6.10

Question 1

Describe the process of transcription including post transcriptional changes

Answer 1

Transcription occurs in the nucleus
DNA helicase unwinds and unzips DNA by breaking hydrogen bonds between the strands
Free RNA nucleotides join to exposed DNA template strand and phosphodiester bonds form between adjacent RNA nucleotides
This forms strand of RNA made of introns and exons.
Splicing then occurs which is a form of post transcriptional change where introns are removed and exons are left

Question 2

Explain how post transcriptional modifications of mRNA enable this number of proteins to be produced

Answer 2

Alternative splicing occurs after transcription where exons are selected and ordered randomly.
Due to this, it results in changes to the amino acid sequence (primary structure) of the protein, further effecting R group interactions and folding
This results in proteins having different functions