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Classroom Cell Communication Summary In this lesson, students will act out cell communication using the classroom and desks as cell and nuclear membranes. The students will be acting as ligands, membrane proteins and signal transductions proteins, and they will perform the actions of these ligands and proteins through a signal transduction pathway. The students will be exploring a basic set up of a signal transduction pathway, which will be followed by the students creating their own, more elaborate analogy based on real examples. Through this activity, the students will understand the processes that are involved in cell-to-cell communication and signal transduction pathways. General Background Information There are 3 phases of signal reception, Reception, Transduction, and Response. A signal ligand (hormone or environmental stimulus) will bind to a receptor protein on the cell membrane. The binding to the receptor protein will initiate a transduction of the outside signal through the cytoplasm via secondary messengers and relay proteins to initiate a cellular response. The cellular response can be within the cytoplasm or within the nucleus. The signals can be sent over short distances (direct contact) or over long distances (via the blood stream). Some signals that are nonpolar may enter the cell without reception and act directly in the nucleus. There are three major signal transduction pathways: G-Protein Linked Reception, Tyrosine Kinases, and Ligand-gated Ion Channels. Common second messengers within the cell are Cyclic AMP and Ca2+. Within the cell, the outside signal can be amplified through a phosphorylation cascade. The signal can also be amplified by scaffolding proteins that will initiate multiple cellular responses. It is important to note that the cellular response in one cell from a specific ligand may be different from a cellular response in a different cell from the same ligand. Key Concepts • Ligand binding • Signal transduction • Cellular response Objectives • Observe and identify the aspects of cell-to-cell communication, ligand binding, signal transduction, and cellular response. • Record the specific details of the various pathways presented by each student group, following the example modeled by the class. • Demonstrate how a ligand works. • Demonstrate how signal transduction occurs via primary and secondary messengers as well as signal amplification. • Communicate how specific examples of cell-to-cell communication work. Materials • Desks to represent plasma and nuclear membranes • Students to represent signaling molecules, receptor proteins, proteins of signal transduction, and those of a cellular response. • Two notecards on which to write a message. Procedure Part 1. – Basic cell-to-cell communication and signal transduction pathway. Set up: 1. Have the students create a circle in the classroom made out of desks. Inside of the circle have the students make a smaller circle of desks. The large circle will represent the cell membrane and the smaller circle will represent the nuclear membrane. The desks that make up the nuclear membrane should have spaces between them to represent nuclear pores. 2. One student should sit at a desk in the outer circle. The student will act as a receptor protein. 3. Four students should be inside of the cell membrane, but outside of the nuclear membrane. Three of these students will act as the proteins within the Transduction pathway. Designate the students ahead of time as, protein 1, protein 2, protein 3, and the fourth will act as a ribosome. 4. Three students should be waiting in the nucleus. One will act as a transcription factor, one will act as DNA, and the other as RNA. Designate them ahead of time. 5. An additional three students should be within the cell membrane, but positioned off to the side. They will act as proteins to initiate the cellular response. 6. The teacher will act a ligand, sending a message to the classroom cell 7. See the following diagram for set-up. Transduction: 1. Sitting at their desk, or in a location a few feet away from the teacher desk, the teacher will begin by writing a note on the note card. This note will be the instructions to the cellular response that will be passed on to the classroom cell. Ex. “elongate in one direction towards the teacher’s desk.” 2. The teacher (ligand) will hand the note card to the person sitting in the desk on cellular membrane (protein receptor). 3. Once the protein receptor receives the notecard from the ligand, one student (protein 1 within the signal transduction pathway) from within the cell will move towards the receptor protein and take the notecard. 4. That student will then hand off the note card to a second student (protein 2 within the signal transduction pathway) in the cytoplasm. The second student will then hand the notecard to the third student (protein 3 within the signal transduction pathway) in the cytoplasm. 5. Protein 3 will walk the notecard through the nuclear membrane and deliver the notecard to the student designated as the transcription factor. 6. The transcription factor will deliver the note card to the student designated as the DNA. 7. The DNA should read the card and rewrite it on a different notecard. This will represent transcription. The new notecard will be handed to the student designated as RNA. 8. The RNA will bring the notecard through the nuclear membrane and carry the notecard to the student designated as the ribosome. 9. The ribosome will call in the proteins from the side of the cell and hand the note card to them. This will represent 10. The proteins will then start to push the cell membrane towards the teacher’s desk. Part 2. – Specific example of cell communication, For rest of the class time and homework, divide the class into 8 groups of students. Have each group research one of the following topics by using the links below or through any means they wish to pursue. The next day in class, the students will use the model demonstrated in class to walk the class through the example with which the have been assigned. Students may want to bring in additional props that may be needed, such as something to represent phosphates or ATP. Topics that should be covered in the student presentations are below. G Protein Coupled Receptors Receptor Tyrosine Kinases Ion Channel Receptors (ICR) Protein Kinase A (PKA) Cyclic AMP Hormones and Intercellular Receptors Phosphorylation Cascades Calcium Specificity Specific Examples from which to choose: Topic Topics to be covered Where to Find Info Mating Factor (Shmoos) G Protein Coupled Receptors Campbell Text Death Signal (Apoptosis) Campbell Text Growth Factor Phosphorylation Cascade Campbell Text IP3 associated pathway G Protein Coupled Receptors & Campbell Text Calcium Epinephrine G Protein Coupled Receptors, Knuffke Prezi Adenylyl cyclase, cAMP, & PKA Long term Memory ICR, Calcium, Adenylyl cyclase, HHMI Video cAMP, & PKA Insulin Tyrosine Kinase Receptor Tyrosine Kinases Wikipedia Link Testosterone Hormones and Intercellular Campbell Text Receptors Assessment Students will be assessed on their group’s presentation and the knowledge that they show through questions that they ask or the teacher may them throughout the presentations. • Performance 1. Students will need to act out the signal transduction pathway that they have been give to demonstrate understanding to the class and to the teacher. • Product Students may produce a small video that they will upload to the class web site for further study. • Assessment An assessment will not be given in this lesson, but a unit quiz will be given at the end. Additional Resources • http://prezi.com/okvybidzh1ts/ap-bio-cells-5-communication/ - David Knuffke • http://www.dnatube.com/video/5704/Cell-Communication - DNAtube • http://www.youtube.com/watch?v=xnGXItWrJ3k&feature=youtu.be&noredirect=1 - Paul Anderson • http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/CellSignaling.html - J Kimball • http://www.wiley.com/college/pratt/0471393878/student/animations/signal_transduction/- Signal transduction animation exercise • http://media.hhmi.org/hl/08Lect4.html - Eric Kandel, M.D. • http://en.wikipedia.org/wiki/Insulin_receptor - Insulin tyrosine kinase • Reece, Jane B., et al. Campbell Biology. 9th edition; International edition. Harlow: Pearson Education, 2011. Science Standards Next Generation Science Standards HS. Structure and Function HS-LS1-1. Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins, which carry out the essential function of life through systems of specialized cells. Massachusetts Science and Technology/Engineering Curriculum Framework I. Content Standards 1. The Chemistry of Life Central Concept: Chemical elements form organic molecules that interact to perform the basic functions of life. 1.2 Describe the basic molecular structures and primary functions of the four major categories of organic molecules (carbohydrates, lipids, proteins, nucleic acids). 1.3 Explain the role of enzymes as catalysts that lower the activation energy of biochemical reactions. Identify factors, such as pH and temperature, that have an effect on enzymes. 2. Cell Biology Central Concepts: Cells have specific structures and functions that make them distinctive. Processes in a cell can be classified broadly as growth, maintenance, and reproduction. 2.1 Relate cell parts/organelles (plasma membrane, nuclear envelope, nucleus, nucleolus, cytoplasm, mitochondrion, endoplasmic reticulum, Golgi apparatus, lysosome, ribosome, vacuole, cell wall, chloroplast, cytoskeleton, centriole, cilium, flagellum, pseudopod) to their functions. Explain the role of cell membranes as a highly selective barrier (diffusion, osmosis, facilitated diffusion, active transport). 2.2 Compare and contrast, at the cellular level, the general structures and degrees of complexity of prokaryotes and eukaryotes. 3. Genetics Central Concepts: Genes allow for the storage and transmission of genetic information. They are a set of instructions encoded in the nucleotide sequence of each organism. Genes code for the specific sequences of amino acids that comprise the proteins characteristic to that organism. 3.2 Describe the basic process of DNA replication and how it relates to the transmission and conservation of the genetic code. Explain the basic processes of transcription and translation, and how they result in the expression of genes. Distinguish among the end products of replication, transcription, and translation. II. Scientific Inquiry Skills Standards SIS1. Make observations, raise questions, and formulate hypotheses. • Observe the world from a scientific perspective. • Pose questions and form hypotheses based on personal observations, scientific articles, experiments, and knowledge. • Read, interpret, and examine the credibility and validity of scientific claims in different sources of information, such as scientific articles, advertisements, or media stories. SIS4. Communicate and apply the results of scientific investigations. • Develop descriptions of and explanations for scientific concepts that were a focus of one or more investigations. • Review information, explain statistical analysis, and summarize data collected and analyzed as the result of an investigation. • Explain diagrams and charts that represent relationships of variables. • Construct a reasoned argument and respond appropriately to critical comments and questions. • Use language and vocabulary appropriately, speak clearly and logically, and use appropriate technology (e.g., presentation software) and other tools to present findings. • Use and refine scientific models that simulate physical processes or phenomena.