What substance does amylase, used in presumptive testing, react with?

Amylase is an enzyme primarily involved in the breakdown of starch into sugars. It specifically reacts with starch during presumptive tests to indicate the presence of this polysaccharide. In a crime scene investigation, the detection of amylase can help identify biological fluids, particularly saliva, since saliva contains high levels of this enzyme.

In the context of this question, the interaction of amylase with starch is significant in forensic analyses, especially in cases where saliva might be present at a crime scene. It allows investigators to target biological substances of interest that could hold evidential value.

Other substances mentioned, such as sugars, amino acids, and proteins, are not the primary substrates for amylase. Sugars are the end products of starch breakdown and do not provide a direct interaction during the initial presumptive testing that involves amylase. While amylase can indirectly relate to sugars, its function is not to react with them but to break down starch into those simpler forms.