HW #1 Molecules of Life Packet

Transcription

1 Name Hour Due: HW #1 Molecules of Life Packet Lab Molecule ID Chemistry Fats, carbs WS HW Page 1 Page 2 Your Points Total Points Possible 5 pts Macromolecules in Foods Lab

2 Introduction: The food we eat is full of the molecules that our bodies need to build and maintain a complex organism like a human being. This food is digested or broken down into its building blocks and then used to build the specific structures our body needs. Proteins are broken down into amino acids and used to build the specific protein molecules that each cell needs. Carbohydrates are broken down and then rebuilt to coat our cells or to store energy in the form of glycogen in our liver. Sugars can be converted to fats for storage for lean times. Fats can also be used to form phospholipids (to build cell membranes) or to build many of the hormones that regulate our bodies. Side note: When doing this lab, you will find that some foods have a strong reaction and some have a slight reaction. This is indicative of the quantity of that product within the food item. Remember, if there is a change in coloration, there is a reaction taking place. bjectives: Determine the presence of starch by a chemical test Analyze a glucose solution for the presence of simple reducing sugars Analyze a sample of vegetable oil for the presence of lipids Analyze a sample of amino acids for the presence of proteins Determine the macromolecules present in a variety of food samples Procedure: Part A: Lipids test 1. Take a piece of brown paper and make 9 circles on the paper. Number the circles Place 1 drop of vegetable oil in the circle labeled Repeat this process with each of the food items (2-9) on the appropriately numbered section of the paper. Be careful not to let the solutions mix on the paper. 4. Place the brown paper on your lab bench for about 3-5 minutes. 5. Hold the paper up to the light. If a semi-transparent spot is evident the sample contains lipids. 6. Record the appearance of the spots in table Dispose of brown paper in the garbage HW D YU KNW IF SMETHING CNTAINS LIPIDS? (Be specific. Use complete sentences).

3 Part B: Test for Proteins 1. Label 9 test tubes, 1 through 9, and place in test tube rack. 2. Put 2 ml of Protein solution into test tube labeled Place 2 ml of apple sauce into test tube Repeat this process using each of the food items listed in the data table. Be sure to place each item in the correctly labeled test tubes (3-9). 5. Add 5 ml of Biuret s solution to each test tube. 6. bserve the color change in comparison to the control. 7. Record the results of test tubes 2-9 in Table 1. It will turn purple if there is protein present, if not it stays blue. 8. Discard substances, wash test tubes with soapy water and rinse clean with water. HW D YU KNW IF SMETHING CNTAINS PRTEINS? (Be specific. Use complete sentences). Part C: Starch Test 1. Label 9 test tubes, 1 through 9, and place in test tube rack. 2. Put 2 ml of Starch in test tube labeled Place 2 ml of apple sauce into test tube Repeat this process using each of the food items listed in the data table. Be sure to place each item in the correctly labeled test tubes (3-9). 5. Add 3 drops of iodine solution to each test tube. 6. Record the color change in each of the tube in the table below. (Remember, if it turns a blue-black color then starch is present) Record the appearance of the spots in the table below. 7. Discard substances, wash test tubes with soapy water and rinse clean with water. HW D YU KNW IF SMETHING CNTAINS STARCH? (Be specific as to what the color change is.) Part D: Reducing Sugar test 1. Label 9 test tubes, 1 through 9, and place in test tube rack. 2. Put 2 ml of Simple Sugars solution into test tube labeled Place 2 ml of Apple sauce into test tube Repeat this process using each of the food items listed in the data table. Be sure to place each item in the correctly labeled test tubes (3-9). 5. Add 2 ml of Benedict s solution to each of the test tubes (1-9) and place in the hot water bath for 3 minutes. (remember, if it turns a reddish brown, green or yellow then a monosaccharide or some disaccharides are present).

4 6. Remove test tubes from water using a test-tube holder and place them in test tube rack. 7. Record the appearance of the test tubes in the below table. 8. Discard substances, wash test tubes with soapy water and rinse clean with water. HW D YU KNW IF SMETHING CNTAINS REDUCED SUGAR? (Be specific as to what the color change is.) Table 1. FD ITEM Contains Starch? Contains Simple Contains Contains Fats? Sugars? Proteins? 1. Control Apple Sauce 3. Egg 4. Gelatin 5. Cream 6. Skim Milk 7. Syrup 8. Energy Drink 9. Mashed Potato Mix

5 Unknown Contains fats? Contains starch? Contains simple sugars? Contains Proteins? Analysis: 1. Which of the food items that we tested would be good to eat if you wanted a quick burst of energy? 2. ne of the main building blocks of muscle is amino acids. Why did the sports drink contain protein? 3. The sports drink only had one type of carbohydrate. Which one did it have and explain why it had only this one type of carbohydrate. 4. Which of the foods above contain protein? How do you know? 5. What do proteins have that nucleic acids, carbohydrates, and fats don't have that might turn the Biuret reagant from blue to purple? 6. Biuret s reagant will turn your skin purple. Explain why this occurs?

6 7. Using the results that you obtained for skim milk and cream, predict the results of 2% milk for each of the tests. Starch test Simple sugar test Lipid test Protein test 8. Complete the following chart: Type of macromolecule Proteins How is it used by the body? Fats Carbohydrates 9. List some dangers that may be associated with no fat diets?

7 Biological Chemistry Worksheet Answer each of the following questions. You may have to do some research to find the appropriate information concerning some of the molecular formulas. Background Questions 1. At the minimum, all organic molecules have which two elements? 2. Is water an organic molecule? Explain. 3. Look at the diagrams on the last page. In which section are there diagrams of proteins? How do you know? 4. Look at the diagrams on the last page. In which section are there diagrams of lipids? How do you know? 5. Look at the diagrams on the last page. In which section are there diagrams of carbohydrates? How do you know? 6. Match each organic molecule with its function in the body carbohydrate proteins lipids A. long-term energy; insulation B. energy; cell wall; exoskeleton C. many including antibodies and hair 7. Which organic molecule did we discuss in great detail last semester? 8. Look at the diagrams on the last page. What is the chemical formula of serine? 9. In space below, draw the general structural formula for: GLUCSE LIPIDS

8 Carbohydrates 1. If you were to join two monosaccharides together via dehydration synthesis, what type of carbohydrate would you have? 2. Whenever you join sugars together, you remove an H from one sugar and a +H from the other to form HH, also known as...? 3. The process of losing water as organic molecules are connected is called or 4. What is the chemical formula for glucose? C H 5. What is the chemical formula for fructose? C H 6. So if you chemically join glucose with a fructose, you create sucrose which is a disaccharide. What would be the resulting molecular formula for sucrose? C H * Did you remember to remove a water molecule? 7. Now join three glucoses together to form a simple polysaccharide. What molecular formula do you get? C H * Did you remember to remove two water molecules? 8. As a final test to see if you understand molecular formulas and dehydration synthesis, what should be the molecular formula if nine glucoses were joined together to create a large polysaccharide? C H * How many water molecules did you remember to remove?

9 Proteins 1. From the diagrams on the last page, choose two different amino acids. Name them and draw their structural formulas. Amino Acid #1 Amino Acid #2 2. Create a drawing (structural formula) that shows your two amino acids linked together. To connect them, the H from the acid group and the H from the amine group need to be removed. (Remember dehydration synthesis). Be sure to clearly label the peptide bond. 3. In order to separate organic molecules, water is added back in during the process of. 4. Illustrate the process of hydrolysis showing your two amino acids splitting apart through the addition of a water molecule.

10 Fats/Lipids 1. Draw the structural molecule of glycerol. 2. Draw a saturated fatty acid that has a carbon skeleton containing 4 carbon atoms. This is butyric acid. 3. Now combine three of these butyric acids to your glycerol molecule. Draw the resulting lipid. 4. How many water molecules were released during the above dehydration synthesis reaction?

11 A Glucose Serine Valine Methionine B C

12 Molecules of Life Homework Packet Name the following molecule: 1. etc. CH 2 H H H CH 2 H H H CH 2 H H H CH 2 H H H etc Match the molecules with their use in living organisms. DNA lipids carbohydrates C 2 glucose glycerol amino acids protein a. membrane construction b. store energy c. store information for making proteins d. used to make fats e. blood sugar f. waste gas of animals g. used to build and control the organism h monomer used to build proteins

13 5. Draw the structure of a fatty acid that is unsaturated: 6. Draw a peptide bond between two amino acids of the general formula (Hint: think R ). 7. Why do living organisms need carbon? Fatty acids? Carbon? Fatty Acid? 8. If you have six glucose molecules and link them together using dehydration synthesis(condensation), a) How many bonds would you have? b) How many water molecules come out? a. b. 9. What are the products of the hydrolysis of maltose? 10. Draw a carboxyl group below: