Transcript HBS L-3
Lesson 3 Exploring Carbohydrates Objectives Recognize that carbohydrates are one of three major food types. Indicate that sugar and starch are forms of carbohydrates. 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. 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 3.13 3.14 3.15 3.16 3.17 3.18 Benedicts Solution Lugols Solution Complete Proteins Incomplete Proteins Fats Monosaccharide 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 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. Lugol’s will stain. 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 scoops 3, 4, 5 Using 6 test tubes, mark these 1-5 & DW. Add the materials in the cup according to the following chart. Stir each cup—use a different toothpick!!!!! Add the following materials to the lab cups as follows: 1 45 drops sugar solution 3 5 2 4 DW One Marshmallow 45 drops distilled water 2 scoops egg white 45 drops distilled water 45 drops distilled water 2 scoops potato buds 2 scoops starch 45 drops distilled 45 drops distilled water water Testing for Sugar Make sure the materials in each cup have been stirred. Use a different pipette for each test tube In each test tube place 20 drops of the liquid that was in the cup. Make sure the test tube # matches the cup #!!! Add 10 drops of Benedict’s solution to each test tube. Testing for Sugar 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. 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. Record any color changes on the handout. Testing for Starch Make sure the sugar test has been completed. 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. Record findings on the student sheet. Data/Results 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. Clean-up Roles Test-tube clean-up Pour contents down sink/waste bucket. Scrub test tubes in soap water. Place in clean water bucket. Lab-tray clean-up Empty solids into trash. Rinse scoops in distilled water. Clean lab tray in soapy water. Pipette clean-up Rinse pipette in soapy water. Rinse in clean water Lab Station clean-up 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 3.13 3.14 3.15 3.16 3.17 3.18 Benedicts Solution Lugols Solution Complete Proteins Incomplete Proteins Fats Monosaccharide 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. 3.10 Minerals – Chemicals made naturally in the environment. 3.11 Water – Nutrient in the body. H20. 3.12 Benedicts Solution – Indicator for Sugar. 3.13 Lugols Solution – Indicator for Starch. 3.14 Complete Proteins – A food that has all 9 essential amino acids. 3.15 Incomplete Proteins – A food that does not have all 9 essential amino acids. 3.16 Fats – Provides energy and insulates the body. 3.17 Monosaccharide – Simple sugar. Provides energy. 3.18 Polysaccharide – Chain of sugars = Starch. Broken down to provide energy.