exam 3 part 2

Question 1

structural genes

Answer 1

encode proteins used in metabolism or play a structural role in the cell

Question 2

regulatory genes

Answer 2

encode products that interact with other sequences and affect transcription/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

rapid turn on/ off

Answer 4

ability to respond to sudden changes

Question 5

sequential gene expression

Answer 5

cascades of gene expression that turn on in order

Question 6

constitutive

Answer 6

always on

Question 7

positive control

Answer 7

regulatory protein (activator) binds to DNA to stimulate transcription

Question 8

negative control

Answer 8

regulatory protein (repressor) binds to DNA to prevent transcritpion

Question 9

inducible control

Answer 9

transcription is normally off and is turned on when a small molecule binds the regulatory protein

Question 10

repressible control

Answer 10

transcription is normally on and is turned off when a small molecule binds the regulatory protein

Question 11

operon

Answer 11

segment of DNA containing controlling regions and structural genes controlled by those regions

Question 12

regulatory gene

Answer 12

codes for repressor

Question 13

promotor

Answer 13

binds to RNA polymerase to allow transcription

Question 14

operator

Answer 14

interacts with repressor

Question 15

lacZ,Y,A

Answer 15

transcribed and translated into proteins

Question 16

lac Z

Answer 16

B-galactosidase

Question 17

lac Y

Answer 17

permease

Question 18

lac A

Answer 18

transacetylase

Question 19

polycistronic mRNA

Answer 19

produced during transcription

Question 20

cis acting

Answer 20

action of an element affects only the genes adjacent to it
- operator and promoter elements

Question 21

trans acting

Answer 21

diffusible product is produced. mutant doesn’t have to be adjacent
- repressor

Question 22

I+

Answer 22

normal repressor

Question 23

I-

Answer 23

repressor cannot bind to operator

Question 24

Is

Answer 24

stays stuck to operator meaning repressor cannot bind allolactose

Question 25

Oc

Answer 25

operator cannot bind to repressor

Question 26

P-

Answer 26

promoter cannot bind to RNA polymerase

Question 27

lacI-

Answer 27

constitutive always on

Question 28

lac Oc

Answer 28

constitutive always on

Question 29

I+ is ---- to I-

Answer 29

transdominant

Question 30

negative control

Answer 30

regulatory molecule binds to the DNA to turn genes OFF

Question 31

repressible system

Answer 31

repressor must interact with corepressor so the complex can bind to the DNA and turn the off the operon

Question 32

allosteric action

Answer 32

a change occurs in the conformation of the repressor when it binds to Trp

Question 33

feedback inhibition

Answer 33

excess trp in cell decreases the production of the enzymes used to make trp

Question 34

attenuator

Answer 34

located in the leader sequence and responsible for decreasing transcription when trp is present

Question 35

antisense RNA

Answer 35

small RNA molecules complementary to parts of the mRNA - base pair to mRNA and inhibit translation

Question 36

riboswitches

Answer 36

RNA sequences in the mRNA that affect the translation of that mRNA