regulating translation

Question 1

in eukaryotes and some prokaryotes, translation of the mRNA can be inhibited by which molecule ?

Answer 1

• RNA interference (RNAi)

Question 2

why is it called RNA interference ?

Answer 2

• when a mRNA molecule that has already been transcribed gets destroyed before it is translated to create a polypeptide chain

Question 3

what exact molecule causes the destruction of mRNA ?

Answer 3

small interfering RNA (siRNA)

Question 4

what happens at stage 1 on the diagram ? pg34

Answer 4

• an enzyme can cut the mRNA into siRNA

Question 5

what happens at stage 2 ?

Answer 5

• one strand of the siRNA then combines with another enzyme

Question 6

what do we call the siRNA combined with another enzyme ?

Answer 6

• siRNA - enzyme complex

Question 7

what will the siRNA - enzyme complex do ? 3

Answer 7

• it will bind via complementary base pairing to another mRNA molecule

Question 8

what will the enzyme do to the mRNA ? 4

Answer 8

• it will cut up the mRNA so it cannot be translated
• so turns the particular gene off and polypeptide chain is not made