Carbohydrates are essential components of all living organisms. The basic units of all

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1 Kenneth O Rourke Biol 501 lesson plan Topic: I teach physical science and I am incorporating a biological application into my chemical bonding unit. I am putting it into two different sections. I am using the formation of a disaccharide to demonstrate how covalent bonding works in a biological process. I am also going to use the same reaction in a future lesson to demonstrate endothermic and exothermic reactions. Audience: 9 th grade physical science students (from low level to honors classes) Context: I am including my unit lesson plans to illustrate the progression of topics and the types of activities used for the lessons. I have highlighted the biological sections. Biology background research: Covalent bonding in sugars Carbohydrates are essential components of all living organisms. The basic units of all carbohydrates are the monosaccharides. They can be synthesized from simpler substances in a process called gluconeogenesis, but ultimately nearly all biological molecules are the products of photosynthesis. (An endothermic reaction that uses energy from the sun to make sugars from carbon dioxide and water) Polysaccharides consist of many covalently linked monosaccharide units and have molecular masses ranging into the millions of Daltons. One major role of carbohydrates is in energy reserves such as starch in plants and glycogen in animals. Although carbohydrates play a passive role in the cell they are essential elements in many if not most biological processes. I am using a simplified form of carbohydrates in this lesson, and it does not take into account all the varied configurations of carbohydrates in nature. Carbohydrates are made up of monosaccharides linked together into polysaccharide chains by a type of covalent bond known as a glycosidic bond. These glycosidic bonds are formed in a dehydration synthesis reaction. It is when one sugar gives up a hydrogen atom from a hydroxyl group

2 and the other sugar gives up the entire hydroxyl group. As H 2 O is formed an oxygen atom is left between two covalent bonds linking the two sugars. From: Monosaccharides can be linked together to form very long polysaccharide chains. Monosaccharides have a general molecular formula that is some multiple of CH 2 O. For example the formula for glucose is C 6 H 2 O it has the two trademarks of a sugar: a number of hydroxyl groups and a carboxyl group. Hydroxyl groups are made up of a hydrogen atom bonded to an oxygen atom. The oxygen is bonded to the carbon section of a molecule. Organic compounds containing a hydroxyl group are called alcohols. A carboxyl group is a carbon atom linked by a double bond to an oxygen atom. Fructose has the same chemical formula as glucose, but differs in its configuration. The hydroxyl group makes a sugar an alcohol and the carboxyl group makes it an aldehyde or keytone based on its location. Glucose is an aldehyde, and fructose is a keytone. Seemingly minor differences like this give isomers different properties, such as he ability to react

3 with other molecules. (isomers are two or more chemicals made from the same number and types of atoms, but have a different geometrical arrangement) In this case, the differences make fructose taste much sweeter than glucose. Polysaccharides are very versatile and can be formed into helixes as in starch and glycogen or in rod shapes as in cellulose. This rod shape links rods together through hydrogen bonds. Although they are made from similar molecules (mainly glucose) the hydrogen bonds between the rod shape of the cellulose makes it difficult to hydrolyzed by animals. Although cellulose is not absorbed nutritionally, it serves a purpose by providing our digestive tract with the fiber it needs to remain healthy. References: Figure taken from: Donald Voet, Judith Viot, Biochemistry 2 nd edition John Wiley & sons inc. NY,NY 1995 ISBN: Campbell, Reece, Mitchell, Taylor Biology Concepts and Connections 4 th edition Pearson Education inc. San Francisco, CA ISBN: x LESSON PLANS Chapter 19.1 Molecules and compounds Teacher: Kenneth O Rourke Subject: Physical Science Dates: to Time: Approx one week Topic: Chemical bonding Grade: 9 inclusion classroom Note: Intelligences- Linguistic, logical math, spatial, kinesthetic, musical, interpersonal, intrapersonal, naturalist.

4 Per. Standards- active learning, coherence, critical/creative thinking, real world connections, reflection, fosters understanding of content Objectives: Students will be able to: Relate chemical bonding to its placement on the periodic table Identify how chemical bonds form Explain the role of valence electrons in the bonding process Identify and diagram ionic and covalent bonds To relate and identify the types of bonds used in biological processes Discuss the importance of how each bond functions in biological processes Materials: Notebook, Textbook p , blackboard, computer, PowerPoint, overhead, TV, Internet, lab equipment, & calculator Vocabulary: Avogadro number, chemical bond, chemical formula, covalent bond, ionic bond, formula mass, octet rule, monatomic ion, polyatomic ion Organizational Structure: Traditional classroom setting, lab, group work Learning topic 1: Octet Rule 1) Review of valence electrons 2) Students calculate electron configuration 3) Atoms are in their most stable state when they have 8 electrons in their outermost energy level- Students will be able to explain the connection between the noble gasses and the octet rule Learning Topic 2: Periodic table and the octet rule 1) Valence electrons, orbitals, and periodic table worksheet 2) Periodic table & valence electron relative game 1) Students group elements according to valence electrons 2) Students investigate similarities and differences within the groups Learning topic3: Types of bonds 1) Bonding and molecule lab (atom building set useful for all activities) Atom building set is a model of an atom where protons, neutrons and electrons are placed in their proper places. Students can then use them to model the different kinds of chemical bonds. 2) Lewis dot diagrams a) PowerPoint b) Demonstration c) Student examples done on overhead 3) Ionic bonds a) Ionic bond PowerPoint b) Special properties of ionic bonds c) Ionic bond worksheet d) Ionic bond/lewis diagram worksheet

5 4) Covalent bonds a) Covalent bond PowerPoint b) Special properties of covalent bonds c) Covalent bond worksheet d) Covalent bond/lewis diagram worksheet Learning topic five: Chemical bonding in biological processes 1) Introduction to sugars- (Excerpts from a pdf document found at: ) Student handout (attached) In the first part of the lesson is to have an interactive lecture (in a POGIL style) by reading the document with the students, questioning them, and answering their questions. Have the students answer the first question, go over the correct answer identifying the different bonds in the molecule. Have students answer the second question, then get a good sample of answers from the class and come up with the best working answer for the question and allow students time to amend their answer. The final question students should answer on their own and hand in for you to grade. The questions are designed to see how well the students understand the concept of chemical bonding, and to see how well they can apply knowledge in a logical way to answer a question. Hints or cues may be needed to stimulate their thought process. 2) Identifying the chemical bonds in a monosaccharide and polysaccharides (covered in question one of the handout) 3) Benefits of the types of bonds and impact on cell function (covered in question 6 & 7 in the handout) 4) Students explain why covalent bonds are used in sugar formation, and why ionic bonds are not. (covered in question 6 & 7 in the handout) 5) Students build a long polysaccharide from atom building sets The atom building sets are given to each lab group to build a glucose molecule. The groups then link them into a polysaccharide chain. Each lab group needs to be supervised to insure they are making the right molecule. When the sugars are linked, make sure the water molecules are also formed. Point out to the students that the nature of covalent bonds makes it possible for living things to string large molecules together from smaller base units like bricks in a building. The size of the huge complex molecule model in your classroom should bring home the fact that very complex things are made up of simpler units, and can be understood when you see the pattern. Home Learning: Vocabulary, worksheets, lab reports, reading Assessment: 1) Question and answer sessions asking students to cite examples 2) Atom building models 3) Worksheets 4) Biological process handout 5) Quizzes 6) MOLP extra help session (one on one evaluation)

6 7) One thing learned and one thing you don t get. Write it down & hand in. This is helpful for the students that will not raise their hand to ask questions. You can get a good feeling as to what they understand and what confuses them about the concept. Reflection: Chapter 21 Types of Reactions Teacher: Kenneth O Rourke Subject: Physical Science Dates: to Time: 5 to 7 days Topic: Chem. reactions Grade: 9 inclusion classroom Note: Intelligences- Linguistic, logical math, spatial, kinesthetic, musical, interpersonal, intrapersonal, naturalist. Per. Standards- active learning, coherence, critical/creative thinking, real world connections, reflection, fosters understanding of content Objectives: Students will be able to: Classify reactions as: addition, Decomposition, Single displacement, Double displacement, and Combustion reactions. Predict the type of reaction and the products of that reaction from the reactants involved. Analyze and classify energy changes as exothermic and endothermic. Describe how energy changes applies to carbohydrate use and synthesis in biological systems Learning Topic one: Classifying reactions 1) Lab 20.1 Double replacement reaction 2) PowerPoint / Scion image interactive presentation on classifying reactions 3) Video on the different classes of reactions 4) Worksheet Learning Topic 2: Predicting products 1) PowerPoint / Scion Image tutorial 2) Worksheet Learning topic three: Energy in reactions 1) Lab 20.2 classifying reactions by the energy involved. (Endothermic/exothermic) 2) Cold pack demonstration- ammonium nitrate and water endothermic reaction 3) Combustion demonstration- natural gas and oxygen reaction 4) Examining the energy exchanges in carbohydrate production and decomposition Learning topic four: Energy exchanges in a biological application 1) Energy in the synthesis of a carbohydrate: Students take out their carbohydrates handout from lesson Students classify the synthesis of a disaccharide. Most should realize that energy is needed to link the sugars together. Have students

7 write the chemical equation for the synthesis of maltose. Make sure energy is included on the proper side of the equation. 2) Energy in a carbohydrate hydrolysis reaction. Students classify the hydrolysis of a disaccharide. Most should realize that energy is released to break the covalent bond that holds the sugars together. Have students write the chemical equation for the hydrolysis of maltose. Make sure energy is included on the proper side of the equation. 3) Draw a diagram of the energy flow in the synthesis and hydrolysis of a disaccharide. Students should show a representation of their knowledge of the processes and byproducts of the cycle. Home Learning: Vocabulary, worksheets, lab reports, reading Assessment: 8) Question and answer sessions asking students to cite examples 9) Biological process handout 10) Energy diagram 11) Worksheets 12) Quizzes 13) MOLP extra help session (one on one evaluation) Reflection: