Transcription

Question 1

What is protein synthesis?

Answer 1

The process which produces proteins from the information in the DNA code.

Question 2

What is Transcription?

Answer 2

The DNA code is copied into a single strand called messenger RNA.

Question 3

Where does it take place?

Answer 3

In the nucleus

Question 4

Why is it necessary?

Answer 4

The DNA molecule is large so it cannot get through the nuclear pores so smaller mRNA is used to copy a section of DNA which codes for a protein. The mRNA leaves the nucleus and joins a ribosome where the protein is synthesised.

Question 5

What is 1st stage of Transcription?

Answer 5

RNA polymerase binds at the start codon and DNA helicase binds which breaks the hydrogen bonds on a section of DNA that contains the gene for the desired protein. Bases are exposed.

Question 6

What is the 2nd stage of Transcription?

Answer 6

RNA polymerase moves along the template strand and joins free nucleotides that are complementary to the exposed template strand to form a pre-mRNA.

Question 7

What is the 3rd stage of Transcription?

Answer 7

DNA bases rejoin behind the RNA polymerase and it will stop and detach when it reaches the stop codon. Pre-mRNA will be spliced before leaving the nuclear pore.

Question 8

What are exons and introns?

Answer 8

Exons are regions that code for proteins whereas introns dont.

Question 9

What is splicing?

Answer 9

Removing introns in pre-mRNA (only happens in eukaryotes)