Name Group Members. Table 1 Observation (include details of what you observe)

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1 Name Group Members Macromolecules, Part 1 - PROTEINS There are four classes of macromolecules that are important to the function of all living things. These include carbohydrates, lipids, proteins and nucleic acids. In this laboratory experiment you will investigate the functions of three of these macromolecules. 1. PRE-LAB: Read the following passage and highlight important information about proteins Proteins are the macromolecule that do the work of living things. One important type of protein is the enzyme. Enzymes are catalysts that speed up chemical reactions. For example, the enzyme catalase breaks down hydrogen peroxide (H 2 O 2 ) into water (H 2 O) and oxygen (O 2 ). Catalase is found at high levels in liver. Enzymes are reusable, specific and their function is altered by their environment. A. What does it mean to be reusable? B. What does it mean to be specific? C. For the enzyme catalase, what is the substrate? What is the product? D. Draw a model of the steps of how an enzyme works in the box to the right. (p. 37 of INB) E. What environmental factors can alter the function of enzymes (look in your interactive notebook)? Part A: Guiding Question: Are enzymes reusable and specific? A. Your group s manager should get a small beaker of 3% hydrogen peroxide and a pipette. B. Fill up, about half-way, three wells in your spot plate with 3% Hydrogen Peroxide. C. Place a piece of liver in the first well. Note what happens in your data chart below (table 1). D. Use your forceps to move the liver to the second well and observe what happens. E. Use your forceps to move the liver to the third well and observe what happens. Table 1 Observation (include details of what you observe) 1. Liver in first well of H 2 O 2 (hydrogen peroxide) 2. Liver in second well of H 2 O 2 3. Liver in third well of H 2 O 2 Liver contains the enzyme catalase which breaks down H 2 O 2 into H 2 O and O 2. What did you observe that indicates that this reaction took place? What property of enzymes did this experiment demonstrate (from your pre-lab reading)? Part B: A. Your group s manager should get a small beaker of 3% sodium chloride and a small container of water. B. Fill up, about half-way, three wells in your spot plate with each of the solutions (3% Hydrogen Peroxide, 3% sodium chloride and 3% tap water). Make sure you know which solution is in which well. C. Place a piece of liver in each well and note what happens in your data chart on the back side of this page (table 2). 1

2 Part B continued Table 2 Observations (include details of what you observe) 1. Liver in 3% H 2 O 2 2. Liver in sodium chloride 3. Liver in tap water Did you observe the same result when liver was put in all three of the solutions? What property of enzymes did this experiment demonstrate and why do you think that? Part C: Guiding Question: Does temperature affect the activity of enzymes? A. Your group s manager should get a piece of room temperature liver, of ice cold liver and of boiled liver B. Fill up, about half-way, three wells in your spot plate with 3% Hydrogen Peroxide. C. Place a piece of liver from each temperature into a separate well and note what happens in your data chart below. Table 3 Observations (include details of what you observe) 1. Cold liver in 3% H 2 O 2 2. Room temperature liver in 3% H 2 O 2 3. Boiled liver in 3% H 2 O 2 Did the temperature of the liver change what happened when it was put in hydrogen peroxide? Describe the differences you observed. 3. CONCLUSIONS (use additional paper if needed) Make a claim as to whether enzymes are reusable and specific (based on the guiding question for part A). Support your claim with evidence from your investigation (table 1 and 2), from the pre-lab reading and from your interactive notebook (key words to use incude: enzyme, active site, substrate, product): Make a claim as to whether enzymes are affected by temperature (based on guiding question from part C). Support your claim with evidence from your investigation (data table 3) and from your notes in your interactive notebook: 2

3 Name Group Members Macromolecules, Part 2 - CARBOHYDRATES 1. PRE-LAB: Read the following passage and highlight important information about Carbohydrates Carbohydrates are used by the living things for energy and for structural support in cell walls of plants and exoskeletons of insects and crustaceans. They are made of smaller subunits (monomers) called monosaccharides. Monosaccharides or simple sugars include glucose, galactose, and fructose. These simple sugars combine to make disaccharides (double sugars like sucrose) and polysaccharides (long chains like cellulose, chitin, and glycogen). Yeasts are tiny, microscopic organisms or microorganisms that are actually a type of fungus. These little critters might sound strange and different, but people have been using them for thousands of years to make bread rise. How does this work? It has to do with the metabolism of the yeasts, or, in other words, what they eat and what they turn that food into. Yeasts feed on sugars and they turn this food into energy and release carbon dioxide gas as a result. This process is known as fermentation. A. What are examples of foods that contain many carbohydrates? B. What is a monomer? What is an example of a monomer of carbohydrates? C. How do yeasts get energy? D. What is released when yeast perform fermentation? E. Draw a model of a complex carbohydrate to the right, label the monomer. (p. 168 of textbook) Guiding question: What food source does yeast use to produce energy? A. Your group s manager should obtain 10 ml of each of the following solutions in 4 separate test tubes: 10% glucose solution, tap water, 10% starch solution, oil. In addition, your group s manager should get a small amount of yeast. B. Place a small amount of yeast into each of the test tubes. Cover and shake gently to mix. C. Wait 10 minutes and then observe your results. While waiting start on Part 3 of the lab (LIPIDS) (other side of this page) Table 4 Observations (include details of what you see) 1. Yeast in glucose solution 2. Yeast in water 3. Yeast in starch solution 4. Yeast in oil What is the food source yeast use to obtain energy (in a process called fermentation)? What did you observe (and in which test tube) to indicate that fermentation was occurring? What caused this? 3

4 Macromolecules, Part 3 - LIPIDS 1. PRE-LAB: Read the following passage and highlight important information about Lipids Lipids are large, nonpolar (won't dissolve in water) molecules. Lipids are also known as fats and are used as long term energy storage, for protection and for insulation. Lipids also serve as waxy coverings (cuticle) on plants, pigments (chlorophyll), and steroids. Lipids have more carbon and hydrogen atoms than oxygen atoms. Fats are made of a glycerol (alcohol) and three fatty acid chains. This subunit is called a triglyceride. A special type of lipid called phospholipids help make up the cell membrane. Two layers of these phospholipids make up the membrane. Phospholipids have a "water-loving" hydrophilic head and two "waterfearing" hydrophobic tails. The principal component of egg yolks is phospholipids, which are amphiphilic, or are composed of polar and nonpolar ends. A. What does nonpolar mean? B. What are the uses of lipids? C. What are the subunits of fats called? What are they made of? D. What type of lipid makes up the cell membrane? E. Draw and label a phospholipid (p. 188 of your textbook). How do phospholipids rearrange themselves on the surface of the water (lipid bilayer)? Sketch your result in the box below. Label the hydrophobic and hydrophilic parts of the lipid bilayer. Phospholipid Phospholipid Bilayer Guiding Question: How does the structure of phospholipids influence how they assemble in water/oil? A. Your group s manager should obtain oil and water and plastic wrap. B. Mix about 5 ml of oil to 20 ml of water in a beaker. Cover then shake for 2 seconds. C. Wait 5 minutes then record observation. (while waiting, return to your yeast experiment and record your results in your data table. After 5 minutes record your observations in table 5. D. Your group s manager should obtain a 1 ml syringe filled with egg yolk E. Add a small drop of egg yolk to the oil water mixture (be careful to add just one or two drops). Record your observation in table 5 F. Shake the mixture gently for 2 seconds and then record your results in table 5 Table 5 Observations (include details of what you see) 1. Oil and water mixture 2. Egg yolk in water/oil 3. Egg yolk in water/oil after shaking On the next page, draw a model, using your diagram of phospholipids of what happened when you put the egg yolk in the oil/water mixture 4

5 Phospholipid model of egg yolk in oil/water 3. CONCLUSIONS for Carbohydrates and Lipids (part 2 and part 3) A. Write a claim that explains what carbohydrate yeast uses as a food source and explain if yeast uses a monomer or polymer (see guiding question for part 2). Support your claim with evidence from your experiment (data table 4) as well as your the pre-lab reading, text book and interactive notebook notes (use the following words: carbohydrate, monosaccharide, monomer, polymer, fermentation, carbon dioxide). B. Write a claim that explains how the structure of phospholipids allows them to form a sphere in water (see guiding question for part 3). Support your claim with evidence from your experiment (data table 5) as well as from your pre-lab reading, interactive notebook and text book. 5