8.4: Protein Synthesis, transcription+splicing

Question 1

Transcription

Answer 1

Process of making pre-mRNA using part of the DNA as a template

Question 2

How are nucleotide bases exposed

step 1

Answer 2

An enzyme acts on the specific region of the DNA causing the two strands to separate = nucelotide bases exposed

Question 3

Template strand

step 2

Answer 3

(The nucleotide bases on one of the two DNA strands)

pair with complementory nucleotides from the pool in the nucleus

Question 4

Role of RNA polymerase

step 3

Answer 4

joins the nucleotides together - pre mRNA molecule

Question 5

pre-mRNA

step 4

Answer 5

as pre-mRNA strand is made

the DNA rejoins behind it

Question 6

stop triplet code

step 5

Answer 6

When the RNA polymerase reaches the stop triplet code, it detaches = pre mRNA complete

Question 7

Splicing

of pre-mRNA

Answer 7

the removal of intervening introns and the joining exons
= mRNA
mRNA molecules leave through nuclear pores

Question 8

Exons

Answer 8

code for protein

useful

Question 9

Introns

Answer 9

prevent synthesis of a polypeptide and intervene

not useful

Question 10

No splicing occurs in …

why

Answer 10

prokaryotes as there are no introns in prokaryotic DNA