Victory for the ACT Student Text 15e

L ESSON 2 | R ESEARCH S UMMARY • 309

Table 3

Substance Distilled Water Sucrose Solution Glucose Solution Heavy Cream Whole Milk

Negative Negative Negative Positive Positive

Presence of Lipids

No-Fat Milk Positive Unsweetened Soy Milk Negative

Experiment 3 Starch is a molecule found only in plants. Lugol’s iodine is used as an indicator test for the presence of starch in organic compounds, with which it reacts by turning a blue-black color. The students performed a third experiment in which 2 milliliters of each of the liquids used in Experiments 1 and 2 were pipetted into pre-labeled test tubes. Three drops of Lugol’s solution were added to each test tube, and the students recorded the results in Table 4. Table 4 Substance Presence of Starch Distilled Water No Change Sucrose Solution No Change Glucose Solution No Change Heavy Cream No Change Whole Milk No Change No-Fat Milk No Change Unsweetened Soy Milk Turned Blue-Black 7. According to the information provided, whole milk contains what percentage lactose by weight? A. 0.0% B. Between 0.2% and 3.5% C. Between 3.6% and 5.0% D. More than 5.0% 8. Which of the test substances in Experiment 2 functioned as a control? F. Distilled water G. Heavy cream H. No-fat milk J. Unsweetened soy milk 9. Which substances tested positive for both lipids and reducing sugars? A. Glucose only B. Whole milk and heavy cream only C. Whole milk, heavy cream, and no-fat milk only D. Whole milk, heavy cream, no-fat milk, and unsweetened soy milk only