Final answer:
Nirenberg and Matthaei's experiments demonstrated that synthetic mRNA with a single type of nucleotide resulted in single-amino-acid polymers, showing that enzymes do not specify protein sequences. The complexity of protein structures requires a precise sequence of nucleotides in DNA, with each gene coding for a specific polypeptide.
Step-by-step explanation:
The discovery that enzymes cannot specify the order of non-repetitive heteropolymers (proteins) is based on genetic information flow studies, particularly those related to mRNA and protein synthesis. Nirenberg and Matthaei's experiments in 1961 revealed that synthetic mRNA with repeating nucleotides resulted in the production of polymers with a single repeating amino acid, such as uracil leading to phenylalanine chains. However, the complexity of actual proteins could not be accounted for by this simple relationship, pointing to the need for a diverse and specified sequence encoded by DNA to yield the variety of proteins found in living organisms. More extensive studies involving different nucleotides and the one gene-one polypeptide hypothesis further clarified the role of genes in determining protein structure and function, firmly establishing that enzymes, although highly specific in their actions, do not dictate the primary sequence of a protein. This understanding is critical for the development of pharmaceutical applications, such as the design of enzyme-sensitive hybrid polymers and the crafting of drug delivery systems.