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Teacher’s Guide EXPLORE Part I: Testing Known Substances Teacher Prep: 1. Prepare and label four Erlenmeyer flasks and disposable pipettes with the following suggested solutions and place them in the front of the room for easy access for students: a. Polysaccharide Solution - blended potato or lab grade starch solution b. Monosaccharide Solution – apple juice or lab grade glucose solution c. Protein Solution – blended meat or egg whites d. Lipid Solution – vegetable oil, melted butter 2. Set up 4 lab stations (twice around the room) for students to rotate. Each station should have the materials needed to conduct one of the following tests: a. Iodine Test: starch + iodine (yellowish orange) blue-black Ex. Potato solution b. Benedict's Test: monosaccharide + Benedict's solution (light blue) green to red depending on concentration of sugars Ex. apple juice or glucose solution c. Biuret's Test: protein solution + Biuret’s solution (light blue) pinkish purple Ex. meat , egg white d. Paper Bag (Translucence) test 3. At each station, have the indicator test procedure card, the biomolecule information card for the biomolecule being tested at the station, and all lab supplies required to conduct the test. It is recommended that the two lab stations in the front be designated for the Benedicts test which requires a hot water bath. Procedure 4. Have students read the background information and complete the Pre-Lab questions for Part 1 as the journal activity for the day. 5. Demonstrate to students what equipment and basic procedures they will be applying during this exercise. 6. Have students get into groups of 2-3 and rotate through all 4 stations and record their results. 7. Have students return to their desks but stay with their groups to complete the Analysis Questions in their journals. Alternate indicators: Iodine for lipids/oil (turns pink but transformation is temporary so watch carefully) Biuret Solution is easy to make. Start with 40% NaOH and then sprinkle in copper sulfate until you get a nice blue color. Nitric acid for proteins (turns yellow in the presence of proteins, stays clear if none are present). o Students need to take the proper cautions when working with nitric acid to prevent contact with skin or clothing. It becomes really easy to see who did not take proper precautions because they can be caught yellow-handed. Water solubility test for fats (the presence of fats makes an insoluble layer on top of the water). This test can be difficult at times to detect based on the type of substance and amount of fat in it. Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm ELABORATE Part II: A Lesson in Urinalysis Teacher Prep: 1. Prepare and label four Erlenmeyer flasks and disposable pipettes with the following synthetic urine solutions and place them in the front of the room for easy access for students: Synthetic Urine Recipes Each student group needs about 10 mL of a sample for testing. These recipes make about 60 mL of each sample. Stock Urine: 160mL water Yellow food coloring 2g NaCl Urine Sample from Patient #H 987 (High glucose) 40mL apple juice 20mL stock urine Urine Sample from Patient #L 623 (High protein) 60mL stock urine 5mL egg albumin Urine Sample from Patient #P 552 (High glucose & protein) 40mL apple juice 20mL stock urine 5mL egg albumin Urine Sample from Patient #M 340 (High protein & High starch – contaminated sample!) 50mL stock urine 5mL egg albumin 5mL starch 2. Set up 3 lab stations (2-3 times around the room) for students to rotate. Each station should have the materials needed to conduct one of the following tests: a. Iodine Test: starch + iodine (yellowish orange) blue-black Ex. Potato solution b. Benedict's Test: monosaccharide + Benedict's solution (light blue) green to red depending on concentration of sugars Ex. apple juice or glucose solution c. Biuret's Test: protein solution + Biuret’s solution (light blue) pinkish purple Ex. meat , egg white Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm 3. At each station, provide the Macromolecule Lab: Urinalysis experimental procedure and all lab supplies required to conduct the test. It is recommended that the 1-2 lab stations in the front be designated for the Benedicts test which requires a hot water bath. 4. As the journal questions for the day have students complete the Pre-Lab questions for Part 1. 5. Demonstrate to students what equipment and basic procedures they will be applying during this exercise. 6. Have students get into groups of 2-3 and rotate through all 4 stations and record their results. 7. Have students return to their desks but stay with their groups to complete the Analysis Questions in their journals. Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm Macromolecule Lab: Using Indicators Purpose The purpose of this exercise is to determine how to use chemical indicators to verify the presence of carbohydrates (monosaccharides and polysaccharides), proteins, and lipids in several known substances. Background Carbohydrates, proteins, and lipids are nutrients that are essential to all living things. Most foods contain mixtures of proteins, carbohydrates, and lipids. These food molecules taken into cells react to provide the chemical building blocks needed to synthesize other molecules used for processes that the body carries out, like growth and reproduction. The atoms that make up the macromolecules (carbon, oxygen, and hydrogen in particular) occur in different ratios and structures that account for different properties. Indicators are chemical substances that can be used to classify the types of macromolecule present in substances. The indicators will turn color due to the structural differences among the macromolecules. The individual classes of macromolecules can be described as follows. A carbohydrate is an organic compound composed of carbon, hydrogen, and oxygen atoms in the ratio of about two hydrogen atoms to one oxygen atom. A protein is organic molecule that is formed from amino acids. An amino acid consists of a central carbon atom to which four functional groups are attached. Most lipids contain fatty acids and glycerol. Nucleic acids are organic molecules that store genetic information in the cell. SAFETY: Pre-Lab – Answer the following pre-lab questions using complete sentences in your lab journals. 1. What are the four main biomolecules found in living things? 2. What is an indicator? How will they be used in this lab? 3. Based on the safety symbols below, what precautions will you expect to take in order to perform this investigation? Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm Part I: Testing Known Substances In the first part of this lab, you will need to determine how to use chemical indicators to verify the presence of monosaccharides and polysaccharides, proteins, and lipids in several known substances. Your results in this section will allow you to carry out tests on a “patient’s” urine samples to determine the presence of any of the above known substances. Procedure 1. Draw or paste the following data table in your journal. Chemical Macromolecule Indicator Biuret’s Solution Benedict’s solution Lugol’s Iodine Initial Observation Observations for a Positive Test Paper Bag 2. Visit each of the stations set up in the classroom. Follow all instructions carefully and make detailed observations in the data chart to assist you in Part II. 3. When your group has completed all the tests at each station, return to your desks and discuss what you have discovered during this investigation. 4. Be ready to participate in a class discussion and complete an exit ticket. Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm Analysis Questions (Answer in complete sentences in your journal): 1. Which substances contain monosaccharides? a. Which substances contain starch? b. Which substances contain protein? c. Which substances contain lipids? 2. Which substances did not test positive for any of the organic compounds? 3. What is the purpose of using distilled water as one of your test substances? 4. What do all of the indicators you have used have in common? 5. What conclusions could you make if a positive test for any of the organic compounds occurred in the test tube containing distilled water? 6. How does an indicator detect the presence of only one type of macromolecule? 7. Is there a macromolecule that the tests in this lab did not test for? If so, list the kinds of macromolecules not tested, and give one reason why they were not tested. 8. Which compound is most common in foods that come from plants? 9. If you wanted to reduce the amount of fat in your diet, what foods would you avoid? 10. Which foods tested would your body use for a quick burst of energy? a. For energy when no carbohydrates are available? b. For building body parts? __ ____ ____ Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm _ ______Part I Protein Test Station Card - Biuret Solution Materials Substance tested Protein solution Indicator - Biuret solution Test tubes Dropper Supplies to clean and dry test tubes Procedure 1. This is the station where you will use Biuret’s solution to test for the presence of proteins. 2. Locate a test tube, the protein solution, and the Biuret solution. 3. Shake the protein solution. Then add 1-2 drops into the test tube. 4. Now, add 2-3 drops of Biuret solution. Swirl the solutions together. 5. Record any observable change in color. 6. Replace all materials. Clean out your test tube using soap, water, and a test tube brush. Place your test tube into the rack to dry. Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm Lipid Test Station Card - Paper Bag Materials Substance tested – Lipid (vegetable oil ) solution Indicator - Paper bag Dropper Test tubes Procedure 1. This is the station where you will use the paper bag test to check for the presence of lipids (fats). 2. Obtain a test tube, the vegetable oil, and a piece of brown paper bag. 3. Add 1-2 drops of vegetable oil to the brown paper. Record what you see. Describe how the paper looks. 4. Repeat step 3 using water on a different piece of brown paper. Record what you see. 5. Compare your two results and come up with a good description of how the paper test can be used to test the presence of lipids. 6. Replace all materials. Clean out your work area. Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm Monosaccharide Test Station Card - Benedict’s solution Materials Substance tested Monosaccharide solution Indicator - Benedict’s solution Test tubes Hot water bath Test tube holder Dropper Supplies to clean and dry test tubes Procedure 1. This is the station where you will use Benedict’s solution to test for the presence of monosaccharides (simple sugars). 2. Locate a test tube, a test tube holder, the monosaccharide solution, and the Benedict’s solution. 3. Add 4-5 drops of the monosaccharide solution to the test tube. 4. Now, add 4-5 drops of the Benedict’s solution. Swirl the solutions together. 5. Carefully place your test tube into the hot water bath using the test tube holder. (Caution: water is HOT!) 6. Record the change in color that is seen (green indicates a low concentration of monosaccharides – brick red indicates a high concentration). Also, note how long it took for the color to change. 7. Replace all materials. Clean out your test tube using soap, water, and a test tube brush. Place your test tube into the rack to dry. Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm Polysaccharide Test Station Card - Lugol’s Iodine Materials Substance tested Polysaccharide (Starch) solution Indicator - Iodine solution test tube Dropper Supplies to clean and dry Procedure 1. This is the station where you will test for the presence of polysaccharides (starch). 2. Shake the polysaccharide (starch) solution. Then add 1-2 drops into the test tube. 3. Note the color of the iodine solution. Now, add 1-2 drops of the Iodine solution. 4. Record the change in color that you observe. 5. Replace all materials. Clean out your well plate using soap and water. Place your well plate on the paper towel to dry. Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm Cut and paste into lab notebook. Chemical Indicator Macromolecule Initial Observation Observations for a Positive Test Initial Observation Observations for a Positive Test Biuret’s Solution Benedict’s solution Lugol’s Iodine Paper Bag Cut and paste into lab notebook. Chemical Indicator Macromolecule Biuret’s Solution Benedict’s solution Lugol’s Iodine Paper Bag Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm Lab: Macromolecule - A Lesson in Urinalysis Background A healthy diet abundant with foods that contain each of the macromolecules insures proper function of all the body’s cells, tissues, organs, and organ systems. If one or more are lacking, the body cannot function to provide us with all of our necessary needs. Your kidneys filter waste products from your blood while retaining components your body needs — including proteins and sugars. The kidneys take out waste material, minerals, fluids, and other substances from the blood to be passed in the urine. Urine has hundreds of different body wastes. What you eat, drink, how much you exercise, and how well your kidneys work can affect what is in your urine. Urine can contain important information about a patient’s (human or animal) health status. A test called a urinalysis, or “UA”, is done to check for infections of the urinary tract or for the presence of blood, glucose, or protein in the urine. The composition of urine varies depending on diet and activity. Urine is about 95% water, but it also contains urea and uric acid. Sometimes traces of amino acids can be found in urine, as well as a variety of electrolytes. In this activity, you will be analyzing a “patient’s” urine for the presence of carbohydrates, proteins, or lipids. Glucose is the type of sugar found in blood. Normally there is very little or no glucose in urine. When the blood sugar level is very high, as in uncontrolled diabetes, the sugar spills over into the urine. Glucose can also be found in urine when the kidneys are damaged or diseased. Some diseases and conditions can allow proteins to pass through the filters of your kidneys, causing protein in urine. Protein is normally not found in the urine. Low levels of protein in urine are normal. Temporarily high levels of protein in urine aren't unusual either, particularly in pregnant individuals, younger people after hard exercise, or during an illness. However, abnormally high amounts of protein found in a urine (proteinuria or microalbuminuria) is often a sign of kidney disease and can be used to detect the early signs of kidney damage. Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm Pre-Lab Questions – Answer the following pre-lab questions in complete sentences in your lab journals. 1. What are the monomers of protein, and what element(s) do they contain that carbohydrates and lipids do not? 2. Explain why you have to test for the presence of macromolecules in known substances first before you test unknown samples? 3. Using the following sentence stem, formulate a hypothesis regarding your patient’s urine sample. If Patient # _______’s urine tests positive for (protein/glucose/starch), then his/her sample indicates a (contaminated sample/risk of diabetes/sign of kidney disease). Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm MATERIALS Urine sample* Patient #M 340 Patient #P 552 Patient #L 623 Patient #H 987 Macromolecule Lab: Urinalysis Purpose To test urine samples for the presence of monosacchrides, polysaccharides, and protein in order to diagnose a patient with diabetes or kidney disease. 3 test tubes Test tube rack Test tube tongs Biuret solution Iodine solution Benedict’s solution Hot plate with water bath Procedure Part 2 SAFETY 2. Conduct the following three tests on the urine sample: a. Monosaccharide (Simple sugar) Test Add 1-2 drops of the urine sample to a clean test tube. Add 1-2 drops of Benedict’s solution to the sample. Heat the sample for 1-2 minutes in a hot water bath. Record your results in the data table. 1. Draw the following data table in your lab journal. Urine Sample #: Macromolecule Chemical Indicator Prediction Present (+) Absent (-) Monosaccharide (simple sugar) Polysaccharide (starch) Protein b. Polysaccharide (Starch) Test Add 1-2 drops of the urine sample to a clean test tube. Add 1-2 drops of Lugol’s iodine solution to the sample. Record your results in the data table. c. Protein Test Add 1-2 drops of the urine sample to a clean test tube. Add 1-2 drops of Biuret’s solution to the sample. Record your results in the data table. Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm 3. When your group has completed all the tests at the stations, return to your desks and discuss what you have discovered during this investigation. Make your diagnosis based on your data. 4. Be ready to participate in a class discussion and complete a conclusion paragraph as an exit ticket. Conclusion In paragraph form, write a summary of the experiment, analysis of data, and a discussion of any sources of error if any occurred. Make sure to include the following information in your conclusion paragraph(s): a) For which patient did you do your urinalysis tests? b) What was your original hypothesis? c) What was the independent variable in your experiment? d) What was your dependent variable? e) What were your results? Which macromolecule(s) were present in your patient’s urine? f) Did your results support your hypothesis? g) Can you make a diagnosis about your patient? If so, what is it? h) Where there any errors in your tests that could have affected your results? Niesen, Lorilee (2008). Macromolecule Lab; A Lesson in Urinalysis. Maxwell High School Ag. Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm Name _____________________________________________ Date ___________________ Period __________ EXIT TICKET: Urinalysis Patient #5150 A student conducted a urinalysis test on two urine samples. Evaluate the results and indicate which macromolecules are present and explain why. Patient #5150: Purple-black iodine, green Benedict’s solution, blue Biuret Answer: Name _____________________________________________ Date ___________________ Period __________ EXIT TICKET: Urinalysis Patient #5150 A student conducted a urinalysis test on two urine samples. Evaluate the results and indicate which macromolecules are present and explain why. Patient #5150: Purple-black iodine, green Benedict’s solution, blue Biuret Answer: Name _____________________________________________ Date ___________________ Period __________ EXIT TICKET: Urinalysis Patient #5150 A student conducted a urinalysis test on two urine samples. Evaluate the results and indicate which macromolecules are present and explain why. Patient #5150: Purple-black iodine, green Benedict’s solution, blue Biuret Answer: Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm Name _____________________________________________ Date ___________________ Period __________ EXIT TICKET: Urinalysis Patient #0560 A student conducted a urinalysis test on two urine samples. Evaluate the results and indicate which macromolecules are present and explain why. Patient #0560: Light brown iodine, red Benedict’s solution, pinkish-purple Biuret Answer: Name _____________________________________________ Date ___________________ Period __________ EXIT TICKET: Urinalysis Patient #0560 A student conducted a urinalysis test on two urine samples. Evaluate the results and indicate which macromolecules are present and explain why. Patient #0560: Light brown iodine, red Benedict’s solution, pinkish-purple Biuret Answer: Name _____________________________________________ Date ___________________ Period __________ EXIT TICKET: Urinalysis Patient #0560 A student conducted a urinalysis test on two urine samples. Evaluate the results and indicate which macromolecules are present and explain why. Patient #0560: Light brown iodine, red Benedict’s solution, pinkish-purple Biuret Answer: Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm Carbohydrates Function Carbohydrates are found in foods such as: Simple sugars include: table sugar and honey Living things use carbohydrates as their main source of energy. Plants and some animals also use carbohydrates for structural purposes. Starches and sugars are examples of carbohydrates that are used by living things as a source of energy. Complex carbohydrates include: Grains, cereals, and pasta Breads, tortillas, crackers, bagels Dried beans, split peas and lentils Vegetables, like potatoes, corn, and peas Fruit Milk and yogurt Foods and drinks made with sugar, like regular soft drinks and desserts Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm Glucose is the most common sugar unit in our food and in our bodies. Besides glucose, monosaccharides include galactose, which is a component of milk, and fructose, which is found in many fruits. The polysaccharide, starch, is stored in plant fruits and seeds. Another carbohydrate found in plants is cellulose, a very straight and stiff material, which is a major component of cell walls. Animal starch, glycogen, is stored in the liver of many animals. Structure One of the four groups of organic compounds found in living things is carbohydrates. Carbohydrates are compounds made up of carbon, hydrogen, and oxygen atoms, usually in a ratio of 1:2:1, for example, glucose has the formula C6H12O6. The building blocks of carbohydrates are ring shaped molecules called monosaccharides (mohn-oh-SAK-uh-rydz). Glucose is an example of a monosaccharide. Carbohydrate is sugar – and includes both single sugar units called monosaccharides and chains of sugar units chemically linked together called polysaccharides (poh-li-SAK-uh-rydz). Starches form when sugars join together in a long chain. Carbohydrates have to be broken down into single sugar units to be absorbed. Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm Lipids One of the four groups of organic compounds found in living things are lipids. Lipids are a large and varied group of biological molecules that are generally insoluble (does not dissolve) in water. The common categories of lipids are fats, oils, and waxes. A fat is a solid at room temperature, while an oil is a liquid under the same conditions. Lipids are made mostly from carbon and hydrogen atoms. The building blocks of lipid molecules are fatty acids and glycerol. There are different functions for lipids in our bodies: Lipids can be used for longterm energy storage. Some lipids called phospholipids form biological membranes like the membranes around our cells. Form waterproof coverings Hormones and vitamins Phospholipids serve an extremely important function in our bodies, they form the cell membrane. The fatty acid chains are usually between 10 and 20 carbon atoms long. The fatty "tail" is non-polar (hydrophobic) while the carboxyl "head" is a little polar (hydrophillic). A cell as being surrounded by a flexible fence called the cell membrane. The cell membrane is composed of two layers, each composed of trillions of phospholipid molecules oriented in a special manner. Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm If each carbon atom in a lipid's fatty acid chains is joined to another carbon atom by a single bond, the lipid is said to be saturated. The term saturated is used because the fatty acids contain the maximum possible number of hydrogen atoms. If there is at least one carbon-carbon double bond in a fatty acid, the fatty acid is said to be unsaturated. The fatty acids in oils are mostly unsaturated, while those in fats are mostly saturated. oil Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm butter, margarine Proteins One of the four groups of organic compounds found in living things is proteins. Proteins are found in: Beef and pork Poultry Fish and shellfish Eggs Dairy products like cottage cheese and regular cheese Plant-based proteins like beans, nuts, and tofu Protein is an essential part of your diet -and your body. But, too much of a good thing can be bad for you. Most meats have fat as well as protein. So, excess protein from animal sources can mean excess calories and fat – which means a greater chance at gaining weight. Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm Functions of Various Proteins Antibodies - are specialized proteins involved in defending the body from antigens (foreign invaders). Contractile Proteins - are responsible for movement. Proteins such as actin and myosin are involved in muscle contraction and movement. Enzymes - are proteins that facilitate biochemical reactions. They are often referred to as catalysts because they speed up chemical reactions. Hormonal Proteins - are messenger proteins which help to coordinate certain bodily activities. Insulin regulates glucose metabolism by controlling the blood-sugar concentration. Structural Proteins - are fibrous and stringy and provide support. Keratin strengthen protective coverings such as hair, quills, feathers, horns, and beaks. Collagen and elastin provides support for connective tissues such as tendons and ligaments. Storage Proteins - store amino acids. Ovalbumin is found in egg whites and casein is a milk-based protein. Transport Proteins - are carrier proteins which move molecules from one place to another around the body. Hemoglobin transports oxygen through the blood. Primary Structure Secondary Structure Tertiary Structure Structure Proteins vary in structure as well as function. They are constructed from a set of 20 amino acids and have distinct three-dimensional shapes. The structure of a protein determines its function. For example, collagen that is found in hair and skin, has a supercoiled helical shape. It is long, stringy, strong, and resembles a rope. This structure is great for providing support. Hemoglobin on the other hand, is a globular protein that is folded and compact. Its spherical shape is useful for moving oxygen through blood vessels. Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm Quaternary Structure Nucleic acids The building blocks of nucleic acids are nucleotides. Nucleotides are made of three parts: a phosphate group, a sugar, and a nitrogen base. Nucleotides link together to form long strands. Function The main function of nucleic acids is to store and transmit genetic information and use that information to direct the synthesis of new protein. Functions of DNA (deoxyribonucleic acid): DNA is a permanent storage place for genetic information. DNA controls the synthesis of RNA (ribonucleic acid). The sequence of nitrogenous bases in DNA determines the protein development in new cells. Functions of RNA (ribonucleic acid): RNA transmits genetic information from DNA to the protein factories (ribosomes) in the cell. RNA also directs the synthesis of new proteins using the genetic information it has transported. Adapted from: https://www.msu.edu/~schaef86/macromolecules.htm