Neonatal diabetes is a disease that affects newly born children - AQA - A-Level Biology - Question 5 - 2021 - Paper 2

The alteration in the amino acid sequence of insulin leads to a change in its tertiary structure. As a result, the modified insulin molecule cannot fit properly into the binding site of the insulin receptor due to loss of molecular complementarity. Typically, the specific shape and charge of insulin ensure that it can effectively bind to its receptor; however, in this case, the structural change disrupts this interaction.