Final answer:
To detect contaminating amylase in buffers or cellulose, a control tube is used. This compares to enzyme-added tubes to check for unwanted enzymatic activity. The iodine test can confirm amylase activity by the color change due to amylose binding.
Step-by-step explanation:
When performing experiments that involve the enzymatic digestion of polysaccharides like amylose and glycogen, it is critical to ensure that there is no contamination by enzymes like amylase that may already be present in the buffer or cellulose preparations. Amylase is the enzyme responsible for catalyzing the breakdown of these polysaccharides into simpler sugars like glucose and maltose during digestion, both in the mouth (salivary amylase) and the small intestine (pancreatic amylase).
To detect contaminating amylase, a control tube that contains all the components of the experiment except for the introduced enzyme (cellulase, in this context) is used. If there is amylase activity in the control tube, it would suggest the presence of contaminating amylase in the buffer or cellulose. By comparing the results with tubes that have the added enzyme, it's possible to determine if there is any unwanted enzymatic activity that could affect the results of the experiment.
Tests for amylase contamination may involve colorimetric assays, such as the iodine test for starch breakdown products, since iodine binds to amylose, a component of starch, producing a blue-violet color. This can indicate whether amylase has acted on the starch components present and thus is indicative of contamination. Ensuring the absence of contaminating amylase is crucial for the validity of such biochemical experiments.