Explain how the Iodine Test is adapted to assay for Amylase

Explain how the Iodine Test is adapted to assay for Amylase Activity. Your response must include the following items in your explanation. These items do not represent a list of all the items needed in your response. Define %T and its role in the Amylase assay. The relationship between %T and Amylase concentration The relationship between the rate of %T change and Amylase activity

Solution

Also known as the starch amylase assay

The enzyme alpha-amylase, cleaves the internal alpha-1,4- glycosidic linkages present in starch, to produce either glucose, maltose, or dextrins, and glucoamylase. The enzyme cuts the alpha1,4- and 1,6-glycosidic linkages, to give glucose from the nonreducing ends of starch. Assays to determine the activity of alpha amylase and glucoamylase include decreased staining value of blue starch–iodine complexes, which is based on the formation of colour which occurs due to iodine that binds to starch polymers. This results in a blue black colour. The presence of the blue black colour is indicative of amylase activity.

%T - Also known as transmittance, which can be defined as the amount of light that is not being absorbed by a solution at that particular wavelength. As the reaction progresses , amylase will break down starch into glucose. Starch gives blue black colour with iodine but glucose does not. So, with the progression of the reaction, there is a decrease of the blue black colour , thus there is a decrease in the absorbance and increase in the transmittance of the same.