Biology of the Animal Cell

Section: Animal Science Unit: Unit 5: Cell Structure and Function Lesson Title: Lesson 3: Biology of the Animal Cell 2 “Setting Our Cytes Ahead” Student Learning Objectives As a result of this lesson, the student will: 1. Describe cellular organelles and their functions. 2. Select and use appropriate technologies to gather, process and analyze data, and report information related to an investigation. Time Instruction time for this lesson 50 minutes. Resources/References  Cells Alive CD-ROM (available online at www.cellsalive.com)  An Illustrated Guide to Veterinary Medical Terminology, Janet Amundson.  The Biology Coloring Book, Robert Griffen  Clinical Anatomy and Physiology for Veterinary Technicians, Thomas Colville.  Biology, 4th edition, Cambell, 2000  Agripicture.com by Peter Dean Tools, Equipment, and Supplies Handouts Colored Pencils Calculators Key Terms Plasma membrane Chromatin Ribosome Microfilament Golgi apparatus Lysosome Cell wall Nucleus Microtubule Endoplasmic reticulum Flagella Mitochondria Chlorophyll Cytoskeleton Cytoplasm Cilia Vacuole 1 Interest Approach Have the PowerPoint, “Setting your Cytes Ahead,” 2 on the screen when you begin. Start by reviewing the previous two lessons. As we continue our lesson on the parts of an animal cell, let’s review why cells are so amazing. Ask the following questions: 1. Raise your hand if you can tell us what cells determine in animals? Answer: Physical shape, conformation, size of tissue How meat will taste. Cells determine what kind of disease is present in animals. 2. Who can list the functions of animal cells? Answer: They are the smallest unit of a living system. They are vital to all life functions. They hold the blueprints of how an animal is put together They can reproduce. They can change the physical form of an animal, good and bad. 3. What are the two different kinds of cells and how are they different? Answer: Prokaryote and eukaryote Eukaryotic cells have internal membrane-bound organs, the largest of which is called the nucleus. Made up of one or more cells. Prokaryotic cells are single celled and lack internal membrane structures. 4. How big are animal cells? Answer: From .05 centimeter to 20 nanometers 5. What could it mean if you have an increased white blood cell count? Answer: White increase could mean an infection is present. 6. What is the function of the cell’s nucleus? Answer: Controls cells function. Holds the entire DNA or blueprints of how the organism is made. Excellent job! I am impressed at what you know. If some of you feel like this is not making sense, or you are not sure of the answers, you need to go back and visit some of your notes because you can expect to see these questions again on a future test. 2 Summary of Content and Teaching Strategies Objective 1. Describe cellular organelles and their functions. Ask the students to take out their cell coloring handout from Cell Biology 1. Distribute the student worksheet for Cell Biology 2, and ask the students to color the parts of the cell when asked in the presentation. Make sure each student has student lecture worksheet # 2 and colored pencils. Okay, now let’s finish looking at the cell and it’s functions. Remember the idea of the cell being compared to the restaurant? Well, we said the doors and walls represent the cell’s plasma membrane, which only allows certain materials to enter and exit the cell. The manager’s office of a restaurant is like the cell manager’s office called the _____ (wait on the class to answer). Right! The answer is the nucleus, which manages the cell’s functions and contains the DNA or genetic information of the entire organism. We also learned that cells have a fluid-like substance inside their plasma membrane where all the cell’s organs can move to perform their functions. This is called the cytoplasm. This is comparable to the rooms and hallways of the restaurant. Now let’s continue our lesson on the biology of the animal cell as we learn more about the other parts of the cell and how they operate. Go through the PowerPoint presentation slide by slide. Make sure you give enough time for each student to fill in the lecture outline and color each organelle when asked. Get familiar with the material before you begin so you might field questions or give added examples as you go. Click on the first slide. Go through the entire slide presentation. Show Slides 1-3 - Setting our Cytes Ahead, Part 2 These slides review information from the previous two lessons. Show Slide #4 - Structures for assembly and transport of proteins We continue the structures of the cells by looking at the structures for assembly and transport of proteins. We already mentioned the cytoplasm yesterday. Much of the cytoplasm is occupied by the endoplasmic reticulum. Show Slide #5 – Endoplasmic Reticulum The ER functions as the cell’s delivery system, much like the trucks that deliver raw products such as beef, vegetables and beverages to the steak restaurant. To make dinners at our restaurant, these raw products must be assembled on the counter in the restaurant. Show Slide #6 - Endoplasmic Reticulum This is a visual reference of the endoplasmic reticulum. 3 Show Slide #7 - Endoplasmic Reticulum The endoplasmic reticulum is a system of folded sacs extending throughout the cytoplasm. Rough ER has ribosomes on the outer surface; smooth ER has no ribosomes. Show Slide #8 – What is the function of the ER? The ER is the site of protein synthesis, or where protein is made. Show Slide #9 - Color the ER on your cell now! Allow students 30-45 seconds to locate and color the endoplasmic reticulum on their cells. Show Slide #10 - Structures for Protein Storage After the protein is produced in the endoplasmic reticulum, the protein needs to be stored. These structures are the storage rooms of the restaurant. They are the Golgi apparatus, vacuoles, and lysosomes. Show Slide #11 - Golgi Apparatus Visual This is what the Golgi apparatus looks like within the cell. Show Slide #12 - Function of the Golgi Apparatus The function of the Golgi apparatus is to sort and package proteins from the ER. These protein vesicles are then either secreted or used internally. Show Slide #13 - Color the Golgi apparatus now! Allow students 30-45 seconds to locate and color the Golgi apparatus on their cells. Show Slide #14 - Function of Vacuoles In the restaurant kitchen, the vegetables and meats are stored in bins and containers. Cells have spaces called vacuoles for temporary storage of materials. Vacuoles often store food, waste and enzymes needed by the cell. Show Slide #15 – Vacuoles Visual This is what the vacuoles look like. Compare this to what storage bins might look like in the restaurant…can you imagine the similarities? Show Slide #16 - Color the vacuole now! Allow students 30-45 seconds to locate and color the vacuoles in their cells. 4 Show Slide #17 - Function of Lysosomes Lysosomes are enzymes that digest excess or worn out cell parts. They can dispense their contents into vacuoles to digest whatever is being stored. What similarity is there with a restaurant? The trash bins! We discard old or worn out equipment and supplies in the trash bin – the trash bin digests it! Show Slide #18 – Lysosomes Visual This is what a picture of the lysosomes looks like. Color the Lysosome now! Allow students 30-45 seconds to locate and color the Lysosomes in their cells. Show Slide #20 - “THE POWER HOUSE” The mitochondria are like of the electricity source of the restaurant. All functions—the stove, lights, music and refrigerator—depend on energy from the outlets located in the restaurant. The mitochondria provide the same service for the cell. Show Slide #21 - ENERGY TRANSFORMERS!! This is a visual of the mitochondria. It is able to transform raw materials into energy to run the cell! Show Slide #22 - Functions of the Mitochondria The mitochondria are the site of ATP (Adenosine Tri phosphate) production from respiration. This is also where food molecules are broken down to release energy! Show Slide #23 - Color the mitochondria now! Allow students 30-45 seconds to locate and color the mitochondria in their cells. Show Slide #24 - Structures for Support and Locomotion! Years ago, scientists thought cell organelles just floated around within the cytoplasm. Recently, scientists have discovered that there are tiny rods and filaments that can move and change to form a framework for supporting organelles. Show Slide #25 – Microtubules and Microfilaments! These tiny filaments and rods are composed of microtubules and microfilaments Microtubules are thin and hollow. Microfilaments are thin and solid. These filaments are not visible in your drawings, but they do exist! They are like the studs within the walls of the restaurant. Although you can’t see them, they serve a very important purpose in the structure and function of the wall. Show Slide #26 – Cytoskeleton Visual The next organelle is the cytoskeleton! 5 Show Slide #27 - Function of the Cytoskeleton This organelle provides strength, structure and support; maintains cell shape, and aids movement of organelles and intracellular materials. Show Slide #28 - Color the cytoskeleton now! Allow students 30-45 seconds to locate and color the cytoskeleton in their cells. Show Slide #29 - How do cells move? Cells move in two ways - by the use of cilia or flagella. Show Slide #30 - Cilia Cilia are short, numerous, hair-like projections from the plasma membrane. They move in a “wave” motion. The cilia move the cell by beating rhythmically. Show Slide #31 - Flagella Flagella function to move the cell by one long projection that moves in a whip-like motion. Cells that have flagella will only have one or two projections. Show Slide #32 - Can you guess how each of these cells move? Show Slide #33 - Color the cilia or flagella now! If they are not present, draw them onto your cell coloring. Allow students 30-45 seconds to locate and color the cilia or flagella in their cells. Review/Summary. Check understanding by calling on a few students to explain what organelles they saw and the function of each. Help them to review for the upcoming The Organelle is Right Quiz! It’s time to play…THE ORGANELLE IS RIGHT!! At this time, get out your Organelle quiz sheet that reads, “THE ORGANELLE IS RIGHT” All students will take the quiz!! You will receive points for all right answers!! ARE YOU READY? Advance Slide For 1 point, name this organelle. Advance Slide For 1 point, name this organelle. Advance Slide For 2 points name this organelle. Advance Slide For 3 points name this organelle. Advance Slide For 5 points name this organelle. Advance Slide For 5 points name this organelle. Advance Slide Final question worth 5 points! Advance Slide 6 EXCELLENT JOB! There were 22 possible points. Please pass in your quizzes and colorings for credit. Remember—cells are the smallest living units of an organism. They are small, but have an incredible amount of form to their function. Each organelle in the cell has specific functions for cell maintenance, work and reproduction. Each cell provides specific functions to assist the organism as a whole. Now does anybody have questions or clarification about the animal cell and its function? If so, answer, if not, move on to the laboratory session. Objective 2. Select and use appropriate technologies to gather, process and analyze data and to report information related to an investigation. We are now going to practice working with our microscopes and preparing slides so that we can view cell organelles. Remember, in order to see most organelles, we would need a microscope much stronger than those found here. However, let’s see what we can see by working on the Cheek Cell Lab. Students will be looking at their own cheek cells under a microscope. This lab will take around 30 - 40 minutes, depending on how many students and microscopes you have. Read through the lab before hand to get an idea of the procedure. Set up the lab before you begin the lecture so you can move right into the lab portion at the end of the last slide. Make sure there are plenty of supplies and everything is well marked! Give each student a copy of the laboratory handout, “What do your Cheek Cells Look Like?” To see first hand what your cells look like, we will examine one of your cells and you will draw a picture of the cell, label its parts and answer a few questions regarding the process and what you see. I’ll need your full focus as I model how this should be done. (Have steps and procedure up on the board for reference) Due to lack of enough lab tools and equipment and the fact that they can divide and conquer, keep students working in pairs. Go through the procedure worksheet step by step, modeling the way it is to be done. Emphasize safety and proper lab technique. At the end of your demonstration, tell the students to ask for help if they have questions. Remind them of the timeline and to complete the student lab worksheet and hand it in before the period is over, then clean up their station. See Teacher Notes page at the end of this lesson plan. Okay, you may begin! (Be on hand to watch and answer questions and monitor student work). After completing the lab, ask the following questions: What was the most difficult thing about this lab? 7 How many of you were able to see individual cheek cells? If you weren’t able to see them, what went wrong? Those of you who were able to see the cheek cells, what organelles were present? Why were some of the organelles not present? 8 Application Extended classroom activity: Pretend the classroom is a cell, with the walls being the cell membrane. Assign each student a cellular part. Have each student review the function of the cell and choose something within the classroom that could represent this organelle. Remind students that cell parts should be explained in relationship to other cell parts (other students). Have the class present the information to the group. FFA activity: Compare the functioning of the officer team to that of an effective cell. When cells do not operate in unison, then the organism can become sick. Similar happenings can occur from each person not operating as a team within the chapter. The perfect cell, or the perfect FFA chapter, operates when each has a purpose and a goal to accomplish. SAE Activity: Have students with livestock SAEs research the proper ways to collect and look at blood cells. Have students research diseases that effect the normal functioning of the cell (examples: mad cow disease or scrapie) and present this information to the class. Evaluation. Evaluate the student work on coloring the cell, and on “The Organelle is Right” Quiz. 9 Answers to Assessment: Answer key to the “Organelle Is Right” Quiz 1. 2. 3. 4. 5. 6. 7. Cell Membrane Mitochondria Nucleus Nuclear membrane Cilia Nucleolus Golgi apparatus 10 THE ORGANELLE IS RIGHTQUIZ Name: Write the correct name of the organelle on the screen. You will have 5 seconds to do so for each organelle. Good Luck! 1. 2. 3. 4. 5. 6. 11 Lab Procedures Cheek Cell Lab The purpose of this lab is to review basic cell biology and to identify specific cells through staining techniques. Objectives: 1. 2. 3. 4. 5. Understand the use of the microscope and its functions. List the materials used in preparation of wet mount slides. Prepare a slide and identify the cell through correct use of the microscope. Draw and label the parts of the cheek cell. Practice safe laboratory techniques while preparing slides. Introduction: Today we will examine your own cells. That’s right, your living cells. You are going to remove some cheek cells from the inside of your mouth. You will want to make sure you do not have food particles in the saliva when doing this. Rinse your mouth with water if you need to. You will then prepare a slide and observe the cell and its parts, then label each organelle. Procedure: 1. Gather all your materials and prepare your microscope. You will need: Slide Slide cover Methylene Blue stain, 1% Solution Swab Forceps Pencil and paper Microscope 2. Gently scrape the inside of your mouth with a swab several times with adequate pressure. This scraping will collect some of the cheek cells. 3. Place the cells on a clean slide (in center). i. Apply one drop of stain over the cells. ii. Place the slide cover over one end of the drop and gently drop the slide cover so that it lands on top of the sample. iii. Use the paper towel on one side of the cover to draw the excess stain from underneath the cover mount. This is called “wicking.” iv. Place the slide on the stage of the microscope. Adjust the microscope so you begin on the lowest power of magnification. Focus the slide. v. Now move to the next magnification and focus. vi. When you have a good image of a cheek cell, ask your teacher to inspect the picture to make sure that you in fact are looking at a cheek cell. If you need help, ask! vii. Use the lab worksheet to draw the cell and label its parts. 4. Turn in your work and clean up your station. 12 Cheek Cell Lab Worksheet Cheek Cell Lab Name:_________________________________________ Cell Type: Drawings: Low magnification: High Magnification / cell parts: Teacher Signature:___________________________________ Date:______ 13 Teacher Notes Cheek Cell Lab Objective: Observe cheek cells under a microscope. Level: 9-12 Subjects: Life science, Biology Prep Time: 10-20 minutes Duration: 30-40 minutes Materials Tooth picks or cotton swabs Microscope Glass slides and covers Iodine or Methylene Blue Eye droppers Paper towels Forceps Student worksheets Extensions: Can use onion or blood cells as well. Pre-lesson instructions: Have students work in groups of at least two for this lesson. Each group will need a microscope and materials to create a slide of cheek cells. Set up microscopes in a laboratory setting. Create a mixture of Methylene Blue in droppers ahead of time and label. (Warn students about the effects of stain.) Note that this lesson is an extension of the previous lessons on the cell and its parts. Model the entire procedure after all the students have their worksheets and are in groups. Ask if there are any questions. I sometimes find it necessary to stop the lab and discuss a teachable moment or a problem with the process if all the groups are having difficulty. Discussion / Wrap up: Have the students share their diagrams with the class. Discuss the diagrams as a class. Were the students surprised by what they saw? Why was the stain important? What difference did the power setting make in seeing their cells? 14