Amylose - Amylase Lab
Takeaway
Enzymes are molecules in living things that have the job of chemically changing substances for the benefit of the organism.
For example, the amylase (enzyme) is in saliva and chemically changes amylose (starch) into sugars so food can be more easily processed for digestion.
Background
Amylose, Glucose, Sucrose, Fructose, Maltose, Dextrose, Lactose, etc... all have the suffix ose. This indicates that the all belong to a group of molecules call carbohydrates (contain carbon and water). Some carbohydrates are sugars and some are starches.
The carbohydrate that used in this activity is amylose (starch), which is found in many foods. We are also using an enzyme called amylase. The purpose of the lab is to start to understand what enzymes do / their role in living things.
Starch (Amylose) + Water, then Iodine
Starch (Amylose) + Amylase and Water, then Iodine
Background Knowledge:
We know from the Mystery Powder lab at the beginning of the year that iodine and starch turn purple. Thus, starch can be identified by turning purple with iodine.
Observations:
The test tube with just starch (amylose) and water turned purple when the iodine was added.
The test tube with starch (amylase), water and the enzyme amylase turned very light purple / did not change color when iodine was added to it.
Claims and Reasoning:
Since iodine turns starch (amylose) purple, the test tube that turned purple must have starch in it. In the other test tube, the same amount of starch was added but it did not turn dark purple, which means that this test tube did not contain starch or it contained less starch. Because this test tube also contained amylase, it must mean that the amylase changed the starch into a different substance via a chemical reaction. Since different substances have different properties, the new substance must be a different substance than starch because it did not turn purple.