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The Carb Lab Info

Page history last edited by Carol Hemmerly 14 years, 4 months ago

Testing for Carbohydrates in Foods

 

Purpose:  To test various foods for the presence of different types of carbohydrates

 

 

Materials:

Benedict’s solution                       water bottle               test tubes   test tube rack

Iodine solution                        food samples                       hot plate    known solutions

Test tube tongs               test plate               

 

Procedure:  

Part 1: Benedict’s Test

  1. Label four test tubes, with the wax pencil, monosaccharide, disaccharide, polysaccharide/starch and water.
  2. Using the known solution, add five drops of monosaccharide solution to the test tube labeled monosaccharide.
  3. Add five drops of Benedict’s solution to the monosaccharide test tube.
  4. Add 10 drops of water to the monosaccharide test tube.
  5. Repeat steps 1-4 only substitute the known monosaccharide solution with the known disaccharide, known polysaccharide/starch solutions and water.  You should have a total of 4 labeled test tubes.
  6. Heat the test tubes, one by one, in the hot water baths for 2 minutes.  (Use the test tube tongs so that you do not get burned.)
  7. After 2 minutes remove the test tube and observe the color.  Record your observations in table 1.
  8. Using the information gained from observing the reactions with the known solutions and the water, test the food samples provided using the above procedures but substitute the food samples for the known solutions.  (Do not put the known solutions into the test tubes with the food samples.)  Make sure to stir the contents of each test tube before heating.
  9. Record all observations in the table.
  10. Clean all test tubes with the brush and soapy water.

 

Part 2: Iodine test

  1. Place one drop of each known carbohydrate solution and water into their own well of the test plate.  (Be sure to label each well with a wax pencil.)
  2. Add one drop of iodine solution to each.  Record your observations in the table.
  3. Using the information gained from observing the reactions with the known solutions, test the food samples provided using the above procedures but substitute the food samples for the known solutions.  (Do not put the known solutions into the wells with the food samples.)  Clean out the wells of the test plate.  Throw all food materials in the trash, not in the sink!

 

 

________________________________________________________________________________________________________ 

 

 

 

The Molecules of Cells   (Chapter 3) 

 

Chapter Objectives 

 

Introduction To Organic Compounds 

3.1 Explain why carbon is unparalleled in its ability to form large, diverse 

molecules. 

3.1 Define organic compounds, hydrocarbons, a carbon skeleton.

3.2 Describe the properties of and distinguish between hydroxyl, amine, carboxyl, and phosphate chemical groups

3.3 List the four main classes of macromolecules. 

3.3 Explain the relationship between monomers and polymers.

3.3 Compare the processes of dehydration reactions and hydrolysis. 

 

Carbohydrates

3.4 List the elements that make up carbohydrates. (C, H, O)

3.4 Recognize the structure of glucose.

3.4 Explain the relationship among monosacchyrides, disacchyrides and polysacchyrides.

3.4 List other examples of monosacchyrides including fructose. 

3.5 List several examples of disacchyrides including lactose, maltose and sucrose.

3.5  Recognize the basic structure of a disacchyride.

3.5 Explain plants' use of sucrose.

3.5 Explain how disacchyrides are formed (dehydration reaction) and broken down

(hydrolysis).

3.7 List several examples of polysacchyrides including starch, glycogen, cellulose and chitin.

3.7 Recognize the basic structure of a polysacchyride.

3.7 Outline the function/ uses of each.

3.7 Explain how polysacchyrides are formed (dehydration reaction) and broken down (hydrolysis).

 

Lipids

3.8 List the elements that make up lipids. (C, H, O)

3.8 Outline the general characteristics of fats and oils.

3.8 Outlines the importance of fats, waxes and oils to organisms.

3.8 Compare energy storage of fats and oils to carbohydrates.

3.8 Describe and recognize the basic structure of a triglyceride.

3.8 Compare and contrast saturated and unsaturated fats/ fatty acids.

3.9 Outline the function/ importance of steroids and phospholipids.

3.9 Describe hydrophobic and hydrophilic properties of phospholipids.

3.10 Outline the health risks associated with the use of anabolic steroids.

 

 

Proteins

3.11 Outline the functions of proteins in organisms.

3.12 List the elements that make up proteins. (C, H, O, N)

3.12 Name the monomer of proteins.

3.12 Describe peptide bond dehydration reactions and hydrolysis reactions.

3.12   Recognize the basic structure of an amino acid.

3.13-3.14 Explain the importance of a protein's shape to its function.

3.13-3.14 Define denaturation.

3.13-3.14 Explain the consequence of denaturation to the function of proteins.

3.13-3.14 Describe the detrimental effects of a high fever.

3.13-3.14 Outline the four levels of protein structure.

3.13-3.14 Describe the importance of primary structure to all further levels.

 

Nucleic Acids

3.16   Outline the functions of nucleic acids.

3.16   List the elements that make up nucleic acids.

3.16   Describe the basic structure of nucleic acids.

3.16   Recognize the structure of nucleotides and nucleic acids.

 

 

Key Terms 

alpha helix amine amino acid amino group anabolic steroid carbohydrate carbon skeleton cellulose chitin  cholesterol dehydration reaction denaturation  deoxyribonucleic acid (DNA)  disaccharide double helix enzyme fat functional group gene glycogen hydrocarbon hydrolysis hydrophilic hydrophobic lipid macromolecule monomer 

monosaccharide nucleic acid nucleotide organic compound peptide bond phospholipid   polymer polypeptide  polysaccharide primary structure protein  quaternary structure ribonucleic acid(RNA) saturated secondary structure starch  steroid  tertiary structure unsaturated  

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