Exploring Cells: Essential Concepts and Activities for Understanding Life

1. Unit 1: Cells

2. Essential Questions • What makes something “alive”? • What are cells and what do they do? • How are organisms organized? • How do substances move in and out of cells, and how are they transported to the rest of our body? • What are enzymes and how do they help our body function? • How are organic molecules used in our body?

3. Day 1 • Required Readings: • Section 2.1: Cells and cell structures • Learning Objectives: • The basic unit of living organisms is the cell • All cells have certain features in common, but there are differences between plant and animal cells • The study of cells requires the use of a microscope

4. Starter • There are some microscopes set up with different cells at the back. • In your group, go to each station and observe the different slides. I will tell you when time is up and to switch to the next station. • Write down what you observe on the different slides. Be sure to label them. • When back in your seats, discuss with your group the similarities and differences between the slides. • Time: 15 minutes

5. Activity One: What is a Cell? • Observe the dish that has been placed on your desk. • Is it a living being? • Why or why not? • What makes something a living thing? • Brainstorm with your group features/characteristics that are common to all living things. • What is a cell? • What features/functions does a cell have? • Time: 15 minutes

6. Activity Two: What are the different types of cells? • Look at the pictures provided and point out any similarities and differences between the three types of cells. • What structures can you see? • Time: 15 minutes

7. Activity Three: Prokaryote vs. Eukaryote • The pictures you were just looking at were examples of prokaryotic cells and eukaryotic cells. • What do these words mean? • Create a table to distinguish the difference between prokaryotic and eukaryotic cells • Time: 15 minutes

8. Activity Four: Plant Cells vs. Animal Cells • Create two different slides: • One of an onion cell • One of a cheek cell • Draw what you see in both of them • Use the following pictures to help you with the following questions • Compare and contrast the two different types of cells • What features do they have in common? What features are different. • Time: 30 minutes

9. Animal and Plant Cells

10. Homework: • Complete the “Cell as a City” • Label the plant and animal cell

11. Day 2: Organization of Living Things • Required reading: • Section 2.2 • Learning Objectives: • To understand that the body of a living organism is a highly organized structure • To understand that cells, tissues, organs and systems represent increasing degrees of organization in living organisms • The structure of cells relate to its function; cells are specialized

12. Starter • Draw a pyramid and place these words in the pyramid from smallest (bottom) to largest (top) • Cell • Organism • Organ • Molecule • Tissue • Atom • Organ system • Time: 10 minutes

13. Activity One: Review Cell Organelles • Get in a group with 2-3 other people who you do not sit with • Compare your answers from the “Cell as a City” and labeling homework. • Discuss any discrepancies between your answers and try to come up with answers together for any you left blank. Do not copy answers • Time: 20 minutes

14. Activity Two: How are organisms organized? • You have put the levels of organization in order from smallest to largest, but what does each one mean? • In your group, come up with an explanation for each term using an example: • Organelle, cell, tissue, organ, organ system, organism • You can represent your information in any way you like • Time: 20 minutes

15. Activity Three: • Use your text book and microscope slides at the back to help you determine why different cells are shaped differently (cell specialization) • Describe how the structure (how it looks) of the following cells relates to its function (what it does) • Red blood cell • Nerve cell • Muscle cell • Root hair cell • Xylem vessel • Time: 30 minutes

16. Closing Activity • Explain the following situations: • Why do muscle cells have more mitochondria than other types of cells? • Why do leaves in plants contain a lot of chloroplasts? • Where would you find a lot of ciliated cells? Why? • Time: 10 minutes

17. Homework • None for tonight!

18. Day 3: Movement in and out of Cells • Required Reading • 2.3 Movement in and Out of Cells • Learning Objectives: • To understand that the contents of a living cell must be kept separate from its surroundings • To know that the cell surface membrane can act as a barrier to some substances which might pass between a cell and its surroundings • To understand the principles of diffusion, osmosis, active transport and phagocytosis

19. Starter • Give an example of diffusion or osmosis. • Is this system in equilibrium? Why or why not? If it is not in equilibrium, draw how it would look in equilibrium. • Time: 10 minutes

20. Activity One: Observing Diffusion • Observe the beaker that has been placed on your desk • Describe what you see • Write down any questions that you have about what is happening • Discuss in your group what is happening and why using the following terms: • Diffusion • Concentration gradient • Movement of particles • Time: 10 minutes

21. Activity Two: The structure of the cell membrane • Cell membranes are often described as a “fluid mosaic” • What does this mean to you? • Why do you think this would be used to describe the cell membrane? • Create a model of the cell membrane using the cut-outs provided • Time: 30 minutes

22. Activity Three: osmosis is the diffusion of water particles • Osmosis is a special type of diffusion involving water particles • We will model this by putting decalcified eggs (the “cell”) into water, salt and sugar solutions to observe the net movement of water particles • Use the experimental design sheet to plan out your experiment • Show me when completed and set up your practical • Time: 35 minutes

23. Homework • Draw a picture of an animal cell and a plant cell • Show what happens when the cells are placed in a hypertonic, hypotonic and isotonic solution

24. Day 4: Movement in and Out of Cells (Cont’d) (60 minutes) • Required Reading • 2.3 Movement in and Out of Cells • Learning Objectives: • To understand that the contents of a living cell must be kept separate from its surroundings • To know that the cell surface membrane can act as a barrier to some substances which might pass between a cell and its surroundings • To understand the principles of diffusion, osmosis, active transport and phagocytosis

25. Starter • What is the difference between active and passive transport? • Use a picture to explain how active transport is achieved • Give an example of active transport in the body • Time: 10 minutes

26. Activity One: Results from egg lab • Obtain the masses from your eggs and record your results • CERR lab report due September 4 • Extension activity (include at the end of report): • Bodies of water have different salinities (salt concentrations) • See wiki for full instructions • Time: 20 minutes

27. Activity Two: Observing Osmosis and Diffusion • We will be completing the “Examining Cellular Transport” lab activity • Read over the instructions with your lab group • Set up your materials and begin the practical • Time: 25 minutes

28. Homework • Complete the Examining Cellular Transport lab packet • Due September 6

29. Day 5: Enzymes Control Biochemical Reactions • Learning Objectives: • To appreciate that biochemical reactions in living organisms must be controlled • To understand how enzymes can act as biological catalysts • To list and explain factors that affect enzyme activity • To list some examples of human exploitation of enzymes

30. Starter

31. Starter • Chew on the crackers provided • Don’t swallow them until instructed to do so • What did you notice about how the taste changed when you were chewing? • What is happening here? • Time: 15 minutes

32. Activity One: Enzymes are biological catalysts

33. Activity One (cont’d) • Discuss the following questions with your group: • What is an enzyme? • How do they work? • What conditions do they work best in? (Hint: Think about pH, temperature, etc.) • Where do we find enzymes? • What are some examples of enzymes? • How can we identify if something is an enzyme (Hint: Think of how they are named) • Time: 20 minutes

34. Activity Two: Creating an enzyme • Using the plasticine create a step-by-step model of how an enzyme works • Include the following: • Enzyme with active site • Substrate • Enzyme-substrate complex • Product • Draw the steps on your cue cards • Time: 25 minutes

35. Activity Three: How does an enzyme work? • In your group, use the large paper to create a graph that represents the rate of a reaction in our body and how enzymes work to make them faster • On your graph, include how temperature and pH can also affect the enzyme activity and how they play a role in the reaction rate • Time: 25 minutes

36. Homework • Work on Egg Lab (CERR model) – due September 6 • Work on Cellular Transport Questions – due September 6

37. Day 6 • Required Readings: • 2.5: Humans use enzymes from microorganisms • Answer questions posted on Wiki • Learning Objectives: • To understand that enzymes have many roles which benefit humans • To know examples of range of uses of enzymes • To understand the benefits of enzyme immobilization

38. Starter • How do we use enzymes to benefit our daily lives? • Discuss in your group any questions you have about the Egg lab write-up • Time: 15 minutes

39. Activity One: Using Enzymes • You are going to be researching some different ways that people use enzymes from microorganisms to benefit our every day lives • You will choose how you would like to present your data and then work with a group of others who would like to present the data in the same way: • Write a story, song or poem • Create a documentary • Make a powerpoint • Create a table and/or graph presenting the data you collected • Time: 45 minutes for research

40. Activity One (cont’d) • The following items must be included in your presentation: • How are enzymes used in pharmaceutical production? • How are enzymes used for biological washing powders? • How are enzymes used in food production? • How are enzymes used in textile production? • Time: 30 minutes

41. Activity Two: Making your presentation • After you have collected the information you need,work in your group to make up your presentation • There are two computers in the back for your use • Time: 30 minutes

42. Activity Three: Presenting your findings • Present to the class your findings • Time: 15 minutes

43. Homework • Egg lab – due Thursday • Cellular transport questions – due Thursday

44. Day 7: Enzyme experiments and the scientific method • Required readings: • 2.6: Enzyme experiments and the scientific method • Learning objectives: • To understand how enzymes can work as biological catalysts • To understand and apply the scientific method

45. Starter • In this lab, we will be using the enzyme catalase (from potatoes) to break down hydrogen peroxide (H2O2) • Write a balanced chemical equation for the break down of hydrogen peroxide • What are the different variables we could test in this lab? Your text mentions one way. Come up with at least 2 more ideas. • Time: 15 minutes

46. Activity One: Planning for the experiment • For this lab, you can choose the variable you wish to test: • pH • Temperature • [Catalase] • We will time how long it takes for a disc soaked in the catalase to float to the top of the hydrogen peroxide solution • Time: 5 minutes

47. Activity Two: Recording your results Create a table to record your results in Time: 10 minutes

48. Activity Three: Performing the experiment • When your group is ready, go to the back and complete the practical • Clean up when you are finished • Time: 45 minutes

49. Closing and Homework • You will complete a CERR model lab report for this lab – due Wednesday, September 12 • If you assigned sections for the last lab write up, make sure you change around who is doing what

50. Day 8: All living things are made up of organic molecules • Required Readings: • 2.7 • Questions from wiki • Learning Objectives: • To understand that the structures of living things depend on the molecules that make them up • To list the types of molecules found in living organisms