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Unit Calendar Unit Calendar Unit Driving Question – How Does Food Provide My Body with Energy? Learning Set 1: How Do Food Molecules Compare to Each Other? 3 Class Periods Lesson 1 – Why Do I Lose Weight When I Exercise? Activity 1.1: What Happens in My Body When I Run around the School? Reading 1.1: What Happens in My Body When I Run around the School? Activity 1.2: How Can I Learn More about How Food Provides Energy to My Body? Reading 1.2: How Can I Learn More about How Food Provides Energy to My Body? 1–2 Class Periods Lesson 2 – What Do Plants Need to Grow? Activity 2.1: What Should I Consider When Designing Scientific Investigations? Activity 2.2: What Do Plants Need to Grow? Reading 2.1: What Do Plants Need to Grow? 2–3 Class Periods Lesson 3 – Do Different Foods Provide Different Amounts of Energy? Activity 3.1 Do Different Food Molecules Provide Different Amounts of Energy? Reading 3.1: Do Different Food Molecules Provide Different Amounts of Energy? Activity 3.2: Why Do Different Food Molecules Provide Different Amounts of Unit Calendar Unit Driving Question – How Does Food Provide My Body with Energy? Energy? Reading 3.2: Why Do Different Food Molecules Provide Different Amounts of Energy? Activity 3.3: How Much Do I Need to Exercise? Reading 3.3: How Much Do I Need to Exercise? Learning Set 2: What Do Organisms Do with Food? 2 Class Periods Lesson 4 – How Do Food Molecules Provide Organisms with Building Materials? Activity 4.1: How Does My Mouth Change Carbohydrates? Reading 4.1: How Does My Mouth Change Carbohydrates? 2 Class Periods Lesson 5 – How Are Food Molecules Built Up and Stored? Activity 5.1: Where Do Proteins Go When They Are Eaten? Reading 5.1: What Allows Organisms to Grow? Activity 5.2: Do Animals and Plants Store Food for Later? Reading 5.2A: Do Animals and Plants Store Food for Later? Reading 5.2B: Plants Also Store Food Molecules for Long Periods of Time Learning Set 3: Where Does the Energy in Food Come From? Unit Calendar Unit Driving Question – How Does Food Provide My Body with Energy? 2–3 Class Periods Lesson 6 – What Do Plants Need to Grow? Activity 6.1: What Do Plants Need to Grow? Reading 6.1: What Do Plants Need to Grow? 2–3 Class Periods Lesson 7 – How Do Plants Make Their Own Food? Activity 7.1: What Do Plants Produce in the Light? Reading 7.1: What Do Plants Produce in the Light? Activity 7.2: How Do I Know that Plants Use Carbon Dioxide? Reading 7.2: How Do I Know that Plants Use Carbon Dioxide? Activity 7.3: What Do Plants Produce in the Light? Learning Set 4: How Is Food Used for Energy? 2 Class Periods Lesson 8 – What Can Burning Food Teach Me about Food Providing Energy to My Body? Activity 8.1: What Does Food Need to Burn? Reading 8.1: What Can Burning Food Teach Me about Food Providing Energy to My Body? 4–5 Class Periods Lesson 9 – How Do Food Molecules Provide My Cells with Energy? Unit Calendar Unit Driving Question – How Does Food Provide My Body with Energy? Activity 9.1: Does a Reaction Similar to Burning Happen in My Cells? Reading 9.1: Does a Reaction Similar to Burning Happen in My Cells? Activity 9.2: How Do Food Molecules Provide Plants with Energy? Reading 9.2A: How Do Food Molecules Provide Plants with Energy? Reading 9.2B: Do Plants Give Off Carbon Dioxide? Activity 9.3: How Do Food Molecules Provide Energy? Reading 9.3: How Can I Tell that Food Molecules Provide My Cells with Energy? 3–4 Class Periods Lesson 10 – How Do Matter and Energy Move between Organisms? Activity 10.1: How Does Matter Transfer between Organisms? Reading 10.1: How Does Matter Transfer between Organisms? Activity 10.2: How Does Energy Move between Organisms? Reading 10.2: How Does Energy Flow through the Environment? Activity 10.3: How Can the Flow of Matter and Energy Change? Reading 10.3: What Else Is There to Learn about Energy? Prerequisite Content Knowledge Students will have gained prior knowledge from multiple science units from past years. Help students connect the following concepts to this unit. Matter is made of atoms. The arrangement and type of atoms in a substance determine its properties (IQWST IC1). During a chemical reaction, the atoms from the reactants rearrange to form the products. No matter is created or destroyed (IQWST IC2). Food provides the body with energy and building materials. Plants produce sugars and oxygen, need water and carbon dioxide, and use light energy. Organisms exist in ecosystems and their eating habits can be modeled in food webs (IQWST LS1). The respiratory and circulatory systems function to bring substances to and remove wastes from the cells. Enzymes digest food in the digestive system (IQWST LS2). Energy comes in many types and can be converted from one type to another. Energy cannot be created or destroyed (IQWST PS2). Tips for Investigations How Does Food Provide My Body with Energy? is a project-based unit. Each lesson carefully describes steps in the investigations, but the following general tips provide the long-term aspects for making solutions or caring for items in the lab. 1. Premake solutions—Several solutions are used throughout the unit. Most can be made once and stored for later use. The amount needed depends on the number of groups and classes. Specifications for solutions are given in the lessons in which they are used. These solutions are very forgiving. Exact measurements are not necessary. When putting the solutions out for the students, remember to carefully label them with their names: Albumin, Bromothymol blue, Amylase, and Sudan. 2. Elodea care—Elodea are relatively easy to culture. Start with a large bunch of elodea from an aquarium or fish store and place it in a large, clear container with gravel or stones. Cover it with tap water and place it in the light. Keep your elodea in a sunny window if possible. o When the algae (or the snails) start to take over the tank or the elodea is yellowing, it is time to clean the container. Pull out elodea and discard the yellowing sprigs. Remove as much algae as possible. Rinse tank and remove algae from tank sides and gravel. Replace elodea and refill the container with water. o A few times a year, fertilize the elodea by adding a small amount of fertilizer or a slow-release fertilizing “spike” to the water. (While plants can make their own food from carbon dioxide, they need a source of nitrogen to build proteins necessary for growth.) (This is needed in Lessons 9 and 11.) o Observations with healthy elodea that relate to the unit: When the container is in direct sunlight, oxygen bubbles will form. Leave the dissolved oxygen probe in the container for several days collecting data. Observe how the oxygen levels change in response to sunlight. 3. Hot water—Several investigations use hot water. It may be helpful to use a coffee pot or an electric teakettle to heat water in the classroom. 4. Light sources—A high-watt (100W or greater) bulb is likely to give faster results than a grow light bulb when working with indicators or probes to gather data about the elodea. IQWST Chemistry Safety Guidelines Students experiencing phenomena and engaging in scientific investigation are central to IQWST and to science in general. Inherent in “doing science” is using a vast array of materials. Students need guidance to learn and use safe, responsible laboratory procedures. A component of every science classroom includes informing students of safety precautions associated with doing investigations. At the start of every new investigation, students should be informed of the safety requirements associated with that activity. Each lesson in IQWST includes safety guidelines. The best way to have a safe science classroom is by being aware of all possible risks and hazards associated with doing investigations and continually reminding students that safety is paramount. Using the following safety rules, for teachers and students, will create a safe and engaging science laboratory. Teachers Read all chemical safety information on all chemicals you receive. Carefully read the safety guidelines that are included in each of the lessons. Although IQWST labs are designed to be safe, some investigations use chemicals that could be dangerous if not used as directed. Be familiar with all the possible hazards involved in each investigation. Wear goggles at all times to model safe and appropriate laboratory procedures. If students share goggles, the goggles should be cleaned and disinfected after each use. Have a first-aid kit and eye wash station available in the classroom. Portable eye wash stations are available for purchase. Direct students never to look directly into a test tube, flask, or beaker that contains compounds or solutions. If the material in the flask, beaker, or test tube is hot, it could boil/splash out. In some IQWST labs, students are directed to smell or “waft” the odor from a solution or compound. In these situations, it is safe to do so, but in general, students should never smell chemicals. Dispose of chemicals as directed on their labs or as described in the lesson. Never casually dispose of chemicals down a drain. IQWST lessons tell if chemicals should not be placed down the drain or if chemicals can be washed down the drain after diluting with water. Never put solids directly in the sink. When preparing solutions, always add the compound to water. Never add a small amount of water to a solid. Some chemicals generate heat when they dissolve and by adding small amounts of water to the chemicals, splattering could occur. Always pour acid into water and never water into a concentrated acid. Do not use mercury thermometers. Instead, use alcohol thermometers or electronic thermometers. Use plastic lab equipment, such as beakers and flasks, instead of glass lab equipment when possible. If glassware does break, do not have students clean it up. A teacher or custodian should pick it up and dispose of it in a container marked as broken glass. Provide sufficient time to complete an investigation; accidents may occur when students rush. Students Wear safety goggles as directed; do not remove during lab. Our eyes are precious and we need to protect them. Do not wear loose or flowing clothing, and roll up sleeves when doing an investigation. When using flames, tie back long hair. The science lab is not a place to comb hair or put on makeup. Do not eat or drink when performing an investigation. Never taste any chemicals used in the investigations. Never use any glass or plastic laboratory equipment as a drinking glass. Report to the teacher any injuries that occur, no matter how minor they seem to be. Read the labels on all chemicals carefully. Never mix chemicals just to see what will happen. Some combinations of chemicals can generate a great deal of heat. Such experimentation needs to be done under chemical hoods and under supervision. The best way to have a safe science classroom is to be preventive. Teachers and students need to be knowledgeable of the potential hazards and how to avoid them. Background Knowledge about Food The following section provides information regarding common nutritional terminology. Since these terms are encountered on food labels and in articles on health, dieting, and nutrition, it is beneficial to have accurate definitions in one place. Carbohydrates Carbohydrates can be simple sugars or complex sugars. Carbohydrates are used as fuel for the body. Simple sugars are also called monosaccharides. Examples of simple sugars are glucose (dextrose) and fructose (found in fruits). Monosaccharides are building blocks that can combine to form disaccharides and polysaccharides. Saccharide refers to a simple sugar. The prefixes refer to how many sugars are bonded together (mono = one, di = two, poly = three or more). Glucose is used as cellular energy. It is a product of photosynthesis and a reactant of cellular respiration. Both topics will be addressed within this unit. Two monosaccharides can combine to form a disaccharide. Some common disaccharides are sucrose (table sugar or sugar cane) and lactose (sugar found in milk). Polysaccharides are complex carbohydrates. Common polysaccharides are starch, glycogen, and cellulose. Starches are polymers of glucose and are found in plants to store excess glucose. Animals store glucose as glycogen (a polymer of glucose). Cellulose is a structural component of plants. Wood, cotton, and paper all contain high levels of cellulose. Proteins Proteins are large macromolecules composed of amino acids. There are 20 different types of amino acids, which can combine in many ways to form diverse proteins. Proteins do much of the work of the body—transporting molecules, protecting from the environment, creating structures, signaling via hormones, and metabolizing via enzymes. Fats The scientific name for fats is lipids. There are five types of fat, which differ in structure and function: free fatty acids, triglycerides, steroids, complex lipids such as phospholipids, and lipoproteins (a combination of a lipid and a protein). While all these lipids can be used as building materials, only triglycerides are used as a source of energy; therefore, only triglycerides are considered food. Fats are one way the body stores energy. One common property of all fats is that they do not dissolve in water. Triglycerides are made of a glycerol molecule connected to three fatty acids. The fatty acids are long chains of carbon and hydrogen atoms (natural fatty acids are 6– 22 carbon atoms in length), which end in a specific group—COOH. Oils and fats are both made of triglycerides and therefore share some properties (i.e., not soluble in water, greasy feel). Oils and fats have different properties (i.e., melting temperature) because of different lengths of the carbon chains and shapes of the molecules. The shape of the molecule depends on the number and type of double bonds in the fatty acid chains that make up the triglycerides. Triglycerides that have no double bonds in their fatty acid chains are called saturated fats. Saturated fats are found in animal products such as butter, cheese, and meat. Triglycerides that have double bonds in their fatty acid chains are called unsaturated fats. Because of the double bonds, some of the carbon atoms in the chain are connected to one hydrogen atom instead of two. This means that they have a C:H atom ratio that is smaller than the maximal one (they are not “saturated” with hydrogen atoms). Unsaturated fats are found in vegetable oils, nuts, and fish. Saturated fats stack easily because the fatty acid chains are straight, and most of them are solid at room temperature. Unsaturated fats have low melting points (most are liquids at room temperature) because they bend and kink where the double bonds occur; the double bonds make it difficult for the unsaturated fats to stack. Trans fats are a type of unsaturated fat, which means they have one or more double bonds between carbon atoms. The term transrefers to a specific configuration of the chains around the double bond. Small amounts of trans fats occur naturally, but most consumed trans fats are manufactured through a process called partial hydrogenation, which adds hydrogen atoms to some of the carbon atoms. Like saturated fats, trans fats are typically solids at room temperature. Some examples of foods with high levels of trans fats are vegetable shortening, margarine, and shortening. Trans fats are often referred to as “bad fat” because they raise cholesterol levels, and the metabolic processes that can break down fats work less efficiently on the unnatural configuration around the double bonds. Nutritionists recommend a diet rich with unsaturated fats (found in vegetable oils), compared to a diet rich in saturated fats. It is important to include fats in our diet because fats have important roles in the body. Fats are part of cell membranes, help regulate body temperature, are a component of hormones, dissolve vital vitamins that cannot be dissolved in water, and more. Most of the extra fat people and animals store is in special cells to be used later as a resource of energy. (This storage is responsible for weight gain.) However, some fats accumulate inside blood vessels (atherosclerosis), making the blood vessels narrower, often resulting in heart failure, high blood pressure, and other vascular diseases. Cholesterol is a lipid (insoluble in water) found in the body. It is a component of cells, specifically cell membranes and hormones, and is transported in blood. Typically, the body can make as much cholesterol as it needs, making it unnecessary to consume cholesterol through diet. The body regulates the amount of cholesterol present based on the amount consumed in your diet and what the body makes. Information on cholesterol levels is included on food labels in order to help regulate the amount of cholesterol consumed. High levels of cholesterol in the blood (hypercholesterolemia) are associated with cardiovascular disease. Cholesterol is carried through the body bound to a protein. Most likely the students are familiar with two types of proteins that carry cholesterol: LDL and HDL. Lowdensity lipoprotein (LDL) is often referred to as “bad cholesterol.” If too much LDL is present in the blood, it can build up and form a deposit on the walls of the arteries, limiting the blood flow within arteries. High-density lipoprotein (HDL) is often referred to as “good cholesterol” because it is believed that HDL carries excess LDL to the liver so the body can then eliminate excess cholesterol. Vitamins and Minerals There are other substances that have nutritional value and are important to the functioning of the body, such as vitamins and minerals. These are not considered to be food (scientifically), as they do not maintain both functions of food: provide energy and building materials. For example, calcium is a building block for bones and teeth but is not used for energy.