Part I: Predications

 

Name of food Glucose Starch Protein Lipid
Potatoes + +
Orange Juice + +
Almonds + + +
Eggs + + +
Salmon + +
Milk + + +

 

Instructions: General Information:

 

Carbohydrate Tests:

  • List the steps and reagents used to test for simple sugars or monosaccharides

Benedict’s reagent

Benedict’s reagent is used to identify the presence of simple sugars in a solution. For this test, the researcher took a test tube and added 2 ml of water to it. In the next step, the researcher added 2ml of the reagent to that test tube and heated the test tube for 5 minutes in boiling water and then recorded the color of the test tube. It turned to blue that indicated a negative test for the presence of glucose. In the next step, the researcher took a test tube and added 2ml of glucose and added 2ml of the reagent and heated this solution for 10 minutes. The color of the test tube changes to orange, which indicated the presence of glucose.

 

  • What does a positive reaction look like?

The orange color in the test tube indicates a positive test for glucose

  • What does a negative reagent look like?

The appearance of blue color in the test tube is an indication of a negative test for glucose.

 

  • List the steps and reagents used to test for starch.

Iodine Test for Starch

In the first step, I added 2 ml of iodine to 2ml of water in the test tube and the color of the test tube turned to yellow. In the second test tube, I added 2 ml of iodine to a starch solution and recorded the color of the test tube. The color of the test tube changed to dark brown.

In iodine test for starch, first, the researcher added 2ml of iodine solution to 2 ml of water and the color of the test tube turned red, which indicated a negative test for the presence of starch. Then, the researcher added 2ml of iodine to the starch solution and the color of solution turned black, which is a positive test for starch.

  • What does a positive reaction look like?

If the color of the solution turns to black, it is a positive test for starch.

  • What does a negative reagent look like?

If the color of the solution turn red after the addition of iodine, it is a negative test result.

 

Protein Test:

  • List the steps and reagents used to test for protein.

Biuret Reagent Test for Proteins

Proteins react with biuret reagent and turns the protein solution from light blue to violet, black. In the first step, the researcher took 2ml of water in a test tube and added 2ml of Biuret reagent and it did not change the color of the solution, which is an indication of negative test for protein. Then, the researcher added little amount of yellow colored protein in the test tube and added 2ml of biuret reagent to it, the color of the test tube changed to violet color, which indicated a positive test for protein.

  • What does a positive reaction look like?

If the addition of the biuret reagent change the color of the test tube to violet or black, it is a positive test for protein.

  • What does a negative reagent look like?

If there is no change in the color of the test tube or it changes t blue color, it is negative test.

 

 

Lipid Test:

List the steps and reagents used to test for lipids.

Sudan IV Test for Lipids

Sudan gets dissolved in lipids, but fails to dissolve in carbohydrates and proteins. The researcher took a test tube and added 2ml of water and added 2ml of Sudan reagent to it and it was not dissolved in it and showed 2 layers. In the next step, the researcher added 2ml of Sudan reagent to 2ml of vegetable oil and the color of the test tube changed to reddish orange. It was the positive test.

  • What does a positive reaction look like?

If the color of the test tube changes to reddish orange, it is a positive test result.

  • What does a negative reagent look like?

If there is no lipid in the test tube, Sudan reagent won’t be dissolved in the test tube and will show 2 layers.

 

Test for the Presence of Macromolecules:

Now that you are familiar with each test, use them to check your predictions and to determine the components of the foods listed.  Fill in the chart below according to your results.

 

Name of food Glucose Starch Protein Lipid
Potatoes +
Orange Juice + +
Almonds + +
Eggs + +
Salmon + +
Milk + + +

 

 

Analysis Questions:

  1. Compare your results to your predictions. Give one example in which your data supported your prediction and one example in which it did not.

One example where my prediction was supported by the tests was the presence of glucose in the milk. One example where my prediction proved incorrect was the presence of glucose in the eggs, which was proved incorrect by the simulation laboratory tests.

 

 

  1. From all the foods you tested in your group, which one would you eat if you….
  2. Needed quick energy-Explain.

 

In this case, I can consumer milk or orange juice as they contain glucose, which is a quick source of energy.

 

  1. Needed long term energy- Explain?

For this purpose, I could have almonds, fish and salmon as they all are rich sources of proteins.

 

  1. Were on a calorie-restricted diet- Explain.

For this particular case, I will go for almonds as they are rich source of fiber and contains fewer calories.

 

 

  1. Find a nutritional label at home and answer the following;
  2. Provide the name of the food

Kirkland, Organic Whole Milk

 

  1. What is the serving size and how many calories are in one serving?

Per Serving Size= 1 cup (240ml)

Calories per serving= 160

 

  1. How many servings are in one package?

It has 8 servings per container

 

  1. List the grams of total fat, total carbohydrates, fiber and protein per serving. What percentage of daily dietary intake of total fat and carbohydrates does the serving contain?

 

Name of the Ingredient Amount in one serving % of Daily Value of the Ingredient
Fiber Nil Nil
Fat 9 grams 12%
Carbohydrate           11 grams 4%
Protein            8 grams 16%

 

  1. Should this be a food that is part of your daily food intake? Why or why not?

Yes, this food could be a prat of my daily food intake as it is pure organic milk full of natural carbohydrates, proteins and fats. So, it can provide a good amount of % daily amounts of carbohydrates, fats and proteins. Moreover, it contains some more useful ingredients like vitamin A & D, calcium, iron and potassium, which all are very valuable dietary components.