3.8 Transcription and translation

Question 1

Transcription

Answer 1

• DNA helicase breaks H bonds between complementary base pairs in DNA leaving exposed bases
• 1 DNA strand acts as a template
• (free floating RNA nucleotides bind to exposed bases with complementary base pairing (adenine and uracil, cytosine and guanine)
• RNA polymerase joins nucleotides together by phosphodiester bonds, making pre mRNA
• Introns spliced out forming mRNA

Question 2

Translation

Answer 2

• mRNA attatches to a ribosome
• A tRNA with a complementary anticodon binds to the mRNA codon
• tRNA brings a specific amino acid
• 2 tRNA’s bind simultaneously
• Amino acids form a peptide bond via condensation reaction
• First tRNA detaches, ribosome moves to next codon
• Ribosome detaches at stop codon