Chapter 12

Question 1

structural genes

Answer 1

encoding proteins

Question 2

regulatory genes

Answer 2

encoding products that interact with other sequences and affect the transcription and translation of these sequences

Question 3

regulatory elements

Answer 3

DNA sequences that are not transcribed but play a role in regulating other nucleotide sequences

Question 4

constitutive expression

Answer 4

continuously expressed under normal cellular conditions

Question 5

positive control

Answer 5

stimulates gene expression

Question 6

negative control

Answer 6

inhibits gene expression

Question 7

inducible operon

Answer 7

transcription is usually off and needs to be turned on

Question 8

repressible operons

Answer 8

transcription is normally on and needs to be turned off

Question 9

negative inducible operons

Answer 9

operons that are usually off and need to be turned on, so the transcription is inducible

Question 10

inducer

Answer 10

small molecule that turns on the transcription

Question 11

negative repressible operon

Answer 11

transcription is usually on and needs to be turned off, so the transcription is repressible

Question 12

corepressor

Answer 12

a small molecule that binds to the repressor and makes it capable of binding to the operator to turn off transcription

Question 13

positive inducible operon

Answer 13

operons that are usually off and need to be turned on, so the transcription is inducible

Question 14

positive repressible operon

Answer 14

transcription is usually on and needs to be turned off, so the transcription is repressible

Question 15

lacI

Answer 15

repressor encoding gene

Question 16

lacP

Answer 16

operon promoter

Question 17

lacO

Answer 17

operon operator

Question 18

lacZ

Answer 18

encoding beta-galactosidases

Question 19

lacY

Answer 19

encoding permease

Question 20

lacA

Answer 20

encoding transacetylase

Question 21

cis-acting mutation

Answer 21

able to control the expression of genes only when on the same piece of DNA

Question 22

trans-acting mutation

Answer 22

able to control the expression of genes on other DNA molecules

Question 23

structural-gene mutations

Answer 23

affect the structure of the enzymes, but not the regulations of their synthesis

Question 24

regulator gene mutations

Answer 24

affect the regulation of protein production

Question 25

catabolite repression

Answer 25

using glucose when available and repressing the metabolite of other sugars

Question 26

activator proteins

Answer 26

stimulate and stabilize basal transcription apparatus by binding regulator sequences like enhancers

Question 27

insulator

Answer 27

DNA sequence that blocks or insulates the effect of enhancers

Question 28

repressors

Answer 28

bind regulatory sequences on promoter or distant sequences to inhibit transcription

Question 29

DNA methylation

Answer 29

addition of methyl groups to nucleotide bases

Question 30

histone modifications

Answer 30

more than 100 different post-translational modification of histone proteins