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Teaching Guide
Counting Calories
The Anti-oxidant effects of Vitamin C
Testing for Simple Sugars
Educator Notes


  1. What did the Benedict's solution test for? (the presence of simple reducing sugars)
  2. How did the presence of a reducing sugar affect the Benedict's solution? (the Benedict's solution underwent a color change)
  3. What color would the Benedict's display if there was no sugar in the solution? (It would remain blue)
  4. What color would the Benedict's display if it tested a sugar (sucrose) solution? (the blue color wouldn't change since sucrose isn't a simple reducing sugar)
  5. Did these juices contain reducing sugars? How could you tell? (yes - the indicator solution underwent a color change when heated)
  6. Which juice underwent the most dramatic color shift? Why? (apple juice - it had the highest concentration of sugar)
  7. Which juice underwent the least change in color? Why? (lime juice - it had the lowest concentration of sugar)


This scale illustrates the relative sweetness of several sugars based upon
sucrose = 100
Lactose (complex sugar) = 16
Galactos (simple sugar) =32
Sucrose (complex sugar) =100
Fructose (simple sugar) =173

Using this scale, answer the following questions:


  1. Which is the sweetest of these four sugars? (fructose)
  2. How many times sweeter is sucrose than lactose? (6.25 times sweeter)
  3. How many grams of fructose would be needed to replace 10 grams of sucrose in order to produce the same sweetness? (1000/173 = 5.8 grams)
  4. Suppose a recipe calls for 5 grams of sucrose to sweeten a dish. How much lactose would be needed if you substituted sugars? (31.25 grams)
  5. If a diabetic has a low blood sugar level, that person may drink orange juice. Orange juice contains a high concentration of sugar that is readily used by the body. In contrast, some foods contain sugars that must be broken down before they can be used. These slow-release sugars may offer a diabetic a window in which a compromised insulin response has sufficient time to deal with the slowly rising sugar level. Think about it. Should a diabetic who is suffering from low sugar levels be given a food containing a slow-release sugar? (no) Explain. (The slow release will not offer an immediate source of sugar to patient)

 Chemical Reactions, Biochemistry, Indicators
 Ratios, Data Analysis
 Health, Nutrition

 Science As Inquiry-Content Standard A
 Students should develop abilities necessary to do scientific inquiry,
 Students should develop an understanding about scientific inquiry
 Physical Science -Content Standard B
 Students should develop and understanding of the properties and changes of  properties in matter
 Student should develop an understanding about transfer of energy
 Life Science -Content Standard C
 Student should develop an understanding about structure and function in living  systems
 Science in Personal and Social Perspectives -Content Standard F
Student should develop an understanding about personal health


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