Answer 29

Operator

Blocks DNA polymerase

Question 30

What does tryptophan do in a bacterium’s environment? (How does it effect the prokaryote?)

Answer 30

Turns off the operon

Question 31

Is trp operon repressible or indicible?

Answer 31

Repressible

Question 32

What is an example lf an activator protein?

Answer 32

Catabolite Activator Protein (CAP)

Question 33

cAMP lvls ________ when glucose resources are low, which activates ____.

Answer 33

Increase

CAP

Question 34

When glucose increase, CAP _____ from the lac operon, ______ transcription

Answer 34

Detaches

Decreasing