Lesson 1: Anchoring Phenomenon - Battle of Kruger After watching “The Battle of Kruger” phenomenon, do the following: Individually, write 3 scientific questions here. Do not stop to judge or answer any questions. Your questions: When directed, with your group write down every question by your group members exactly as it was stated. Copy your three questions to the table below as well. Discuss the questions as your group provides them. Then, prioritize which questions are most important. Number your questions, with #1 being the most important. Question Prioritize Lesson 2: Battle of Kruger Observations Making Sense of a Phenomenon Using the video, determine how the species’ physical and behavioral traits are adaptive, or increase their chances of survival. Species: Crocodile How Adaptive? Observations: Species: Buffalo How Adaptive? Observations: Species: Lions How Adaptive? Observations: How are these 3 species similar and different in physical and behavioral traits? Define the following terms: OBSERVATION: __________________________________________________________________________ INFERENCE: ____________________________________________________________________________ Lesson 3: Life as a Hunter Driving Question: Why do you think lions live in a group? Why do you think the buffalo live in a group? What do you notice? What do you wonder? Discuss your notice and wonder with your group members. Can you answer the following: What do you think was motivating the lions to behave the way they did in the video? Why do organisms like lions consume things? Based on the data you see in the table, what do you think would be the optimal prey for lions? What prey could give the lions the greatest net gain of energy? Life as a Hunter Round 1: Life is challenging for a female lion in Etosha National Park. If a female’s body size is approximately 130kg, she must consume at least 13,500 kcal/day to survive and succeed in the environment. There are ample prey species available, but just living and breathing costs a significant amount of energy per day. This means, that regardless of her hunting success, she will utilize energy for her resting metabolic rate. All animals have a reserve of energy stored as large molecules in their cells that they can use for activities throughout the day. Female lions have approximately 15,000 kcal to expend during hunts and, therefore, cannot expend more than 15,000 kcal for each hunt. Your “kcal cash” will represent this usable amount of energy. Materials: 10 - 1,000 kcal cash 10 - 500 kcal cash Listed below are four prey species lions will hunt and the energy costs and gains for hunting each type of prey. Mass of prey item Total energy cost to hunt & kill (kcal) Total energy available per kill (kcal) Meerkat 0.77 kg -3,000 +1,000 Warthog 60 kg -5,000 +12,000 Wildebeest 265 kg -10,000 +25,000 Zebra 310 kg -55,000 +170,000 Round 1: You are tracking a female lion. Determine how many of each prey species she would need to successfully hunt and eat to gain the amount of energy she needs per day (13,500 kcal). Remember, an individual lion cannot expend more than 15,000 kcal per hunt. Use the following calculations to determine the net energy gained in kilocalories for the table below. Lions rest ~90% of each day, allowing for only 1-3 hunting events per day, depending on the size of the prey. It can take a pride more than a day to fully consume a large prey so one successful hunt per day or every few days is the norm. Minimum number of prey hunted and consumed Energy cost per prey (kcal) (-) Total energy cost to hunt prey (must expend less than 15,000 kcal/day) Energy available from this prey (kcal) (+) Net energy gained (kcal) Is this species worthwhile to hunt on your own? Meerkat Warthog Wildebeest Zebra 1. Based on the data in the model provided, is hunting small prey more often or large prey less frequently more efficient? Explain your reasoning. 2. What strategies must be used to capture larger prey? Claim-Evidence-Reasoning Write a simple statement as to whether hunting solo or in groups is most effective for lions to gain the energy they need to survive. Claim: ________________________________________________________________________________________ ______________________________________________________________________________________________ Evidence: ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ Reasoning: ______________________________________________________________________________________________ ______________________________________________________________________________________________ ______________________________________________________________________________________________ ______________________________________________________________________________________________ ______________________________________________________________________________________________ ______________________________________________________________________________________________ ______________________________________________________________________________________________ ______________________________________________________________________________________________ ______________________________________________________________________________________________ ______________________________________________________________________________________________ ______________________________________________________________________________________________ ______________________________________________________________________________________________ ______________________________________________________________________________________________ ______________________________________________________________________________________________ Round 2: How do organisms like lions maximize their energy input and minimize their energy output? Lions live in prides consisting of males, females and juvenile cubs. Depending on their sex, size, and age, lions have different kcal requirements per day. Males require 17,500 kcal/day Females require 13,500 kcal/day Juveniles require 11,500 kcal/day The pride you are following consists of 1 male, 4 females, and 3 juveniles. Recall from the video, that females typically are the pride members that do the hunting. Calculate how much energy your pride will need to sustain itself per day. Show all work here: What prey items should your pride attempt to catch to have enough energy for the day? - As a group, figure out the optimal prey to feed your pride. - Did your optimal prey from Round 1 change or stay the same? - Explain by showing your math. Final impressions: Be prepared to share your responses below during a class discussion. 5. Beyond obtaining energy, what other benefits occur from living in a group? Lesson 4: Lulu the Lioness Driving question: Why do lions live in groups? Define the following terms: Allele Gene Chromosome Genotype Phenotype Homozygous Heterozygous Karyotype Data Set 1: Behavioral Observation Data - Based on the Field Notes, answer the following questions with your group: Summarize what seems to have happened in the pride during the period of observation. Who are the probable parents of the cubs? What ideas do you have about who fathered the cubs? What evidence do you have? What ideas do you have about who mothered the cubs? What evidence do you have? Data Set 2:Geographical Observation Data - Based on the Data, answer the following questions with your group: Identify the 3 most significant observations from the data provided: Did this new data change your hypothesis about the parents? What evidence caused you to change or support your previous hypothesis? What data would be helpful in testing your hypothesis at this point? Research: African Lion Using the internet, research the African Lion species to help us better understand their relationships. Answer the following questions: Briefly describe the roles that males and females play in the pride. What role do lions fill in their habitat? Why is this role critical to maintain a healthy community? Which sex is mainly responsible for this role? Who is responsible for controlling the pride’s territory? If the pride is taken over by new individuals, what happens to the… Females? Males? Cubs? How are cubs raised within the pride? How do the roles filled by the females increase the survival of the species? How do the roles filled by the males increase the survival of the species? Explain how exhibiting group behavior like these lions increases the survival of individuals within the species. Does this research support your hypothesis of who are the mother and father of the cubs? (YES, NO, OR NOT ENOUGH INFO) Explain how this information either supports your hypothesis or made you rethink it. Data Set 3: Karyotype Data With your group: Carefully observe the karyotypes, determine whether patterns exist and discuss Discuss if the karyotypes help determine who the probable parents of the cubs Determine whether your hypothesis for parentage changed based on this new data Answer the following: Why are the chromosomes paired? What does this tell you? From where do lion cubs get their chromosomes? How does this happen to produce the pattern you see in the karyotype? How can your answer from #2 help us prove who the parents are? Does this karyotype help you determine the parentage of the cubs? _______ What other information would be helpful to answer your question? Data Set 4: Female Lion & Cub Genotype Data Using this data: Look for patterns in the data. Consider possible family relationships that exist among the members of the pride based on this data. Discuss with your group how this data could be used to definitely determine who the mother is of the cubs. Determine whether your hypothesis for parentage was proven true or false, citing evidence. Then, answer the following: How can you make sense of this genotype data and how can it be used to determine parentage? What other information do you need to determine parentage? Data Set 5: Complete Pride Genotype Data Now that you have the genotypes of all the lions in the pride, determine the parents of the cubs. Make your notes in the space below and use the data table on page 14 of your notes. Then, answer the following: How can you make sense of this genotype data and how can it be used to determine parentage? How was this different now that the male genotypes are available? Did this data prove your hypothesis? Cite your evidence. Lesson 5: Mapping Lion Populations Driving Question: How do we know which lions are related to each other? Make some observations of where the different lion populations are found across the continent of Africa. Notice which populations are closer to one another and which are further from others. OBSERVATIONS: Which populations would you predict are more closely related to one another? Explain why you answered the previous question the way you did. Analyzing Microsatellite Data You were initially given a “bar” that represented a set of alleles carried by a lion within a population. We now know that lion populations share many family members and, therefore, more similar alleles. But how do the alleles of different populations compare to one another? Using the full set of allele bars from all of the populations listed on the previous page, use the following questions to help guide your thinking. Write 2 populations that have very similar alleles. ________________________________________________ Why did you choose these 2 populations? How do the two populations you chose above compare to one another geographically? Based on geography, give one population you would expect to be very genetically different from many of the other populations. Why did you choose this population? With which other population does the Fannie Roberts population seem to share many of its alleles? Why is that finding unusual based on your understanding of the lion geography? In Zambia, which 4 lions are likely to have migrated from a different population? _______________________ From which population do you believe they may have originated? __________________________________ How does the geography of these two populations support or refute that finding? Using evidence from your map, explain why the alleles in the Cameroon population are different from all the other lion populations. The Etosha population is located in a National Park. Explain why the lions in this population may be genetically similar. (Consider how a population in a park is different than a wild population) In your own words, explain how geography influences genetics. Define the following terms: Gene Flow Genetic Variation Gene Pool Phylogenetic Tree Lesson 6: Lion Phylogeny Driving Question: How do we know which lions are related to each other? Look at the DNA samples from Cytochrome b shown above. What do you notice about the sequences for each population? Lion populations are found all over Sub-Saharan Africa. How do the sequences above reinforce or contradict the idea that populations of lions who are genetically similar live in the same geographic area? Based only on the DNA, which populations do you think live in closer proximity to each other? What do you expect to see when comparing genes of lions that live closer together? With the previous activity, multiple genes were used to create the bar microsatellite data. Now that we are zooming in on one gene, does the data support yesterday’s conclusions? Cite specific evidence to support your answers. We will now use the DNA sequences to analyze the DNA in order to find which lion population are most closely related. You will observe a Phylogenetic tree on the next page while thinking about what you have figured out from the DNA sequences above. BOT2 and Etosha45 populations are on the same branch of the phylogenetic tree. What explanation can you propose from this observation? In the activity you did in the last class, you made a prediction about which prides lived closer together. In what way does this phylogenetic tree support or refute your prediction? On the phylogenetic tree, tigers are farther from the other populations on the tree. How does this observation support what you already know about lions and tigers? Think back to where the lion populations are on the geographic map of Africa. Compare the proximity of populations on the phylogenetic tree to location on the geographic map. Cite specific examples where the geographic location and genetic evidence shows relatedness. What assumptions can you make about these observations? Lesson 8: How is Energy Used in Organisms? Driving Question: How do different organisms obtain their energy? Refer to the Model A above to fill out the table below. Organism A Organism B Amount ingested (kg) Amount needed to maintain biomass (kg) Amount egested (kg) What’s “missing”? What do you think “egested” means? _________________________________________________________ Show your calculations to support your answer for “What’s missing?” Organism A Organism B What else do the organisms do with the food they ingest besides maintaining biomass and waste production? Is Organism A a carnivore or an herbivore? ________________________________ Is Organism B a carnivore or an herbivore? ________________________________ In Model B, what are three of the ways energy is used by the organisms? a. _______________________ b. _________________________ c._____________________________ Use Model B to fill out the table below. Elephant Lion Food Ingested (Kcal) Egested waste (Kcal) Respiration (Kcal) Heat Loss (Kcal) Does the amount of energy from the food eaten (Kcal) by each organism equal the amount of energy used by each organism? Support your answer by showing your calculations. EXTENSION: Calculate the amount of potential energy that each organism does not use efficiently. Support your answer by showing your calculations. (Egested waste and heat loss are not an efficient use of energy) Formula: heat loss + egested waste x 100 = percentage food ingested The elephant and the lion do not have the same amount of efficiency when using energy. Which organism is more efficient - the elephant or the lion? (circle one) Give a reason which could account for this difference. ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ Using the information in Model B as a reference. Which of the following from the elephant is directly available to the lion? Grass Respiration Biomass (circle one) What percentage of the elephant’s “grass energy” is available for the lion? Support your answer by showing your calculations. In the formula below, “Total kcal used” is calculated by adding together respiration + egested waste + heat loss. Formula: Total kcal ingested – Total kcal used X 100 = % Total kcal ingested Lesson 9: Animal Nutrition Lab Driving Question: How do animals obtain their energy? Data Set 1: Digestive Tracts Herbivores, Omnivores, Carnivores….Oh My! Background Tina Vega, zookeeper at Brookfield Zoo, is constantly addressing the nutritional needs of different species in her care. The nutritional needs within a wild community or a zoo’s animal collection can be highly diverse. Different species are not only adapted for catching and eating their food with specialized teeth, claws, beaks or talons, but also possess highly specialized digestive organs that help them break down their individual diets. Some animals have very long digestive tracts to break up the tough cellulose of plant material where carnivores have relatively short intestinal tracts. In this laboratory activity, you will assess the needs of select species from an African community as zookeepers like Tina do in order to determine whether they are an herbivore, omnivore or carnivore. How would you define the following? Carnivore: ____________________________________________________________________________________ ______________________________________________________________________________________________ ______________________________________________________________________________________________ Omnivore: ____________________________________________________________________________________ ______________________________________________________________________________________________ ______________________________________________________________________________________________ Herbivore: ___________________________________________________________________________________ ______________________________________________________________________________________________ ______________________________________________________________________________________________ Detrivore: ____________________________________________________________________________________ ______________________________________________________________________________________________ ______________________________________________________________________________________________ Predictions Using the diagrams of the digestive systems on the next page, hypothesize to what feeding niche each species belongs. (C = carnivore, O = omnivore, H = herbivore) belongs. (C = carnivore, O = omnivore, H = herbivore) Species Feeding niche (Circle One) Evidence African Lion C O H African Elephant C O H Zebra C O H Black Rhino C O H Guinea baboon C O H Hedgehog C O H Aardwolf C O H Human C O H Big question: What other organ(s) besides what is pictured play an important role in mechanical digestion? ______________________________________________________________________________________________ Data Set 2: Dentition Data Set 2: Dentition Data Set 3: Dietary Requirements Table 1 Using the nutritional requirements provided, determine the minimum daily amounts of each nutrient for each species. Each of the values represents the daily minimum requirement as mass (kg). Some diets vary due to different levels of fiber (indigestible plant material) consumed. There is 0.454 kg in 1.0 lbs. Do the conversions and fill in the table below. Species Protein (minimum kg needed) Fats (minimum kg needed) Carbohydrates (minimum kg needed) Daily Amount Required kg lbs African Lion ≥ 3.5kg ≥ 0.50 0.00 5.50-6.80 12.13-14.99 African Elephant ≥ 4.41 ≥ 1.10 ≥ 41.36 55.15-59.25 121.58-130.62 Zebra ≥ 0.90 ≥ 0.13 ≥ 5.40 10-15 22-33 Black Rhino ≥ 1.64 ≥ 0.41 ≥ 15.38 20.50-22.5 45.19-49.60 Guinea baboon ≥ 0.11 ≥ 0.02 ≥ 0.16 0.40-0.65 0.88-1.433 Hedgehog ≥0.01 ≥ 0.005 ≥0.001 0.015-0.020 0.033-0.044 Aardwolf ≥ 0.055 ≥ 0.125 ≥ 0.00 0.25-0.30 0.55-0.66 Human ≥ 0.22 ≥ 0.08 ≥ 0.40 1.00 - 1.40 2.2-3.08 What about Detrivores? Here is the digestive system of a vulture. Vultures are detritivores, meaning they consume dead organisms. Observations & Inferences As you continue to compare this system to others, name some differences that birds seem to have that mammals do not: _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ Dietary Planning: This is critically important information for you to design your diets! Different species can have very specific needs. When feeding animals, whether it is at the zoo or your own pet at home, it is vital for you to provide a diet that is biologically appropriate. Using the tables on the next page, work with your group to create a biologically appropriate diet for the species listed. Using the food options provided, include dietary items in each table that meet or exceed each species’ minimum needs. For information about the needs of each species, See the Species Information Cards. Each species should have a minimum of 3 food items daily. To get the mass of total proportion to be fed each day, multiply the portion size by the percentage of each macromolecule category (protein, fat, carbohydrate). If you are struggling to keep within the recommended range for your species, consider reducing the portion size, which will not have an impact on its macromolecule percentages. Species Name: _________________________________ Dietary item Proteins Fats Carbohydrates Portion size (kg) % Mass of protein content Portion size (kg) % Mass of protein content Portion size (kg) % Mass of protein content Total Daily Mass Analysis Questions In what types of foods is the protein content the highest? In what types of foods is the carbohydrate content the highest? Fill out the table: Species Trophic Level (Circle One: Primary, Secondary, Tertiary) Evidence Lion P S T Elephant P S T Zebra P S T Black Rhino P S T Guinea Baboon P S T Hedgehog P S T Aardwolf P S T Human P S T Does the type of animal (ie. mammal, reptile, amphibian, bird) necessarily determine at which trophic level that organism exists? Why are detritivores a critical part to any community? Which of the animals you studied live in social groups? How could this affect their nutritional needs? Do individual animals have the same dietary needs every single day of the year? Why or why not? Does the diet you designed exactly meet the requirements stated above? Do you think the requirements as stated are exactly what each animal needs everyday? Explain why or why not. Lesson 9.5: Introduction to Photosynthesis, Cellular Respiration and Macromolecules Driving Question: How does sunlight become energy that keeps lions and elephants alive? Notes: ATP Relay Round 1: Where did the energy inside the glucose come from? _______________________________________ Round 2: Does the Elephant receive usable energy? ________________________________________________ Round 3: Why is ATP more useful than glucose? ___________________________________________________ Round 4: What happens if the Elephant runs out of ATP? _____________________________________________ Round 5: Why can't the Lion steal ATP from the Elephant? ____________________________________________ Challenge Questions: Which organism captured energy from sunlight? Which process made glucose? Which process made ATP? Who performed cellular respiration? □ Grass □ Elephant □ Lion Did ATP travel from Grass to Elephant? Explain. Did ATP travel from Elephant to Lion? Explain. 7 Complete the energy pathway. Sun ↓ _______________ ↓ _______________ ↓ _______________ ↓ ATP _______________ Final Challenge Imagine all of the grass disappeared from the African savanna. Discuss with your group: What would happen to the Elephant? What would happen to the Lion? What would happen to ATP production in both animals? Be ready to explain your thinking using the words: Photosynthesis Glucose Cellular Respiration ATP Card Sort Challenge Wrap Up Questions: Which organisms perform photosynthesis? Which organisms perform Cellular Respiration? What molecule stores usable energy? Where does ATP come from? Where does Glucose come from? Where does plant glucose come from? Lesson 10: Macromolecules: What are the Building Blocks of Life? Driving Question: How does the food an elephant and a lion eat become the energy their cells use to stay alive? Background Information: From the smallest single-celled organism to the tallest tree, all life depends on the properties and reactions of four classes of organic (carbon-based) compounds—carbohydrates, lipids, proteins, and nucleic acids. We will spend an entire unit later in the year on nucleic acids. Carbohydrates, Lipids, and Proteins are the 3 building blocks of all living things that we will focus on in this unit. These are called macromolecules because they are large molecules. They are responsible for most of the structure and functions of the body, including energy storage, insulation, growth, repair, and communication. Simple organic molecules can be joined together to form all the essential biological molecules needed for life. Directions: Analyze Model 1 and answer the questions that follow. Questions: A carbohydrate is a macromolecule. This means that it is a large or small molecule. (circle one) Use Model 1 to show which atoms are present in each type of molecule by listing the symbol for each atom included (an atom = element in the molecule). Carbohydrate has been done for you. Carbohydrate: C, H, O Lipid: _________________ Protein: ___________________ List 3 similarities between the 3 types of macromolecules. __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ List 3 differences between the 3 types of macromolecules. __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ READ THIS! During chemical reactions, the bonds in molecules are continually broken and reformed. When bonds are broken, there is a net energy release that creates energy molecules called ATP. ATP molecules are energy molecules that allow cells to do the work needed to keep the organism alive and functioning. Since more energy is released than absorbed during a chemical change like this, the process can be used as a source of energy. A general rule for processes such as cell respiration is the more carbon atoms there are in a molecule, the more energy that molecule can provide to the organism when it is used as food. Using the information from above and Model 1, is a carbohydrate, lipid, or a protein more likely to be a good source of energy for an organism? Use comparative data to support your answer. Background Information: There are many chemical reactions occurring in your body right now. As you eat food, these food molecules are broken down by enzymes and a chemical reaction takes place. The bonds between elements are broken and reformed – energy can be given off or taken in when the reaction occurs. The left side (before arrow) of the reaction (what goes in) is called the reactants while the right side (after arrow) of the reaction (what comes out) is called the products. The number of elements that go into the reaction should be the same number of elements that come out of the reaction. Analyze the two models showing the elephant’s diet and lion’s diet and answer the questions that follow. The reactants are _____________________________ and _____________________________. The products are _____________________________ and _____________________________. Would you say that glucose or sucrose is more complex? Circle one. Why?? In your own words, describe the process that is occurring here and how it applies to your own body. What is the purpose of this reaction in any organism? Starch is a complex carbohydrate found in plants which contains approximately 200 glucose molecules. What do you think the benefit could be for plants to produce starch? How is the chemical reaction here similar to the one in Model 2? In your own words, describe the process that is occurring here and how it applies to your own body. Read This! There are only 20 different amino acids found in the body, however, there are thousands of different proteins being used by your cells. Proteins differ in their types and sequence of the number of amino acids which allows for the thousands of different proteins found in your body. When you consume protein, it is broken down into individual amino acids. These amino acids are then used to make new proteins. Amino Acid 1 Amino Acid 2 Amino Acid 3 Based on the information above about how proteins are made and are different, bond the 3 amino acids above together to create a protein. Remember that each carbon can only form 4 bonds. Circle the OH from one amino acid with the H of the next amino acid (to become H2O) that must drop off to bond the carbon at the end of one amino acid to the nitrogen of the next. Use a pencil! The reactants are _____________________________ and _____________________________. The products are _____________________________ and _____________________________. What can we predict about the potential energy available in a monoglyceride molecule which has more carbon atoms than a glucose model? Lesson 11: Enzymes Driving Question: How do animals get energy from their food? Make some observations of the above model. In a sentence or two, describe what you are seeing occurring in this model. Based on what you have been figuring out in class recently,what could this model represent? Explain using evidence. Amoeba Sisters: Enzymes Video Worksheet Part A: Fill in the Blank Use the words in the word bank to complete each statement. Each word is used once. Word Bank: active site • catalysts • enzymes • products • proteins • substrate Most enzymes are a type of biomolecule called __________________________. Enzymes act as biological __________________________ by speeding up chemical reactions. The molecule on which an enzyme acts is called the __________________________. The specially shaped region where a substrate binds to an enzyme is the __________________________. After an enzyme changes a substrate, the resulting molecules are called __________________________. __________________________ can help build molecules or break molecules apart. Part B: Multiple Choice Circle the best answer. How does an enzyme affect the amount of energy needed to begin a chemical reaction? A. It increases the energy needed. B. It decreases the energy needed. C. It completely removes energy from the reaction. D. It changes energy into matter. Why can an enzyme usually interact with only certain substrates? A. Enzymes are found only in certain cells. B. Every substrate has the same shape. C. The enzyme’s active site has a specific shape. D. Enzymes can be used only once. During induced fit, what happens when a substrate binds to an enzyme? A. The enzyme slightly changes shape to fit the substrate. B. The enzyme is permanently destroyed. C. The substrate changes into an enzyme. D. The active site disappears. Lactase is an enzyme that helps break down: A. proteins B. fats C. lactose D. oxygen Which condition could cause an enzyme to become denatured? A. Exposure to an extremely high temperature B. Being used in a chemical reaction C. Binding to the correct substrate D. Producing a product A helper that assists an enzyme and is made from an inorganic substance, such as a mineral, is called a: A. substrate B. cofactor C. product D. carbohydrat Part C: Short Answer Answer in one or two complete sentences. Explain why enzymes are important to living organisms. Enzymes are not used up during a chemical reaction. Why is this helpful to a cell? A stomach enzyme works best in acidic conditions. Predict what might happen if the enzyme were placed in an environment with a very different pH. A person does not produce enough lactase. Explain why this person may experience discomfort after consuming dairy products. How are the macromolecules broken up and built up again? One of the functions of enzymes is what you described after looking at the model provided on page 43. Different enzymes have different functions but let us start with the context of digestion for now. You are going to use models to illustrate how some enzymes work. Each student will play a role as an enzyme that acts in a specific place in the digestive system. Two students will be enzymes in the lion and two will be enzymes in the elephant. Carbohydrates will be symbolized by strings of hexagons and proteins will be symbolized by strings of circles. The hexagons represent individual glucose molecules, and the circles represent individual amino acids. In this activity, we will not model digestion of fats. Directions: One student from each group will combine the macromolecule with the enzyme assigned to them and model the digestion that takes place. That student will then pass the pieces to their partner who will model how their enzyme acts on the remaining pieces. Be prepared to model and explain to your teacher how enzymes work on different macromolecules. Questions: Which two enzymes function in carbohydrate digestion? How do you know? Which of these two enzymes would come first? How do you know? Which two enzymes function in protein digestion? How do you know? Which of these two enzymes would come first? How do you know? Lion and Elephant Digestive Systems You have learned that elephants and lions have different diets: elephants primarily eat carbohydrates and proteins, and lions primarily eat proteins and fats. Because their food is made up of different macromolecules, they require different enzymes to break down food into smaller and smaller substances that can then be absorbed into the blood and taken to the parts of the body where they are needed for energy and growth. In addition, enzymes are found in specific parts of the digestive system. For instance, protein digestion begins in the stomach and the process continues in the small intestine. Fats are digested in the small intestine. Carbohydrate digestion begins in the mouth and continues in the small intestine. Label the models below where protein, fat, and carbohydrate digestion occur. Lactase Enzyme Model: Explain what the lactase enzyme does based on the model below. Lactose is the sugar found in milk. Lion cubs and elephant calves stop producing the lactase enzyme when they wean from their mother’s milk. After this occurs, they stop producing lactase enzymes. Explain what and how lion cubs and elephant calves (and even human babies) are digesting before they can find and eat food on their own like adult animals. What would happen in the digestive system of a mammal after the lactase enzyme stops being produced if the mammal drinks milk? Humans are unique among animals as some humans can continue drinking milk and eating dairy products as adults long after they have been weaned from their mother’s milk. What must be occurring based on what you have figured out so far? Some people are lactose intolerant and can’t drink milk past weaning. What must be different based on your answer to the previous question? Read for understanding: Enzymes are proteins that lower the amount of energy it takes for a chemical reaction to occur. They have a specific shape and function and match with another molecule, which is called the “substrate.” The enzyme and the substrate fit together like a lock and key, much like the initial model you viewed at the beginning of this lesson. Enzymes have a space on their structure called the “active site” that is shaped to fit with its substrate, making the enzyme specific for its substrate. A specific chemical reaction takes place in the active site. Note that the enzyme is not part of a chemical reaction, and its active site can be used again and again. Every chemical reaction in an organism requires its own enzyme, but in this activity, we will model a few of the enzymes that are used in digestion of macromolecules. Even though these enzymes are responsible for breaking down our food into smaller pieces so they can make it into our blood and cells, other enzymes were used to create these molecules in the first place! Explain how enzymes are important not only for breaking down proteins, but also for the process of building new proteins for cells and the body. Enzyme Questions 1. Using this graph, a. What is the optimal temperature for this enzyme? _________________ b. Why do you think the graph drops off so suddenly? ________________ 2. A student puts 10 ml of enzyme into a test tube with 50 ml of substrate and notices that it takes 2 minutes for the reaction to be completed. The student then puts 20 ml of enzyme into another test tube with the same amount of substrate. How long do you think the reaction will take? 1 minute 2 minutes 3 minutes WHY? 3. The student then puts 10 ml of enzyme into a test tube with 100 ml of substrate. How long do you think the reaction will take? 2 minutes 3 minutes 4 minutes WHY? 4. Look at the reaction to the right. a. What is the enzyme? b. What is the substrate? c. What are the products? 5. Lipase is a digestive enzyme that digests fat droplets in the small intestine. Indicate which of the following test tubes would show digestion and explain why if they do not. a. Tube 1: water and fat droplets: b. Tube 2: water, fat droplets and lipase: c. Tube 3: water and lipase: 6. The sweet taste of freshly picked corn is due to the high level of sugar in the kernels. When the corn is stored for a few days before eating it is not as sweet because the plant has enzymes which convert about 50% of the sugars to starch. To preserve the sweetness of the freshly picked corn you can immerse the ears in boiling water for just a few minutes as soon as possible after picking. If the corn is processed this way and then frozen it will retain its sweetness. What is the reason this method works? 7. Meat tenderizers contain enzymes that interact with meat and help break down the meat proteins so that the meat will be more tender and juicy after cooking. The directions for the meat tenderizer say to sprinkle it all over the surface of the meat and have it sit at room temp for 30 minutes. If meat is coated with tenderizer and then placed in the refrigerator how would the enzyme be affected? What if the meat was coated with the tenderizer and then immediately placed in a hot oven, how would the enzyme be affected? 8. You decide to make some Jell-O to impress your grandma when you go to her house for dinner; you add some fresh pineapple (her favorite fruit) to the mix. You put it in the fridge and think about how happy she will be when you visit tomorrow. When you wake up and look at the Jell-O it is all still liquid with pineapple chunks on the bottom. You go to Grandma’s house without a dessert. Not to be outdone, your little sis decided to make dessert for Grandma too. She carefully follows the directions on the package and makes raspberry Jell-O with canned pineapple and arrives with a perfect dessert for lunch. After doing some research you discover that Jell-O is made from gelatin (which is an animal protein) and that pineapple contains an enzyme called bromelain that can break down animal proteins. Why did the fresh pineapple cause this reaction and the canned pineapple not? 9. Lactase is an enzyme that breaks down lactose sugar in your stomach to form glucose and galactose. Some people are lactose intolerant. A product known as Lactaid was created to help this problem. These pills are taken as an artificial form of the enzyme prior to eating foods high in lactose sugar. The Lactaid will break the lactose apart which prevents the problems of lactose intolerance for those missing the enzyme naturally. An experiment was set up to test how lactaid works. Use the information given to predict the outcome in each test tube. An enzyme solution was created by mixing Lactaid tablets with water. This is Enzyme A. Some of this solution was placed in a test tube and boiled. This is Enzyme B. Whole milk is the source of lactose sugar Table sugar dissolved in water is the source of sucrose sugar Five test tubes were set up as below. After a few minutes each test tube was tested to see if glucose was present (note: glucose will be present if the disaccharide sugar is able to be broken apart into the monosaccharide sugars) . Test tube 1 – Milk (lactose)+ enzyme A Test tube 2 – Milk (lactose) + water Test tube 3 – Milk (lactose) + enzyme B Test tube 4 – sucrose + enzyme A Test tube 5 – sucrose + water Predict what you think will be the result of each test tube and explain why. Test Tube 1 Test Tube 2 Test Tube 3 Test Tube 4 Test Tube 5 Glucose (Yes or No) Why or Why Not? 10. Look up each of the following diseases and explain how they are related to enzymes. Galactosemia Tay-sachs PKU 11. Using the internet, find 2 additional uses for enzymes other than their uses in the body. Lesson 12: Lion vs. Elephant Digestion Lab Every animal obtains food. Why? Is it only to satisfy their hunger? Lion Digestion In a zoo, the lion is given beef to eat. When proteins are digested, chemical bonds between each amino acid are broken. In a group of 4, each student will have one of the four proteins found in the beef that a single lion has eaten. You will cut the protein into individual amino acids (chemical digestion) so that they can be taken into the circulatory system through the small intestine (nutrient absorption). Get your protein and determine how many bonds are holding it together. __________________ STOP: Get question 1 checked by your teacher before moving onward. Teacher initials: _____________ Cut your protein into individual amino acids. How many total cuts did you make? _____________ Proteins needed for lion survival: Using the amino acids from the proteins you broke down and “digested” in your group, create the NEW proteins listed below that are needed for lion survival. To build each new protein, arrange amino acids in a straight line. Protein for muscle Protein for collagen Protein for fur Protein for cell transport LYS GLU LYS THR LYS ALA PHE PRO SER ALA GLU GLU GLU GLU HIS THR VAL LEU VAL PHE VAL SER VAL LYS VAL ARG PHE VAL SER VAL VAL LEU ASN PRO VAL PRO ILE LYS LEU LYS CYS PRO PRO LEU HIS GLY ARG VAL PRO LYS LYS ALA SER HIS PRO ASN THR Some enzymes break things down while others build things up: When an organism digests food, chemical reactions inside the body take place where the breaking and forming bonds occur. In these processes, there are enzymes that catalyze the breakdown of food, and there are other enzymes that catalyze the forming of bonds to build larger molecules for the cells and body. The scissors you use today represent a catabolic enzyme where the tape or glue used to rebuild proteins for the lion represent anabolic enzymes. In this example, the enzymes are forming bonds between the amino acids which results in a new protein. Once all of these chemical reactions take place, there is a net release of energy that can be used in the cells of the body. Questions: Fill out the following data table. In this model, when a peptide bond is broken from a protein source, 10 kcal of net energy is released. Protein (Original) Number of Bonds Broken (cuts) Amount of Energy (kcal) 1 2 3 4 Total: Are there amino acids left over from your original protein? YES or NO If yes, which ones? Were any of your original amino acids “swapped” with someone else in your group? Give specific evidence. Fill out the following data table. In this model, it takes approximately 10 kcal of energy to form a peptide bond in the new protein. Data Table 2 Protein (new) Number of Bonds Formed Amount of Energy (kcal) muscle collagen fur Cell transport Total: What is the net gain of energy when going from the bonds broken in Data Table 1 above to forming new bonds in new proteins in Data Table 2? ______________________ How could the lions use this net gain of energy based on what you have figured out in previous lessons? Elephant Digestion The elephant’s diet consists of plant material which is high in cellulose, which is a carbohydrate. Collagen is a protein found in skin. Skin cells are replaced every 2 weeks. The elephant needs collagen to replace and/or repair these skin cells. As a group, complete the following: Analyze the cellulose molecule model on the next page. Step 1 illustrates the elephant eating plant material and then magnifies it at the molecular level. a. What overall process is occurring from step 1 to step 3? ________________________________ b. What happens between step 2 and step 3? ________________________________ The single molecules are small enough to be absorbed from the digestive tract into the blood. From there they can be carried to parts of the body where they can be used to make larger molecules again or be broken down for energy. Conclusion Questions: Explain the relationship between digestion time and the length and complexity of the elephant’s digestive tract. What element is missing in the cellulose model needed to make proteins like collagen? __________________________ Since the elephant’s diet consists of plant material only, where would the elephant get the missing element needed to make collagen (or any protein)? Explain the relationship between bonds broken, digestion time, and the length of the digestive system in an herbivore vs carnivore. What was the missing element (from Step 5 in the cellulose model) that is needed to make proteins like collagen? The Nitrogen Cycle After analyzing the above diagram, what organisms are able to turn unusable nitrogen (N2) from the air into a form usable for plants (NO3-)? Highlight these organisms in the diagram. Why do plants need to obtain usable nitrogen (NO3-)? **Hint: Look at your Macromolecules: What are the building blocks of life? Worksheet When an organism excretes waste, can a plant directly use it as fertilizer (nitrogen source)? Use information from the diagram to support your answer. Look up and define the term mutualism. Are there any mutualistic relationships found in the above diagram? Put a box around this example. Explain what is happening in the mutualistic relationship in question #5. In the midwest, the two most common crops grown are corn and soybeans. Corn is a crop that depletes the soil of nitrogen. Soybeans are a crop that have symbiotic bacteria living on their roots. How do farmers use this information when they plan out their crops from one year to the next? How does nitrogen get into the food web? How does an elephant get its source of nitrogen to create the proteins it needs? How would a lion get its source of nitrogen to create the proteins it needs? Draw a lion in the Nitrogen Cycle Diagram on the previous page. Be sure to draw appropriate arrows! MACROMOLECULE & ENZYME KEY POINTS Carbon is the essential element for life. Must always make ______ bonds. Monomers are ___________________ Polymers/Macromolecules are _______________________________ Process of Building Molecules is called ________________________ - Water is ___________ Process of Breaking Molecules is called _______________________ - Water is _____________ The greater number of Carbon = ________________ energy ATP is the cell's _____________________ energy molecule. CARBS LIPIDS PROTEINS Picture Elements Uses Names/Examples Foods high in this type of macromolecule Other ENZYMES Are a specific type of ______________________ Cause a reaction to __________________ by _______________ the activation energy necessary for a reaction to occur Each enzyme has a specific shape that matches its _________________. The enzyme and substrate fit together in a location called the ___________________________ Changing the shape of the enzyme means that the enzyme is __________________ and will no longer function Things that can cause an enzyme to denature: _______________ and ______________ Lesson 13: Creating Chains and Webs to Model Ecological Relationships OVERVIEW You will identify producers and consumers in the savanna ecosystem of Gorongosa National Park in Mozambique. Using a set of “Gorongosa cards,” you will then create a food chain to show the flow of energy in that system. You will then construct a more complex model of the flow of energy by depicting multiple relationships in a food web and make a prediction about the impact of introducing some kind of disturbance (non-organism cards) that may impact the ecosystem. Key Vocabulary: Define the following terms Producer: _____________________________________________________________________________________ Consumer: ___________________________________________________________________________________ Primary Consumer: _____________________________________________________________________________ Secondary Consumer: ___________________________________________________________________________ Tertiary Consumer: ______________________________________________________________________________ Apex Predator: _________________________________________________________________________________ Energy Pyramid: _______________________________________________________________________________ Trophic Level: _________________________________________________________________________________ Food Web: ____________________________________________________________________________________ 10% Rule: ____________________________________________________________________________________ INSTRUCTIONS You will receive a set of cards that depict some common animals, plant types, and ecological forces or disturbances from the savanna ecosystem in Gorongosa. Use the cards to build models and answer questions as directed on this worksheet. After building a food chain or food web with the cards, record your version by writing the organism names in the appropriate spaces on the worksheet and connecting them with arrows. Part 1: Creating a Food Chain Using only the organism cards, sort them into two piles that represent producers and consumers. 1. How many producers do you have? _________ 2. How many consumers do you have? _________ 3. A food chain is a model that identifies the feeding relationships and the flow of energy in an ecosystem. Select a producer and a consumer from your piles, then fill in the blanks below and select which model (A or B) correctly shows the flow of energy by circling the correct option below. A. _______________ → _______________ Consumer Producer or B. _______________ → _______________ Producer Consumer 4. Justify why you chose A or B as the correct model. 5. Select four cards to create a food chain, starting with a producer. Label the trophic level of each organism in your food chain as follows: producer, primary consumer, secondary consumer, tertiary consumer. Record your food chain in the space below using species names and arrows. Part 2: Available Energy at each Trophic Level Only a small fraction of energy available at any trophic level is transferred to the next trophic level. That fraction is estimated to be about 10 percent of the available energy. The other 90 percent of the energy is needed by organisms at that trophic level for living, growing, and reproducing. That energy is lost as heat to the environment. This relationship is shown in the energy pyramid shown here. It suggests that for any food chain, the primary producer trophic level has the most energy and the top trophic level has the least. 6. Why is a pyramid shape like the one shown an effective model for quantifying energy flow? 7. Place the organisms from your original food chain on the pyramid provided below. 8. Using the rule of 10 percent in energy transfer, calculate the amount of energy available at each level if your producer level had 3,500,000 kilocalories of energy/area. 9. In one or two sentences, describe how the available energy may affect the population sizes of organisms at different trophic levels. Energy Pyramid Practice Directions For each energy pyramid: Place each organism in the correct trophic level. Calculate the amount of energy available at each level using the 10% Rule. Answer the question. 1. Prairie Ecosystem Organisms Hawk Grass Mouse Snake Energy from the Sun: 500,000 Calories Complete the pyramid. Question: Explain why the hawk receives so much less energy than the grass. 2. Ocean Ecosystem Organisms Shark Phytoplankton Tuna Zooplankton Energy from the Sun: 800,000 Calories Question: If the shark population suddenly increased, how might this affect the tuna population? 3. Forest Ecosystem Organisms Oak Tree Caterpillar Blue Jay Hawk Energy from the Sun: 1,000,000 Calories Question: Which organism receives the most energy? Explain why. Food Web Practice #1: African Savanna Directions Read the description below carefully. Use the information provided to draw a food web showing the flow of energy. Use arrows to show the direction that energy moves (from the organism being eaten to the organism that eats it). Then answer the questions below. African Savanna Ecosystem The African savanna is home to many different organisms that depend on one another for survival. The acacia trees, savanna grasses, and wildflowers capture energy from the Sun and make their own food through photosynthesis. Grasshoppers feed on grasses and wildflowers. Mice eat grass seeds and insects. Zebras graze on grasses, while giraffes browse the leaves of acacia trees. Elephants eat grasses, leaves, bark, and shrubs. Impalas feed on grasses and leaves. Snakes hunt mice and grasshoppers. Jackals eat mice, grasshoppers, snakes, and young impalas. Secretary birds hunt snakes and large insects. Lions prey on zebras, impalas, young elephants, and sometimes giraffes. Leopards hunt impalas, jackals, and mice. After animals die, vultures feed on the remains left behind by predators. Questions 1. Identify one organism from your food web that fits each category. Category Organism Producer Herbivore Primary Consumer Secondary Consumer Tertiary Consumer Apex Predator 2. If a disease greatly reduced the zebra population, explain how this change could affect two other organisms in the food web. Food Web Practice #2: Temperate Forest Directions Read the description below carefully. Use the information provided to draw a food web showing the flow of energy. Use arrows to show the direction that energy moves. Then, answer the questions below. Temperate Forest Ecosystem In a temperate forest, oak trees, maple trees, berry bushes, and forest grasses are producers that capture energy from sunlight. Caterpillars feed on leaves from trees and bushes. Rabbits eat grasses and young plants. White-tailed deer browse leaves, grasses, and shrubs. Squirrels eat acorns, seeds, berries, and mushrooms. Field mice feed on seeds and berries. Frogs eat insects such as caterpillars. Snakes hunt frogs, mice, and squirrels. Owls prey on mice, squirrels, frogs, and snakes. Foxes hunt rabbits, mice, squirrels, and frogs. Bobcats hunt rabbits, squirrels, foxes, and deer fawns. Coyotes prey on rabbits, mice, squirrels, and deer fawns. When plants and animals die, fungi break down the dead material and return nutrients to the soil. Questions 1. Identify one organism from your food web that fits each category. Category Organism Producer Herbivore Primary Consumer Secondary Consumer Tertiary Consumer Apex Predator 2. Choose one food chain from your food web that contains at least five organisms. Write the food chain below and identify the trophic level of each organism. Example format: Producer → Primary Consumer → Secondary Consumer → Tertiary Consumer → Apex Predator