How is DNA transcribed into mRNA?

The gene to be transcribed s unwound and unzipped using the enzyme DNA helicase which breaks the hydrogen bonds between complementary bases. Activated RNA nucleotides then bind to the exposed complementry bases forming hydrogen bonds. RNA polymerase is used to make the sugar-phosphate backbone of the mRNA strand. The mRNA produced is complementary to the template strand of DNA therefore is a copy of the base sequence of the coding DNA strand. The mRNA strand is then released through the nuclear pore and travels to the ribosome, ready for translation. 

SJ

Related Biology A Level answers

All answers ▸

Glycogen and amylose are used for energy storage. Glycogen is found in animals. Amylose is found in plants. Describe how the structure of glycogen allows it to perform its function and explain the advantage to animals of using glycogen as an energy


What is an autoimmune disease?


Blue-spotted tree monitors (Varanus macraei) are found on the Indonesian island of Batanta. Describe how you could use the mark-release-recapture method to estimate the number of Varanus macraei on the island. (4 marks)


Describe the structure of proteins