table of contents - bellefonte area school district · table of contents unit overview ... amylase...
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Table of Contents
Unit Overview ............................................................................ 3-6
Teacher's Guide for Implementation.......................................... 7-10
Student Data and Answer Booklet ............................................. 11-56
Student Resource Booklet .......................................................... 57-58
Assessment and Evaluation Tools.............................................. 59-69
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Unit Overview
Title of Unit: Pasta Power Recommended Grade Levels: 10th Time Frame: Nine hours Organizing Theme: Systems and Interactions Integration Model: Integrated Pennsylvania Academic Standards Addressed in Unit: Science and Technology: Reading, Writing, Speaking and Listening; and Mathematics
Academic Standard
Standard Category
Standard Statement
Content Descriptors
Performance Tasks and Associated
Learning Activities
Science and Technology
3.3.10 Biological Sciences
B. Explain the chemical and structural basis of living organisms.
Describe the relationship between the structure of organic molecules and the function they serve in living organisms.
1. Build a polysaccharide from monosaccharides using 3D models.
2. Draw the interaction of an enzyme and its substrate.
B. Explain the chemical and structural basis of living organisms.
Explain cell functions in terms of chemical reactions and energy changes.
1. Perform dehydration synthesis and hydrolysis of a polysaccharide.
2. Write and balance chemical equations for each type of reaction.
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Academic Standard
Standard Category
Standard Statement
Content Descriptors
Performance Tasks and Associated Learning Activities
Describe the physical properties of elements and compounds as they reflect their structure.
1. Taste and compare the degree of sweetness between monosaccharide isomers and a polysaccharide.
3.4.10. Physical Science, Chemistry and Physics
A. Explain concepts about the structure and properties of matter.
Describe various types of chemical reactions in terms of the law of conservation of matter and energy.
1. Balance equations for dehydration synthesis and hydrolysis.
3.2.10. Inquiry and Design
C. Apply the elements of scientific research to solve problems.
Conduct a multiple step experiment.
3.1.10. Unifying Themes of Science
B. Describe concepts of models as a way to predict and understand science and technology.
Examine the advantages of using models to demonstrate processes and outcomes.
1. Perform Salivary Amylase Lab.
Science and Technology
3.1.10. Unifying Themes of Science
C. Apply patterns as repeated processes or recurring elements in science and technology
Examine and describe recurring patterns that form the basis of biological classification, chemical periodicity, geological order and astronomical order.
1. Perform condensation and hydrolysis reactions using 3D models.
Reading, Writing, Speaking and Listening
1.2.11. Reading Critically in All Content Areas
A. Read and understand essential content of informational texts and documents in all academic areas.
Distinguish between essential and nonessential information across a variety of sources, identifying the use of proper references or authorities and propaganda techniques where present.
1. Research carbohydrate metabolism using the Internet and library.
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Academic Standard
Standard Category
Standard Statement
Content Descriptors
Performance Tasks and Associated
Learning Activities 1.4.11. Types of Writing
B. Write complex informational pieces (e.g., research papers, analyses, evaluations, essays).
Use precise language and specific detail.
1. Write an explanation of carbohydrate metabolism.
B. Write using well-developed content appropriate for the topic.
Write fully developed paragraphs that have details and information specific to the topic and relevant to the focus.
1. Write an explanation of carbohydrate metabolism.
C. Write with controlled and/or subtle organization.
Sustain a logical order throughout the piece.
1. Write an explanation of carbohydrate metabolism.
1.5.11. Quality of Writing
F. Edit writing using the conventions of language.
All 1. Write an explanation of carbohydrate metabolism.
Reading, Writing, Speaking and Listening
1.6.11 Speaking and Listening
F. Use media for learning purposes.
Use various forms of the media to elicit information, to make a presentation and to complete class assignments.
1. Research carbohydrate metabolism.
Mathematics 2.8.11 Algebra and Functions
A. Analyze a given set of data for the existence of a pattern and represent the pattern algebraically and graphically.
N/A 1. Derive formulas for monosaccharides, disaccharides and polysaccharides.
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Academic Standard
Standard Category
Standard Statement
Content Descriptors
Performance Tasks and Associated
Learning Activities 2.8.11 Algebra and Functions
C. Use patterns, sequences and series to solve routine and non-routine problems.
N/A 1. Predict the formula of a polysaccharide.
Mathematics
2.9.11. Geometry
J. Analyze figures in terms of the kinds of symmetries they have.
N/A 1. Compare structural formulas of monosaccharide isomers.
Brief description of unit: In this unit, students discover the fundamental process of polymerization in the metabolism of organic compounds. By physically manipulating three-dimensional molecular models, students are actively engaged, individually and as a class, in a very abstract topic. The unit is specific to carbohydrates, which is usually the first group of biomolecules studied. Students derive formulas for three classes of carbohydrates, distinguish between structural and molecular formulas and compare the structure, taste and use of isomers in consumer products. Students investigate the role of enzymes in metabolism and perform the anabolic and catabolic reactions of dehydration synthesis and hydrolysis using the three dimensional models. Using their knowledge of biochemistry, students then research, write and present a speech on carbohydrate-loading to student athletes. The purpose of the presentation is to convince athletes of the importance of the annual spaghetti dinner before the biggest track meet of the year.
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Teacher’s Guide for Implementation of Task
Time Allotment: Nine hours for all activities, including Web searches and writing time. Student Grouping: Activities include working in pairs and individually. Two model-building activities require the cooperation of the entire class. Materials/Resources Needed: For a class of 24 students: • 100 eight ounce plastic cups • near saturated solutions of glucose, fructose, sucrose and starch (10 ml. per student) • models (Chemistry of Carbohydrates Kit by Lab Aids, Carolina Biological Supply
Company,1999, catalogue #AA-84-0254) • assorted sports drinks (Gatorade, Powerade, etc.) • one hot water bath • test tubes, 6 per group of 2 • test tube racks and holders • iodine • Benedict's solution • Safety goggles Teacher Preparation Prior to Unit: Students should have a basic understanding of atomic structure and atomic bonding. The teacher should assemble the models first in order to anticipate and recognize potential student difficulties and common mistakes.
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Implementation of Specific Activities:
The initial expense of the models is well worth the enthusiasm generated and the visual foundation students develop for future topics in molecular biology. Model building engages students of all levels. Leave assembled carbohydrate models around the room for comparison as lipids, proteins and nucleic acids are taught.
Web Sites for Teacher Background Information: 1. http://people.ne.mediaone.net/jkimball/BiologyPages/C/Carbohydrates.html 2. http://wwwnhmccd.edu/public/nsci/bio/dehydrat/dehydrat.html 3. http://www.eufic.org/foodtoday/eng/ft11/foodwatch.html 4. http://www.mayohealth.org/mayo/9903/htm/carbohyd.htm 5. http://kauai.cudenver.edu:3010/0/nutrition.dir/salva.html 6. http://kauai.cudenver.edu:3010/0/nutrition.dir/carbos.html 7. http://www.cafecreosote.com/Reference/PastaPage.html 8. http://kauai.cudenver.edu:3010/0/nutrition.dir/carbint.html 9. http://ww.fac.swt.edu/BIO_1410/BioChemSite/Docs/Dehydration.html 10. http://www.bodywise.org/carbo.html 11. http://www.sportnutrition.com/scarru.html 12. http://www.propelsports.com/home.html 13. http://www.chemfinder.com/cgi-win/cfserver.exe/ 14. http://naturalsciences.sdsu.edu/classes/lab2/carbohydrates.htm Activities 2 and 7 are adapted from Laboratory Biology, Investigating Living Systems. (1986). Albert Kaskel, Paul Hummer, Jr., James E. Kennedy, and Raymond F. Oram. Charles E. Merrill Publishing Company, Columbus, Ohio.
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Overview of Activities
Activity 1 Prior to implementing this activity, prepare near saturated solutions of glucose, fructose, sucrose and starch. You will need 10ml per student. You will also need a total of eight (8) cups for each team of students. You will need two (2) cups per student. Each student will have one cup filled with warm water. The second cup will serve as a waste-water receptacle. You will need an additional four (4) empty cups for students to fill with the prepared solutions. Activity 1d requires students to have Internet access. You may choose to have students complete this section at home or in the library. Activity 2 Involves students in examining the structural formulas for glucose, fructose and galactose. You may wish to have copies of these formulas on overheads for whole group discussion. You may also want to have examples of the structural and molecular formulas of glucose or fructose on an overhead to enhance discussion. Activity 3 Requires students to examine a variety of sports drinks from the grocery store. You may wish to have some examples to use at various times of the day. This would benefit students who cannot easily obtain the sports drinks or visit a grocery store in the alloted time. Activity 4 Requires students to construct molecular models of monosaccharides. This is completed using packaged materials from the Chemistry of Carbohydrates Kits. This activity may be adjusted depending upon your individual resources and supplies. Activities 5 & 6 Requires students to continue to use models that represent an open chain glucose molecule. Activity 7 Remind students prior to implementing this activity that eating or drinking in the lab is not permissible. They should discard and candy or gum and rinse their mouths thoroughly prior to the experiment.
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Materials needed for Activity 7 include: • hot plate • Pyrex beaker • water • iodine solution • starch solution • Benedict’s solution • dropper • glass marking pencil • saliva (provided by one student on the team) • test tubes • test tube holder Activities 8 & 9 These activities deal with the digestion of starch and the absorption of glucose into the blood stream. Internet access is needed for research.
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Student Data and Answer Booklet
Name: Date:
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Pasta Power
Engagement You are the student athletic trainer for your school district. The track coach knows you will be studying carbohydrate loading in your biology class and has asked you to explain to the track team why every year he hosts a spaghetti dinner for the team the night before the meet with your arch rival school. The coach is convinced that your explanation about the relationship between the food they consume and their performance at the meet will add to the team determination, spirit and enthusiasm. However, both you and the coach know your presentation must be clear, detailed and persuasive to motivate all team members to attend the spaghetti dinner. To help you with this assignment, the attached unit called Pasta Power has been designed for you.
Exploration Activity 1: “Go for the Gusto” Every day of your life, without thinking about it, your senses of taste and smell are constantly monitoring your environment. You are collecting data from the air around you and through the things you put into your mouth. In fact, the two senses work together to analyze smells. Have you ever noticed that when you have a cold, you cannot taste food as well? Here are two websites you might want to visit about tasting and smelling. http://www.blkbox.com/~rdevere/tsdc/index.html http://mayohealth.org/mayo/9707/htm/taste.htm
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Important Information Both the senses of taste (gustation) and smell (olfaction) are necessary for any organism to respond to its environment, which is one of the main characteristics of living livings. Gustation and olfaction are possible because cells on the tongue and in the nasal cavity recognize and respond to molecules that are dissolved in solution, whether saliva in the mouth or mucus in the nasal cavity. This molecular recognition is called chemoreception. In the activity “Go for the Gusto,” you will investigate how the structure or shape of a molecule determines its properties such as taste. Activity 1a In this activity, you will do a blind taste-test of four carbohydrate solutions. Procedures: As a team of two: • Name four foods you eat that you think are carbohydrates.
1. 2. 3. 4. As an individual: • Obtain two cups that you will use to rinse your mouth throughout the experiment:
• one cup should be filled with water at room temperature, and • the second cup will be the waste water receptacle.
Activity 1b Considering the foods you have chosen in Activity 1a and the four taste categories (sweet, sour, salty, bitter), how do you predict carbohydrate solutions will taste? Why did you predict this?
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Exploration Activity 1c Designate you and your partner as Taster 1 and Taster 2. As an individual: • You will now taste four carbohydrate solutions and rate each for sweetness on a scale of 0
(not sweet) to 3 (very sweet). Record your data in the table below. Procedures:
1. Obtain 4 cups and label them to correspond to the labels on the solutions your teacher has prepared.
2. Measure 10 ml of each carbohydrate solution into the appropriately labeled cup, and
bring them to your lab station.
3. At your lab station, rinse your mouth with water for 15 seconds to remove any candy or gum residue, and gently spit into the waste cup. You may swallow the water if you prefer.
4. At your lab station, swirl the first solution (all 10 ml) in your mouth for 15 seconds. Then
spit the solution into the waste cup. Caution: When finished, all solutions must be disposed of into a container designated by the teacher.
5. Rate the sweetness of the solution in the data table on a scale of 0 (not sweet) to 3 (very
sweet).
6. Repeat Steps 3 – 5 for each of the four solutions. Be sure to include Step 3 between tastings!
Relative Sweetness of Unknown Carbohydrate Solutions
Trial 1 Trial 2 Taster 1 Taster 2 Taster 1 Taster 2 Solution ______ _______ _______ _______ _______ Solution ______ _______ _______ _______ _______ Solution ______ _______ _______ _______ _______ Solution ______ _______ _______ _______ _______
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As a team:
• Because the data is relative sweetness, you will run a second trial blindfolded. Procedures:
1. Refill the labeled cups with the appropriate solutions as in Step 2 above.
2. Place a blindfold on Taster 1.
3. The partner will guide the taster through steps 3 – 6 and record the relative sweetness on the same data table under Trial 2. To be a blind test, the taster must not know which solution is being tasted.
4. Roles should then be reversed and the experiment repeated as Trial 2 for Taster 2.
5. Review the data you have collected, and rank the solutions in order of sweetness.
6. To interpret scientific data easily, scientists compile “pictures” of the data in the form of
a graph. As a team, decide what type of graph would most clearly represent your data, and create it in the space below.
7. Now you can draw your conclusion about which solutions are sweetest. List them below
from least sweet to most sweet. Least ____________, ______________, _______________, ______________Most
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Exploration Activity 1d Try some of the websites in your Resource Booklet to see what you can find out about taste reception. Is taste subjective, or both?
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Exploration Activity 2: "Molecules Have Bodies, Too"
There are three different groups of carbohydrates. They are called monosaccharides, disaccharides and polysaccharides. Saccharide means sugar. A single molecule sugar is called a monosaccharide. The prefix “mono” means one. Examine the structural formulas of the three monosaccharides below and answer questions 2a to 2g.
Activity 2a What patterns do you detect among the three structural formulas for the monosaccharides shown
above?
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Activity 2b How many atoms of carbon are present in a molecule of Glucose _______? Fructose _______? Galactose _______? Activity 2c Add subscripts to the following to indicate the proper molecular formula. Glucose C_ H_ O_ Fructose C_ H_ O_ Galactose C_ H_ O_ Activity 2d What is the ratio of hydrogen to oxygen atoms in a molecule of Glucose _____? Fructose _____? Galactose _____? Why do you think this is the case? Activity 2e What is the molecular formula for water? _______ Are there two times as many hydrogen atoms as oxygen atoms in a molecule of water? Yes No
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Activity 2f Mathematically reduce the molecular formula for a monosaccharide as you derived it in step 2c.
C_ H_ O_
By looking at this reduced formula and examining word roots, explain why "carbo-hydrate" is an appropriate term to classify this group of compounds. Activity 2g Compare the structural formulas of glucose and fructose above. Are they exactly the same shape? ______ Are they both monosaccharides? ______ Circle the specific parts of the molecules where they differ. Activity 2h What does a structural formula tell you that a molecular formula does not?
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Activity 2i Based upon the observations you have made, why do you think glucose and fructose taste different? Important Information Molecules having the same molecular formula but different structural formulas are called isomers of one another. Isomers have different physical and chemical properties. Exploration Activity 3: Consumer Product Analysis Food companies develop products to meet the needs of the consumer and make a profit at the same time. In this activity, you will examine a variety of sport drinks from the grocery store and determine the relative frequency that a specific monosaccharide appears.
Activity 3a Prepare a data table in the space provided to record your observations. Include headings for the name of the product and the sweetener(s) used.
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Explanation Activity 3b Ingredients are listed on food labels in order of their concentration from highest to lowest. Examine the ingredient labels of the drinks provided, and record the name of the product and the first sweetener listed on the label in the table above. Activity 3c Which monosaccharide was used most frequently? __________________ Based on the business person’s motivation (profit and consumer pleasure), why do you think a food processor would choose this isomer over another to sweeten the product? Activity 3d A drug developed to help pregnant women overcome morning sickness was later discovered to be the cause of grotesque limb deformities in newborns whose mothers had taken the drug. Research the drug thalidomide, and write a one-paragraph news release from the developer of the drug to the pharmaceutical industry warning how this could happen in the manufacture of other drugs.
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Exploration Activity 4: A Model is Worth a Thousand Pictures As a team of two: 1. Obtain a molecular parts packet from your teacher. You will use the parts to construct
molecular models of monosaccharides.
2. Carefully empty the contents of the packet onto your lab desk so as not to lose any parts.
• Separate the pieces of plastic tubing. Each of these represents a chemical bond. • Separate the remaining parts by color. Each color represents a different chemical
element: black is carbon, white is hydrogen, red is oxygen. • The number of pegs on each part represents the number of bonds an atom of that element
forms with another atom.
Activity 4a How many bonds does carbon form? _____
How many bonds does hydrogen form? _____
How many bonds does oxygen form? _____
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Figure 1 below is a line structural formula for the monosaccharide glucose.
The lines represent the covalent chemical bonds (each bond results from a pair of shared electrons) between the atoms.
• Note that the molecule has a “backbone” of carbon atoms. This will be the first step in
building your model of glucose. As an individual: • construct a straight chain by bonding six carbon atoms (black). Attach the carbons using the
bonds (pieces of plastic tubing) in the kit. Activity 4b Why is making the chain straight so difficult?
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Activity 4c As compared to the line drawing in Figure 1, how does the model change your concept of the straight chain molecule? Procedures: 1. Using paper tape, number the carbon atoms from 1 through 6 as shown for reference. 2. Attach two bonds to carbon number one in your chain. 3. Attach the opposite ends of the same two bonds to one oxygen atom (red). You have just
formed a double bond between carbon number one and oxygen. 4. Rest the chain on your desk. Important Information Sometimes groups of atoms attach to the chain as if they were only one atom. These groups of atoms may serve as functional groups because they are the parts of the molecule that change in a chemical reaction with another molecule. The hydroxyl group is composed of one hydrogen atom and one oxygen atom. Explanation
Activity 4d Refer to Figure 1. How many hydroxyl groups do you need to construct glucose? • Construct the hydroxyl groups by attaching a hydrogen atom (white) to an oxygen atom
using one bond.
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Activity 4e Can hydrogen form any more bonds? ________ Can oxygen form any more bonds? ________ • Following Figure 1, bond the -OH groups to the carbon chain in the positions indicated. • Now, attach hydrogen atoms to the carbon chain at the remaining available bonding sites. Note: An accurate molecular model is essential to the remainder of this activity. Looking at your model, answer the following questions. Activity 4f Does each atom have the correct number of complete bonds formed (every peg is bonded to the peg of another atom)? ______ Activity 4g How many carbon atoms are present? _____ How many hydrogen atoms are present? _____ How many oxygen atoms are present? _____ The molecular formula for glucose is _________________. Exploration Activity 5, Part A: Chains to Rings The model you have completed represents an open chain glucose molecule. Crystalline glucose occurs in this form; however, glucose in biological systems usually assumes a cyclic or ring form when the ends of the molecule are brought together.
To demonstrate formation of the cyclic structure of glucose, you will perform the reaction in which the double-bonded oxygen (position 1) reacts with the -OH group (position 5) in the following manner:
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Procedures: 1. Carefully twist the bonds of the carbon chain to bring together carbon atoms 1 and 5 as
shown in the line diagram below.
2. Detach the oxygen atom from carbon 1 by removing one peg of the oxygen atom from the
bond. The bond (plastic connector) will be left attached to carbon 1. 3. Remove the hydrogen atom from the -OH (hydroxyl) group of carbon 5, and bond it to the
oxygen of carbon 1. 4. Bond the oxygen of carbon 5 to carbon 1 to form the ring as shown in the line diagram
below.
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5. Molecules will assume a formation that puts the least amount of strain on the bonds. If any
bonds in your molecule are "stressed" (bent), rotate the bonds between atoms until the molecule is stable.
6. Refer to the structural formula of glucose in Activity 2, and note the bolder lines representing
some of the carbon-to-carbon bonds within the ring. Using this structural formula and with your model in hand, answer the following questions:
Activity 5a What do the bold lines in the structural formula tell the reader about the three-dimensional shape of the glucose ring structure? Activity 5b What is the molecular formula of your molecule? C_ H_ O_ Activity 5c What is the ratio of hydrogen to oxygen in this molecule? _________ Activity 5d To what class of compounds does a molecule with this ratio belong?
______________________________ Activity 5e Because there is only one ring, glucose is classified as a ______- saccharide.
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Activity 5f How many carbon atoms are in the ring part of the molecule? ______ Activity 5g How many carbon atoms are above or below the ring? ______ Exploration Part B. Isomers Molecules with the same molecular formula but different structural formulas are called isomers of one another. Recall from Activity 2 that there are three isomers with the formula C6H1206. Isomers such as glucose and fructose have different physical and chemical properties. You will now convert glucose to fructose. This step should be performed by only one team member. One of the glucose rings must be preserved for a future step. The partner should read the directions while the other person performs the task. Procedures: 1. Remove the hydrogen atom from carbon 2. Leave the bond attached to the carbon. Put the
hydrogen atom on your desk. 2. Disconnect the oxygen atom from carbon 1 (leaving the bond attached to carbon 1), and bond
the oxygen to carbon 2. 3. Connect the hydrogen removed from carbon 2 to carbon 1. 4. "De-stress" your molecule by twisting the bonds so they are not bent and the molecule is
stable. 5. Compare your molecule to the structural formula for fructose in Activity 2, and answer the
following questions: Activity 5h What is the formula for fructose? C_H_O_
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Activity 5i What is the ratio of hydrogen to oxygen in this molecule? _______ Explanation
Activity 5j To what class of compounds does a molecule with this ratio belong?
_____________________________
Activity 5k Because there is only one ring, fructose is classified as a ______- saccharide. Activity 5l How many carbon atoms are in the ring part of the molecule? ____ Activity 5m How many carbon atoms are above or below the ring? ______ Activity 5n Explain why glucose and fructose are isomers of one another.
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Activity 5o What property of glucose and fructose did you explore that is different because of the difference in structure between these molecules?
DO NOT DISMANTLE YOUR MODELS. THEY ARE NEEDED FOR THE NEXT ACTIVITY.
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Exploration Activity 6: Monomers to Polymers Important Information Plants produce glucose in the process of photosynthesis. They use some of the glucose to grow and reproduce. The remaining glucose is stored as a polysaccharide called starch. "Poly-" means many. In this activity, you and your classmates will construct a polysaccharide from your monosaccharides. Part A. Disaccharides
Two monosaccharide sugar molecules can join chemically to form a larger carbohydrate molecule called a double sugar, or disaccharide. The prefix di- means two. By chemically joining a glucose molecule with a fructose molecule, a double sugar called sucrose is produced. Sucrose is common table sugar. In order to join your monosaccharides, there must be a place to attach them. Recall that your monosaccharide model was accurate only if each atom had formed bonds with another atom at each available site (peg).
Looking at your models, predict what you think must be done to free up bonding sites so that the monosaccharides can be chemically joined together. Write your answer below. Important Information Chemical reactions involve molecules called reactants interacting in such a way that bonds are disrupted and reformed resulting in the formation of new, different molecules called products. The parts of molecules involved in chemical reactions are called functional groups.
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Activity 6a Refer back to Activity 4 where you assembled six functional groups on glucose. What is the functional group in a carbohydrate? _________ With your partner, you will perform a chemical reaction between your glucose and fructose models that will result in the formation of disaccharide, sucrose. Procedures: 1. Each person should pick up the model he/she made of glucose or fructose. 2. Bring together the position 1 -OH group of glucose and the position 2 -OH group of fructose.
Use the diagram below for reference.
3. Remove the entire -OH group (including the bond attaching the group to carbon) from
glucose. Hold the -OH group in your hand. 4. Remove the hydrogen atom from the hydroxyl group of carbon 2 in fructose (leaving the
bond attached to oxygen). 5. Join together the atoms you have removed from the monosaccharide sugars.
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Activity 6b What is the molecular formula of this molecule? H_ O What is its common name? Exploration Water is a product of the reaction between two monosaccharides. The other product is formed by connecting the sugars at the bonding sites made available by the removal of water. Important Information Bond the oxygen at carbon 2 of fructose (remaining from the disrupted hydroxyl group) to carbon 1 of glucose. You will see two rings joined by an oxygen (red) "bridge." The molecule you have formed is the disaccharide or double sugar sucrose. Sucrose is common table sugar. Activity 6c Write the molecular formula for sucrose by 1. first adding together the molecular formulas for glucose and fructose C_ H_ O_ + C_ H_ O_ ___________ Total C_ H_ O_ 2. and then subtracting H20 that you removed.
Total C_H_O_
- H20 Formula C_ H_ O_ The molecular formula of sucrose is ___________________
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Activity 6d What is the ratio of hydrogen to oxygen in this molecule? _________ Activity 6e To what class of compounds does a molecule with this ratio belong? ____________________________________ Activity 6f Because there are two rings, sucrose is called a _____-saccharide. Congratulations! You have performed a chemical reaction. Activity 6g What are the names of the reactants in this chemical reaction? (What molecules did you start with?)
_______________________________________________ What are the names of the products of this reaction? (What molecules did you end up with?) _______________________________________________ Important Information A chemical equation is a summary sentence for a chemical reaction. Reactants yield products. "Yield" is written as an arrow. (Note that reactants do not “equal” products because reactants and products are not the same.) Using the names of the compounds, write the equation for the reaction you have just performed. _____________________________----!__________________________________ Chemical equations are more often written using the molecular formulas for the reactants and products.
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Activity 6h Write the equation for the formation of sucrose, this time using molecular formulas. Be sure to include all reactants and products formed. ____________________________ --! _________________________________ Now you need to do some accounting. The number and kinds of atoms that go into a reaction as the reactants must be accounted for in the products that were formed in the reaction. • Count the number of each kind of atom (carbon, hydrogen, oxygen) on each side of the
equation. If there are equal numbers of each, the equation is balanced. The name for this type of reaction is dehydration synthesis. Activity 6i Why is this appropriate descriptive terminology? Dehydration synthesis is also called a condensation reaction. Why is this also appropriate descriptive terminology?
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Exploration Part B. Polysaccharides You will now form a macromolecule called a polysaccharide. Procedures: 1. Join your sucrose to the sucrose of another group by dehydration synthesis until all models in
the class have been connected. 2. Be sure to form and save the water molecules that are products of the reaction in order to
balance the equation for the overall reaction. 3. Poly- means "many". Count the number of monosacharides by counting the number of rings
joined by an oxygen (red) bridge. Activity 6j How many monosaccharides are in the class molecule? _______ Activity 6k What is the total number of water molecules formed in the reactions? _______ Explanation
Activity 6l Derive the formula for the polysaccharide you produced. What is the ratio of hydrogen to oxygen? ________ Activity 6m Using molecular formulas, write a balanced equation for the formation of your polysaccharide from glucose. _______________________________________________________________________
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Activity 6n If you were a plant and all the models were glucose, what polysaccharide would you have produced? _______________________________________________________________________ SAVE THE CLASS POLYSACCHARIDE FOR LATER DIGESTION. PUT ALL WATER MOLECULES IN THE CONTAINER PROVIDED BY YOUR TEACHER. Important Information Metabolism is the sum of all chemical reactions in the body. You have studied dehydration synthesis which is an anabolic or building reaction. Plants synthesize the polysaccharide, starch, from the excess monosaccharide, glucose, formed in photosynthesis. The larger molecule is an efficient way to store the energy in glucose molecules for later use.
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Explanation
Activity 6o As consumers, we eat starch for energy. How does starch give us energy? You will now investigate the other half of metabolism, which involves catabolic or breakdown reactions. Based on your experience building a model of a polysaccharide, predict how you would convert your polysaccharide back to monosaccharides. Write a balanced equation for the reaction. ______________________________________________________________________ Exploration Activity 7 Salivary Amylase
Important Information Plants are producers, and humans are consumers. The glucose that plants produce in the process of photosynthesis is the fuel used by plant cells to stay alive. Excess glucose is stored by the plant as a polymer or long chain of glucose molecules called starch. As consumers, we eat the starch and release the glucose from the chain in order to fuel our cells.
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If we consume more starch than our cells need, what do you predict our bodies will do with the excess? ______ Important Information Starch cannot be broken down quickly or easily into molecules of glucose. Enzymes are special proteins that exist in all living systems. These proteins speed up chemical changes that would take much longer to occur if they were not present. If the proper enzyme is added to starch, it will greatly speed up this chemical reaction and change starch to glucose. An enzyme which can change starch to glucose is present in your saliva. It is called salivary amylase. In this investigation, you will use chemicals called indicators to detect the presence of starch, a polysaccharide, and glucose, a monosaccharide. You will:
(a) use iodine to test for the presence of starch. (b) use Benedict's solution to test for the presence of glucose. (c) look for evidence of enzyme action by testing a starch solution to which salivary
amylase (an enzyme) has been added.
Lab safety rule: No eating or drinking in the lab. In this lab, residual food in your mouth will adversely affect your results. Discard any candy or gum, and rinse your mouth thoroughly before beginning this experiment.
Materials: • hot plate • beaker (Pyrex) • water • iodine solution • starch solution • Benedict's solution • dropper • glass marking pencil • saliva • test tubes • test tube holder
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Procedures: Part A. Testing the Properties of Starch • Half fill a small beaker with water. Place it on a hot plate and bring the water to a boil. This
set up is a hot water bath. CAUTION: Water is very hot. Do not handle hot plate or hot glass with unprotected hands.
• Label two clean tubes a shown in Figure 7-1. • Use Figure 7-1 as a guide to filling the test tubes. CAUTION: If iodine or Benedict's solution spillage occurs, rinse with water and call your teacher immediately.
Figure 7-1
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• Heat only tube S-B in the hot water bath for 5 minutes (Figure 7-2). CAUTION: Test tube is
very hot. Handle only with test tube holder.
Figure 7-2 • After heating tube S-B, record the color of the solutions in the two tubes. The color change is
the data you will be interpreting. Use the first column of Table 7-1. NOTE: When iodine is added to the tube, you may see either a deep blue color, which indicates much starch is present, or a light blue color, which indicates the presence of some starch. No blue color indicates the absence of starch. Exploration Activity 7a Is starch present in tube S-I? ________________________________ Activity 7b Explain how you can tell.
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NOTE: When Benedict's solution is added to the tube, you should see a color. A bright blue color (original color of Benedict's) after heating tells you that glucose is not present. A change to green, yellow, orange or red after heating tells you that glucose is present. Activity7c Is glucose present in tube S-B? ____________ Activity 7d Explain in terms of the color change how you can tell.
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Exploration
Part B. Testing the Properties of Salivary Amylase Enzyme. • Label two clean test tubes as shown in Figure 7-3. • Use Figure 7-3 as a guide to filling the test tubes.
Figure 7-3
Note: Saliva will be needed for Parts B and C. In order to be a controlled experiment
a) the same donor must be used in each part, or b) a second, separate, set-up be used for each partner. What additional information would the
second set-up provide at the end of the experiment?
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Heat only tube A-B in the hot water bath for 5 minutes (Figure 7-4).
Figure 7-4 After heating tube A-B, record the color of the solutions in the two tubes. Explanation
Activity 7e In terms of the color change, how do you know if starch is present in your saliva? Activity 7f In terms of the color change, how do you know if glucose is present in your saliva?
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Exploration Part C. Testing the Properties of Starch Mixed with Salivary Amylase • Label two clean tubes as shown in Figure 7-5. (Amylase, Starch, Iodine) and (Amylase,
Starch, Benedict’s)
Figure 7-5 • Use Figure 7-5 as a guide to filling the test tubes. Note: What variable must the saliva donor
control in order to compare the results of Part C with Part A? • Mix the solutions in the tubes by swirling. • ALLOW BOTH TUBES TO STAND FOR 10 MINUTES BEFORE CONTINUING. DO
NOT ADD IODINE OR BENEDICTS UNTIL THIS TIME HAS ELAPSED. CONTINUE TO SWIRL THE TUBES EVERY MINUTE TO ENSURE THAT THE SALIVA IS IN CONTACT WITH THE STARCH.
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• During this waiting period, complete “Extending your Investigation” at the end of the lab. • After waiting, add two drops of iodine to the tube marked A-S-I (amylase, starch, iodine). • Add 30 drops of Benedict’s solution to the tube marked A-S-B. • Heat tube A-S-B only in the hot water bath for 5 minutes (Figure 7-6).
Figure 7-6 • Record the color of the solutions in the two tubes. Explanation
Activity 7g In terms of the color change, explain how you know if starch is still present in your tube filled with starch, salivary amylase and iodine?
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By comparing the depth of the color changes, evaluate if there is as much starch present now as there was in Part A. Explain why there is or is not a difference. Activity 7h In terms of the color change, explain how you know if glucose is present in your tube filled with starch, salivary amylase and Benedict’s? Summarize all your results in the table below:
Table 7-1. Testing the Properties of Amylase
Starch Only Salivary Amylase Only
Starch and Salivary Amylase Mixed
Iodine test color
Bendict’s test color
Type of carbohydrate
present (starch or glucose)
Activity 7i In Part C, was starch with salivary amylase changed into glucose? Explain you answer using your experimental results (color changes of indicators).
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Activity 7j Can starch alone change into glucose? ______ What did you add to starch to change it? _______________ Where in your body does this change take place when you eat foods containing starch? ____________________________ Why would this reaction be classified as catabolic? Activity 7k A substance upon which an enzyme causes a change is called a substrate. What was the substrate in this experiment?
____________________________ The substance which changes a substrate is called an enzyme. What was the enzyme in this experiment? ____________________________
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Exploration Extending Your Investigation Figure 7-7 represents a starch molecule. Note that it is a long molecule made up of smaller glucose molecules joined in a chain.
Figure 7-7 Salivary amylase changes starch into glucose by removing glucose molecules from the ends of the starch molecule. The best model to explain this action is that the enzyme “fits” exactly into the sites of attachment of the glucose molecules. This ‘weakens” the chemical bonds holding them together. As a result, the glucose molecule breaks from the starch molecule. Figure 7-8 represents three different enzyme molecules: A, B and C. In this model, each enzyme is represented as two separate parts.
Figure 7-8 Activity 7l What feature distinguishes one enzyme from the others? ____________ Which enzyme would best “fit” the starch molecule and break it down? ____________
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Explanation Draw the enzyme attaching to starch in the space below using the shapes in Figures 7-7 and 7-8. Activity 7m How does the starch-amylase reaction resemble a lock and key model by which enzymes may carry out their functions?
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Activity 8: Digestion of Starch You have now followed the metabolism of the macromolecule starch from its synthesis by plants using the monosaccharide glucose as a building block to its digestion by enzymes back into individual glucose molecules again. Now it is time to "digest" your 3D starch model. In this activity, the class will cooperatively digest starch with two students role-playing the enzyme, salivary amylase. • As a class, look again at the model of starch. (It should be noted that starch is actually made
of thousands of glucose units.) • Recall that in Activity 4 you needed to create bonding sites on each glucose molecule in
order to join them together in a reaction called dehydration synthesis. Activity 8a Write the balanced chemical equation for the synthesis of a disaccharide from two monosaccharides in the space provided below. Remember that reactants yield products. _______________________________________________________________________ Digestion is the reverse process in which the larger molecule is broken down into its sub-units again. Look again at the equation for dehydration synthesis. Activity 8b For the reverse process to occur, what other compound, in addition to starch, is necessary for the reaction to be balanced? (Note that enzymes are tools necessary for reactions to occur, but because they are not changed in the reaction, they are not considered reactants or products.) ______________________________________________________________________ As a class: Procedures: 1. Retrieve the starch and water models, and stretch them out on the table. 2. Identify the ring shape of each monosaccharide in the chain. Count the number of rings. This
should be the number of individual monosaccharides formed at the completion of the reaction.
3. Locate the red oxygen "bridges" connecting one ring to the next. This is where the enzyme
will break and reform bonds during the digestion process.
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4. Designate two students to be salivary amylase enzyme molecules. 5. The rest of the class will help support the starch molecule as it is being digested. 6. As the enzyme moves down the starch molecule, students should watch the reaction carefully
to see that the correct bonds are broken and reformed. 7. When the enzyme has passed, you should be holding two complete molecules of
monosaccharide. You are responsible for returning a molecule kit at the end of class with the correct number and kinds of parts.
Digestion of starch by the enzymes Beginning at opposite ends of the starch molecule, the enzyme molecules will digest the starch by adding water molecules back into the polymer. 1. Detach the oxygen bridge between the monosaccharide rings. 2. Immediately complete the freed bonding sites with a water molecule that has been
dissociated into a hydrogen atom and hydroxyl (-OH) group. Recall that this is how the water was formed during synthesis.
3. Continue the process until all reactants have been converted to products. Activity 8c Confirm that your products are correct using the scoring tool from Activity 4. Activity 8d This reaction is called hydrolysis. "Hydro-" means "water" and "-lysis" means "to split." Explain why this is an appropriate and descriptive term for this type of reaction.
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Activity 8e Classify this metabolic reaction as anabolic or catabolic and explain your reasoning. Elaboration Activity 9 You have witnessed the metabolism of carbohydrates, a class of organic compounds that is the primary energy source for most living organisms. At the spaghetti dinner, athletes will be ingesting a great deal of starch. You know that enzymes will digest the starch into thousands of glucose molecules. You also know that glucose is the preferred form of energy for all cells. But the meet is not until tomorrow. How can the body save the glucose? In this activity, you will investigate what happens to the glucose molecules after they are absorbed into the bloodstream from the intestines. Visit the websites listed in the Student Resource Manual, and research the fate of absorbed glucose. • On an anatomical diagram of the human body (provided by your teacher), draw the
carbohydrate as a simple chain entering the mouth. Draw individual links in the intestines and reconnected for storage at a site you will discover.
Activity 9a What is the name of the animal carbohydrate storage molecule?
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Activity 9b How does glycogen differ from starch? Activity 9c Where is it stored? Activity 9d How will eating a spaghetti dinner affect glycogen deposits?
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Evaluation It is time to prepare your talk for the team. Remember your job is to provide hard scientific evidence that will inspire the team to attend the spaghetti dinner and eat heartily. Write at least three persuasive paragraphs explaining how carbohydrate loading supplies energy in muscle tissues and will therefore enhance the team's performance tomorrow. Use visuals such as diagrams and props to increase the runners understanding.
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Student Resource Booklet
Name:
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Web Sites for Students:
1. http://people.ne.mediaone.net/jkimball/BiologyPages/C/Carbohydrates.html 2. http://wwwnhmccd.edu/public/nsci/bio/dehydrat/dehydrat.html 3. http://www.eufic.org/foodtoday/eng/ft11/foodwatch.html 4. http://www.mayohealth.org/mayo/9903/htm/carbohyd.htm 5. http://kauai.cudenver.edu:3010/0/nutrition.dir/salva.html 6. http://kauai.cudenver.edu:3010/0/nutrition.dir/carbos.html 7. http://www.cafecreosote.com/Reference/PastaPage.html 8. http://kauai.cudenver.edu:3010/0/nutrition.dir/carbint.html 9. http://ww.fac.swt.edu/BIO_1410/BioChemSite/Docs/Dehydration.html 10. http://www.bodywise.org/carbo.html 11. http://www.sportnutrition.com/scarru.html 12. http://www.propelsports.com/home.html 13. http://www.chemfinder.com/cgi-win/cfserver.exe/ 14. http://naturalsciences.sdsu.edu/classes/lab2/carbohydrates.htm
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Assessment and Evaluation Tools
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Activity 1: Go For the Gusto
Name: _______________________________ Partner_____________________________ Date: ________________________________ Assessment Self Teacher 1.
Appropriate tools, techniques and units (SI) were selected for making measurements.
2.
I worked cooperatively with others in my group.
3.
The set of data is recorded in an organized way (list, table or chart) so that patterns in the data can easily be discerned.
4.
Careful measurements were taken in order to minimize systematic error.
5.
The set of data shows that the same experiment was repeated.
6.
Sufficient data analysis was conducted to allow for the drawing of conclusions.
Assessment/Evaluation Tool
4 Expert 6 out of 6 are checked.
3 Proficient 5 out of 6 are checked.
2 Emergent 4 out of 6 are checked.
1 Novice 3 or fewer are checked.
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Activity 2: "Molecules Have Bodies, Too"
Name: _______________________________Partner:_____________________________ Date: ________________________________
Assessment Self Teacher 1.
I understand the similar chemical makeup of carbohydrates as evidenced by my work.
2.
I understand the meaning of subscripts in a molecular formula.
3.
I am able to derive the formula for a monosaccharide.
4.
I am able to use my knowledge of molecular and structural formulas to explain isomers.
5.
I am able to explain how it is possible for monosaccharides with the same molecular formula to taste differently
Assessment/Evaluation Tool
4 Expert 5 out of 5 are checked.
3 Proficient 4 out of 5 are checked.
2 Emergent 3 out of 5 are checked.
1 Novice 2 or fewer are checked.
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Activity 3: Consumer Product Analysis
Name: _______________________________Partner:_____________________________ Date: ________________________________ Assessment Self Teacher 1.
The data collection table is appropriately sized and clearly displays all the collected data.
2.
The data collection table has a title that reflects what the table displays.
3.
All the headings/rows/columns of data are correctly labeled.
4.
The set of data was recorded under the appropriate heading/row/or column.
5.
All measurements are labeled with the correct magnitude (numerical value) and unit.
6.
My news release is written with correct language usage and spelling.
7.
My new release contains purposeful and accurate information to adequately explain the topic.
Assessment/Evaluation Tool
4 Expert 7 out of 7 are checked.
3 Proficient 6 out of 7 are checked.
2 Emergent 5 out of 7 are checked.
1 Novice 4 or fewer are checked.
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Activity 4: Making and Using Models
Name: ______________________________Partner:______________________________ Date: _______________________________ Topic: Linear Model of Glucose Assessment Self Teacher 1.
Used correct number and kinds of atoms.
2.
Each atom has all bonds formed.
3.
Arrangement of atoms corresponds to structural formula provided.
4.
Can demonstrate the formation of one isomer.
5.
Can identify functional groups.
6.
Can demonstrate dehydration synthesis using correct terminology.
7.
Can write a balanced equation for the reaction.
8.
Can predict the products resulting from the polymerization of five units and write a balanced equation for the reaction.
Assessment/Evaluation Tool
4 Expert 8 out of 8 are checked.
3 Proficient. 7 out of 8 are checked
2 Emergent 6 out of 8 are checked.
1 Novice 5 or fewer are checked.
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Activity 5: Chains to Rings
Name: _______________________________Partner:_____________________________ Date: ________________________________ Assessment Self Teacher 1.
I correctly followed all directions.
2.
I am able to use my model to interpret molecular formulas.
3.
Using my model, I am able to answer both structural and molecular questions.
4.
I am able to relate properties of substances to their molecular structure.
5.
Using my model, I am able to see the structural difference between the isomers glucose and fructose.
Assessment/Evaluation Tool
4 Expert 5 out of 5 are checked.
3 Proficient 4 out of 5 are checked.
2 Emergent 3 out of 5 are checked.
1 Novice 2 or fewer are checked.
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Activity 6: Monomers to Polymers
Name: _______________________________Partner:_____________________________ Date: ________________________________ Assessment Self Teacher 1.
I am able to use my model to make predictions.
2.
I am able to use my model to understand chemical reactions better.
3.
I am able to use my model to write molecular formulas.
4.
I am able to differentiate between reactants and products.
5.
I am able to demonstrate my understanding of chemical equations.
6.
Using molecular formulas, I am able to write balanced equations
7.
I am able to infer how starch gives us energy.
8.
I worked cooperatively with my partner.
Assessment/Evaluation Tool
4 Expert 8 out of 8 are checked.
3 Proficient 7 out of 8 are checked.
2 Emergent 6 out of 8 are checked.
1 Novice 5 or fewer are checked.
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Activity 7: Salivary Amylase
Name: _______________________________Partner:_____________________________ Date: ________________________________ Assessment Self Teacher 1.
Using my knowledge of molecular structure, I am able to make predictions.
2.
I followed all safety procedures for the Science Lab.
3.
I read the procedure carefully and conducted the experiment without error.
4.
I made careful observations and recorded my data accurately.
5.
My experiment had a control.
6.
I am able to interpret my data and draw conclusions.
7.
I can demonstrate my knowledge of enzymes by making a "lock and key" drawing.
8.
I worked cooperatively with my partner.
Assessment/Evaluation Tool
4 Expert 8 out of 8 are checked.
3 Proficient 7 out of 8 are checked.
2 Emergent 6 out of 8 are checked.
1 Novice 5 or fewer are checked.
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Activity 8: Digestion of Starch
Name: _______________________________Partner:_____________________________ Date: ________________________________ Assessment Self Teacher 1.
I can take meaningful and relevant notes.
2.
I can identify and use proper references.
3.
I used precise language and specific detail.
Assessment/Evaluation Tool
4 Expert 3 out of 3 are checked.
3 Proficient 2 out of 3 are checked.
2 Emergent 1 out of 3 is checked.
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Activity 9: Carbohydrate Loading
Name: _______________________________Partner:_____________________________ Date: ________________________________ Assessment Self Teacher 1.
I used precise and specific detail correctly.
2.
I can write fully developed paragraphs with information specific to the subject and relevant to the focus.
3.
I sustained a logical order throughout the piece.
4.
I edited writing using the conventions of the language (spelling, punctuation, sentence structure).
Assessment/Evaluation Tool
4 Expert 4 out of 4 are checked.
3 Proficient 3 out of 4 are checked.
2 Emergent 2 out of 4 are checked.
1 Novice 1 or fewer are checked.
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Writing to Persuade (Holistic Rubric) Expert [ ] Development: The writer identifies a clear position and fully supports or refutes that position with relevant
personal and/or factual information. [ ] Organization: The writer presents an organizational plan that is logical and consistently maintained. [ ] Attention to Audience: The writer effectively addresses the needs and characteristics of the identified
audience. [ ] Language: The writer consistently uses language choices to enhance the text. Proficient [ ] Development: The writer identifies a clear position and partially supports or refutes that position with
relevant personal and/or factual information. [ ] Organization: The writer presents an organizational plan that is logical and maintained, but with minor
flaws. [ ] Attention to Audience: The writer adequately addresses the needs and characteristics of the identified
audience. [ ] Language: The writer frequently uses language choices to enhance the text. Emergent [ ] Development: The writer identifies a position, yet that position lacks clarity. The writer tries to support or
refute that position with relevant personal and/or factual information. [ ] Organization: The writer presents an organizational plan that is only generally maintained. [ ] Attention to Audience: The writer minimally addresses the needs and characteristics of the identified
audience. [ ] Language: The writer sometimes uses language choices to enhance the text. Novice [ ] Development: The writer identifies an ambiguous position with little or no relevant personal and/or factual
information to support that position, or the writer fails to identify a position. [ ] Organization: The writer presents an argument that is illogical and/or minimally maintained. [ ] Attention to Audience: The writer does not address the needs and characteristics of the identified audience. [ ] Language: The writer seldom, if ever, uses language choices to enhance the text.