Gene regulation

Question 1

why do we need gene reg?

Answer 1

all genes in every cell are the same and some need to be turned off

Question 2

advantages of gene reg?

Answer 2

save energy and resources

Question 3

operon model

Answer 3

multiple genes involved in same process together and an operator sequence

Question 4

operator sequence

Answer 4

the “switch” to turn on/off genes

Question 5

repressor proteins

Answer 5

binds to operator sequence to stop transcription by stopping RNA poly from getting to promoter

Question 6

inducers

Answer 6

• attaches to repressor proteins either causing them to bind or fall of from the operator sequence

Question 7

Lac operon

Answer 7

• high lactose in cell
• lactose = inducer to repressor protein -> binds to repressor protein
• protein falls of operator sequence and operon to create lactose digesting proteins is turned on again.
• lactose digested and no lactose left.
• lactose used up on repressors
• repressors go back to operators and stop enzyme production

Question 8

TRP operon

Answer 8

• high tryptophan means high bonding of repressor so low production of trp (p FBL)
• low trp means less repression means more trp made