Process of Protein Synthesis

Question 1

process of transcription

Answer 1

• RNA polymerase binds to the promoter region
• DNA unwinds and becomes single-stranded
• RNA polymerase moves along template strand of DNA reading nucleotide sequence
• new nucleotides are added in a 5’ to 3’ direction
• transcription ends when RNA polymerase reaches the termination sequence

Question 2

process of RNA processing

Answer 2

• methyl-G cap added to 5’ end
• poly-A tail added to 3’ end
• introns are spliced out
• exons are spliced together via a spliceosome
• alternative splicing may occur, which is when exons are spliced out
• allows for a single gene to give rise to many different mRNA strands and code for many different proteins

Question 3

process of translation

Answer 3

• ribosome attaches to methyl cap
• reads until start codon (AUG) is recognised
• tRNA molecule with complementary anticodon binds to ribosome and adds amino acids
• next codon is matched with complementary anticodon
• new amino acid is added via condensation reaction
• stop codon signals end of translation
• polypeptide chain is released from ribosome into cytosol or ER