Lesson 3 Exploring Carbohydrates

Objectives Recognize that carbohydrates are one of three major food types. Recognize that carbohydrates are one of three major food types. Indicate that sugar and starch are forms of carbohydrates. Indicate that sugar and starch are forms of carbohydrates. Perform chemical tests to determine the presence of sugar and starch in five foods. Perform chemical tests to determine the presence of sugar and starch in five foods. Explain that carbohydrates are a major source of energy for the human body. Explain that carbohydrates are a major source of energy for the human body.

Terms 3.1 Indicator 3.2 Carbohydrates 3.3 Sugar 3.4 Starches 3.5 Proteins 3.6 Amino Acids 3.7 Saturated Fats 3.8 Unsaturated Fats 3.9 Vitamins 3.10 Minerals 3.11 Water 3.12 Benedicts Solution 3.13 Lugols Solution 3.14 Complete Proteins 3.15 Incomplete Proteins 3.16 Fats 3.17 Monosaccharide 3.18 Polysaccharide

Question: How can you determine if sugar or starch is present in food?

Hypothesis: I believe you can determine the presence of sugar/starch by…because…

Data:

Safety!!!! Don’t taste or eat the food!!!! Don’t taste or eat the food!!!! Don’t touch the test tubes after they come out of the hot bath!!!! Don’t touch the test tubes after they come out of the hot bath!!!! Don’t get Benedict’s solution on your skin—if you do rinse it off immediately. Don’t get Benedict’s solution on your skin—if you do rinse it off immediately. Lugol’s will stain. Lugol’s will stain. If you get lugol’s on you—notify me immediately. If you get lugol’s on you—notify me immediately.

Procedure Mark the lab cups as indicated on page 17 in student guide. Mark the lab cups as indicated on page 17 in student guide. Mark the scoops 3, 4, 5 Mark the scoops 3, 4, 5 Using 6 test tubes, mark these 1-5 & DW. Using 6 test tubes, mark these 1-5 & DW. Add the materials in the cup according to the following chart. Add the materials in the cup according to the following chart. Stir each cup—use a different toothpick!!!!! Stir each cup—use a different toothpick!!!!!

Add the following materials to the lab cups as follows: 1 45 drops sugar solution 3 2 scoops potato buds 45 drops distilled water 5 2 scoops starch 45 drops distilled water 2 One Marshmallow 45 drops distilled water 4 2 scoops egg white 45 drops distilled water DW

Testing for Sugar Make sure the materials in each cup have been stirred. Make sure the materials in each cup have been stirred. Use a different pipette for each test tube Use a different pipette for each test tube In each test tube place 20 drops of the liquid that was in the cup. In each test tube place 20 drops of the liquid that was in the cup. Make sure the test tube # matches the cup #!!! Make sure the test tube # matches the cup #!!! Add 10 drops of Benedict’s solution to each test tube. Add 10 drops of Benedict’s solution to each test tube.

Testing for Sugar Attach the clamp to the test tube. Attach the clamp to the test tube. Two members of the group will take a test tube and place it in the water bath for one minute. Two members of the group will take a test tube and place it in the water bath for one minute. Do not hold onto the test tube while it is in the water bath. Do not hold onto the test tube while it is in the water bath. Repeat this procedure until all 6 test tubes have been heated. Repeat this procedure until all 6 test tubes have been heated. Record any color changes on the handout. Record any color changes on the handout.

Testing for Starch Make sure the sugar test has been completed. Make sure the sugar test has been completed. Add 3 drops of Lugol’s solution to each cup in the lab tray. Add 3 drops of Lugol’s solution to each cup in the lab tray. Look for color changes in the solid food instead of the liquid if the food hasn’t dissolved. Look for color changes in the solid food instead of the liquid if the food hasn’t dissolved. Record findings on the student sheet. Record findings on the student sheet.

Data/Results Record your results in your table Record your results in your table

Conclusion Write a paragraph stating your results. Be sure to discuss the role of Benedict’s and Lugol solutions. Write a paragraph stating your results. Be sure to discuss the role of Benedict’s and Lugol solutions.

Clean-up Roles Test-tube clean-up Lab-tray clean-up Pipette clean-up Lab Station clean-up Pour contents down sink/waste bucket. Scrub test tubes in soap water. Place in clean water bucket. Empty solids into trash. Rinse scoops in distilled water. Clean lab tray in soapy water. Rinse pipette in soapy water. Rinse in clean water Make sure all lids are back on all materials Put all materials back into tote tray.

Terms 3.1 Indicator 3.2 Carbohydrates 3.3 Sugar 3.4 Starches 3.5 Proteins 3.6 Amino Acids 3.7 Saturated Fats 3.8 Unsaturated Fats 3.9 Vitamins 3.10 Minerals 3.11 Water 3.12 Benedicts Solution 3.13 Lugols Solution 3.14 Complete Proteins 3.15 Incomplete Proteins 3.16 Fats 3.17 Monosaccharide 3.18 Polysaccharide

Terms 3.1 Indicator – Demonstrates the presence of a substance 3.2 Carbohydrates – Major source of energy for the body (sugars/starches) 3.3 Sugar – Occurs as Mono and Disaccharides. Form as glucose easily used by the body. 3.4 Starches – Polysaccharide. Must be broken down into Monosaccharide to be used by the body. 3.5 Proteins – Build and repair body. Made up of chain of amino acids. 3.6 Amino Acids – Make up proteins and are essential for health. 3.7 Saturated Fats – Comes from animals and can be converted into cholesterol (bad fats!) 3.8 Unsaturated Fats – Comes from plants, nuts, and seeds and is converted into energy (better fats!)

Terms 3.9 Vitamins – Chemicals made by living organisms Minerals – Chemicals made naturally in the environment Water – Nutrient in the body. H Benedicts Solution – Indicator for Sugar Lugols Solution – Indicator for Starch Complete Proteins – A food that has all 9 essential amino acids Incomplete Proteins – A food that does not have all 9 essential amino acids Fats – Provides energy and insulates the body Monosaccharide – Simple sugar. Provides energy Polysaccharide – Chain of sugars = Starch. Broken down to provide energy.