Chapter 15: Gene Regulation Pt. 1

Question 1

how do bacteria respond to their environment?

Answer 1

metabolically

Question 2

what are the two types of gene expression?

Answer 2

inducible and constitutive enzymes

Question 3

what is an example of a repressible system?

Answer 3

tryptophan production in bacteria

Question 4

inducible or repressible systems are regulated under

Answer 4

positive or negative control

Question 5

negative control is present under a

Answer 5

repressible system (trp operon)

Question 6

positive control is present under an

Answer 6

inducible system (lac operon)

Question 7

what are the 3 structural genes of the lac Operon?

Answer 7

• lacZ
• lacY
• lacA

Question 8

lacZ gene encodes for

Answer 8

B-galactosidase

Question 9

B-galactosidase is an enzyme that converts lactose into

Answer 9

glucose and galactose

Question 10

lacY gene encodes for

Answer 10

permease

Question 11

permease facilitates entrance of

Answer 11

lactose into the bacteria cell

Question 12

lacA gene encodes for

Answer 12

transacetylase

Question 13

transacetylase is involved in the removal of…

Answer 13

toxic by-products from digestion of lactose

Question 14

what is a cistron?

Answer 14

part of a nucleotide sequence coding for a single gene

Question 15

structural genes of lac operon result in

Answer 15

polycistronic mRNA

Question 16

merozygotes are

Answer 16

cells that are diploid for certain genes

Question 17

CAP stands for

Answer 17

catabolite-activating protein

Question 18

two characteristics of CAP

Answer 18

• helps activate expression of lac operon

- able to inhibit expression in presence of glucose

Question 19

cAMP stands for

Answer 19

cyclic adenosine monophosphate

Question 20

attenuation occurs in

Answer 20

leader sequence that contains attenuator sequence

Question 21

antiterminator hairpin occurs in the absence of ______ between sections ______

Answer 21

tryptophan

2 and 3

Question 22

terminator hairpin occurs…

Answer 22

in the presence of tryptophan

3 and 4

Question 23

other forms of regulation involving RNA

Answer 23

• attenuation
• riboswitches
• small noncoding RNAs (sRNAs)