Question

3. What are some issues with using data from the spectrophotometry lab to estimate the concentration of maltose and amylase found in saliva? 4. If the issues that you've outlined above make you wary of your results, how would you set this experiment up differently?

Answer 1

3. Many spectrophotometric methods are based on amylase which breaks down starch in the saliva producing the end product maltose,this maltose acts on various compounds to  release reducing groups which are evaluated colorimetrically and the results reflect the amount of amylase present in the saliva. The issues of using this method is that the sensitivity of some maltose reducing agents is very low, in some cases the reduction is interuppted by the presence of calcium ions present in most of the amylase preparations. Apart from these, the sensitivity of the test iis limited to endo acting amylases and less of exo acting amylases. So the result may not directly point out to the actual quantification of amylase.

4. To overcome the above issues, an alternative to colorimetry or spectrophotometer would be to use titration methods like Shaffer Somogyi method. Here the maltose produced by amylase action on starch is evaluted against a maltose standard curve. Here the reducing sugars are treated with alkaine copper solutions and the resulting reduced copper is reacted with tsodium hiosulphate. The difference between blank and maltose concentrations are plotted against the standard curve.