Describe the stages in DNA transcription and translation

DNA is unziped by DNA helicase. RNA polymerase catalyses the formation of a complementary strand of pre-mRNA, using the non-coding strand of DNA as a template. The pre-mRNA contains non-coding regions (introns) which are removed through splicing to form mature-mRNA. As the mRNA is single stranded, it can leave the nucleus via the nuclear pores and bind to a ribosome on the rough endoplasmic retIculum (rER). Starting with the 'start' codon, each codon on the mRNA sequence is read in order. The amino acid which corresponds with each codon is carried by a tRNA to the ribosome. Adjacent amino acids form peptide bonds which results in the formation of a long chain of amino acids, or a polypeptide.

IN

Related Biology A Level answers

All answers ▸

When a nerve impulse arrives at a synapse, it causes the release of neurotransmitter from vesicles in the presynaptic knob. Describe how.


What is co-transport and why do I sometimes hear it being called active transport?


Describe the structure of proteins


Describe the Benedict's test for reducing sugars and how this can be modified to test for non-reducing sugars