Data Table 1. Sugar Tests with Benedict’s Reagent. Test tube number Substance Hy

Question

Data Table 1. Sugar Tests with Benedict’s Reagent.

Test tube
number

Substance

Hypothesis

Final color

Test results for
reducing sugar

1

Distilled water

2

Glucose solution

3

Starch solution

4

Table sugar

5

Splenda®

6

Sweet'N Low®

7

Milk

8

Juice

9

Potato

Questions

1. Did the table sugar solution test positive or negative for reducing sugars? Explain why you received these

2. Do Splenda® and Sweet’N Low® test positive or negative for reducing sugars? List the ingredients found in each of these products. Underline the ingredient that is the artificial sweetener. (Hint: There is only one artificial sweetener in each of the products. Refer to the Introduction.)

3. What is the relationship of glucose and dextrose? How does this relationship influence the test results for Splenda® and Sweet’N Low®?

4. A common artificial sweetener found in Equal®, NutraSweet®, and many diet sodas is aspartame (C14H18N2O5). Would a sample of pure aspartame test positive or negative for reducing sugars? (The pure sample does not contain other ingredients, such as dextrose, maltodextrin, or calcium silicate.)

5. Unlike other sweeteners, Splenda® may be used in cooking because it does not break down at higher temperatures. Many recipes call for Splenda® instead of table sugar. Is a cake baked with Splenda® actually sugar-free? How might this affect a person concerned with blood sugar levels?

Exercise 2: Detection of Starch

Data Table 2. Starch Tests with IKI Indicator.

Test tube
number

Substance

Hypothesis

Final color

Test results for starch

1

Distilled water

2

Glucose solution

3

Starch solution

4

Table sugar

5

Splenda®

6

Sweet’N Low®

7

Milk

8

Juice

9

Potato

Questions

1.Which sugar substitute tested positive for presence of starch? This sugar substitute contains a starch derived from corn or potatoes. List the ingredient that is the starch.

2. List three examples of polysaccharides in living organisms. Describe the structural orientations of each.

3. When a human consumes starch, the polysaccharides are broken down into simple sugars, which are converted to polysaccharides for storage in the cells. However, simple sugars are used by the cell to perform work. Describe why it is necessary to change the form of the carbohydrate in the body.

Exercise 3: Converting Starch to Sugar

Data Table 3. Conversion of Starch to the Sugar Maltose.

Test tube
number

Substance +
-amylase

Final color

Test results for
reducing sugar

Test results for
starch

1

Distilled water

----------

2

Distilled water

----------

3

Starch solution

----------

4

Starch solution

----------

Questions

1. What type of reaction is the conversion of starch to maltose? Describe what occurs during the reaction.

2. Is maltose a reducing sugar or a non-reducing sugar? Support your answer with information in Data Table 3. Maltose is a reducing sugar. Explain why by finding a supporting reference.

Test tube
number

Substance

Hypothesis

Final color

Test results for
reducing sugar

1

Distilled water

2

Glucose solution

3

Starch solution

4

Table sugar

5

Splenda®

6

Sweet'N Low®

7

Milk

8

Juice

9

Potato

Explanation / Answer

Data table 1:

Table sugar is sucrose, a disaccharide composed of the monomers glucose and fructose in 1-à2 linkages (-D-glucopyranosyl-(1-à2)--D-fructofuranoside. The bond formation involves reducing ends of both the sugars and thus, the disaccharide is a non-reducing sugar.

Relevant information is missing

Dextrose is D-glucose. It is D isomer of glucose

Aspartame contains amino acids L-aspartic acid and L-phenylalanine. There are no sugars in this product. The methyl ester of the dipeptide is sold in the commercial name Aspartame. Since there is no reactive group or reducing groups in the dipeptide, it shows negative result for reducing sugars.

No. The cake baked with Splenda is no sugar free. Actually, Splenda itself is not sugar free. It contains a mixture of Dextrose and maltodextrin (95%) and the remaining 5% is a sucralose derivative.The dextrose and maltodextrin of this compound are readily absorbed by the body. They elevate the blood of sugar levels of diabetics immediately after their consumption.

Related Questions

Navigate

• Browse (All)
• Browse D
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.