8.4: Protein Synthesis - Transcription

Question 1

What is the process of transcription

Answer 1

1. DNA helicase acts on a specific region of the DNA causing the two strands to separate and expose the nucleotide bases in that region
2. The nucleotide bases on one of the two DNA strands, known as the template strand, pair with their complementary nucleotides from the pool inside the nucleus. RNA polymerase moves along the strand and joins the nucleotides together forming pre-mRNA
3. When the RNA polymerase reaches a particular sequence of bases on the DNA that it recognises at a ‘stop’ triplet code, it detached, and the production of pre-mRNA is complete

Question 2

What is splicing

Answer 2

Splicing is when the INTRONS are removed from pre-mRNA - forming mRNA

Question 3

In what organism does splicing only occur

Answer 3

Eukaryotic organisms, prokaryotic cells do not have introns

Question 4

Where does the mRNA molecules go following transcription

Answer 4

They leave out of a nuclear pore, and are then attracted to the ribosomes to which it becomes attached