SPEC POINT 2.8

Question 1

Explain how the sequence of bases in DNA ensures the correct order of amino acids in a polypeptide chain:

Answer 1

1. the sequence of bases in a gene is transcribed to produce mRNA 2. the sequence of triplets in DNA determines the sequence of codons in mRNA (due to complementary base paring)
2. the mRNA is translated to form the polypeptide chain, according to the genetic code the sequence of codons determines the sequence of amino acids in a polypeptide chain (primary structure).
3. therefore, the sequence of bases in a gene, determines what the primary structure of a protein will be