Candy Antigens and Antibodies

Transcription

1 LAB ACTIVITY: Candy Antigens and Antibodies TEACHER S EDITION Curricular Links: Biology 20, Science 30 Class Time: 1 period Suggested Answers: Question 1: What is the main function of red blood cells? The main function of red blood cells is to deliver oxygen from the lungs to all of the cells of the body. Question 2: Identify two reasons for the round, biconcave shape of red blood cells. The round shape allows red blood cells to smoothly pass through narrow capillaries. The biconcave shape increases the surface area to facilitate gas exchange, without compromising the round shape. Question 3: Define the term antigen. An antigen is any substance that stimulates the immune system to produce antibodies. Question 4: Explain how A, B, AB and O blood cells differ from each other. They differ only in the final carbohydrate unit that is added to long carbohydrate chain. For A and B the final unit is different. For O, the unit is missing altogether. Question 5: explain why a large amount of blood cells undergoing agglutination could lead to a patient s death. The clumps that form would block off small blood vessels, such as capillaries. This would prevent the delivery of oxygen and the removal of wastes. Without oxygen, tissue death will begin to occur, and organs such as the heart and brain will stop working, leading to death. Question 6: Explain why the O antigen is present on all blood cells. The O antigen is present because is a precursor to the A and B antigens. Question 7: Explain why the term O antigen is technically incorrect. The term O antigen is technically incorrect because it does not stimulate the immune system to produce antibodies. All individuals have the O antigen, so it is not recognized as foreign. Question 8: Explain the importance of a mechanism in your body to identify, immobilize and destroy foreign cells. Without this mechanism, bacteria, virus, fungi and other parasites would be able to rapidly divide in the body, feeding on its tissues. The importance of the immune system is apparent when you think about how quickly decomposition occurs when an organism dies. The immune system is no longer fighting off invaders and the body is quickly consumed. AICCSLabActivityCandyBloodCellsTR Alberta Ingenuity Centre for Carbohydrate Science 1/7

2 Drawing of antigens bound by an antibody: (Answers will vary) CHECK YOUR UNDERSTANDING 9) In this activity which item(s) is(are) used to represent the following: a) Blood cells Marshmallows b) A antigens Sour patch kids heads cut to leave a flat edge c) B antigens Sour patch kid s heads cut to leave a V-shaped edge d) O antigens Toothpicks e) Antibody Sour soother with sour patch kids bodies attached AICCSLabActivityCandyBloodCellsTR Alberta Ingenuity Centre for Carbohydrate Science 2/7

3 10) Copy the statements below into your notebook and then fill in the blanks. Answers will vary. All possibilities are given. In this activity I was blood type A and I received some type B blood from another person. My immune system recognized B antigens on the surface of the other In this activity I was blood type A and I received some type AB blood from another person. My immune system recognized B antigens on the surface of the other In this activity I was blood type A and I received some type O blood from In this activity I was blood type B and I received some type A blood from another person. My immune system recognized A antigens on the surface of the other In this activity I was blood type B and I received some type AB blood from another person. My immune system recognized A antigens on the surface of the other In this activity I was blood type B and I received some type O blood from In this activity I was blood type AB and I received some type A blood from AICCSLabActivityCandyBloodCellsTR Alberta Ingenuity Centre for Carbohydrate Science 3/7

4 In this activity I was blood type AB and I received some type B blood from In this activity I was blood type AB and I received some type O blood from In this activity I was blood type O and I received some type A blood from another person. My immune system recognized A antigens on the surface of the other In this activity I was blood type O and I received some type B blood from another person. My immune system recognized B antigens on the surface of the other In this activity I was blood type O and I received some type AB blood from another person. My immune system recognized A and B antigens on the surface of the other 11) Explain why individuals with type AB blood do not produce antibodies against any of the A, B, or O antigens. Individuals with AB blood type have all three antigens (A, B, and O), so they do not recognize them as foreign. AICCSLabActivityCandyBloodCellsTR Alberta Ingenuity Centre for Carbohydrate Science 4/7

5 12) Based on the idea that antibodies will be produced to bind to foreign antigens, complete the table below in your notebook. Blood Type Antigens Present Blood types that would cause an immune response Blood types that would not cause an immune response A A, O B, AB A, O B B, O A, AB B, O AB A, B, O None A, B, AB, O O O A, B, AB, O None 13) Copy the statements below into your notebook and then fill in the blanks. People with blood type O are considered to be universal donors because their blood has no A, B or O antigens that are recognized as foreign by the recipient s immune system. People with blood type AB are considered to be universal recipients because their immune systems do not recognize any of the A, B or O antigens as foreign. 14) In this activity, candy heads are used to represent the unique regions of the A and B antigens. Explain why this is an appropriate analogy. Humans recognize faces based on shape. White blood cells in the immune system recognize antigens based on shape. 15) In this activity, binding could occur because surfaces were sticky. Construct a possible explanation of the forces of attraction that causes the stickiness on a molecular level. Use this idea to explain how more than just the shapes of an antigen and antibody is important for effective binding. Stickiness is caused by intermolecular forces (forces between molecules). Positive charges in one molecule are attracted to negative charges in another molecule. When binding, the position of the charges are very important, because the closer they are, the stronger the attractive force. AICCSLabActivityCandyBloodCellsTR Alberta Ingenuity Centre for Carbohydrate Science 5/7

6 16) The immune response involves several types of white blood cells. These include: B cells Helper T cells Killer T cells Macrophages Memory T cells Suppressor T cells Based on the clues given in the names of the cells and information in this activity and in your textbook, match each term with its best description. Descriptions a) Carbohydrate structure that extend out from a cell that may be recognized as foreign to the body, and therefore, stimulate an immune response. Antigens b) A white blood cell that patrols the circulatory system looking for foreign antigens. When it identifies a foreign antigen, it engulfs the cell and displays the antigen. Macrophage Terms Antibodies Antigens B cell Helper T cell Killer T cell Macrophage Memory T cell Suppressor T cell c) Receives information from macrophages and relays the information to B cells Helper T cell d) Using information it receives from helper T cells, this cell type produces antibodies to bind specifically to the original foreign antigen. B cells e) Using information from helper T cells, this cell type seeks out and destroys cells displaying a specific foreign antigen. Killer T cell f) This type of cell uses information from helper T cells to keep a record of the specific foreign antigen in case of a future attack by the same bacteria or virus. Memory T cell g) These Y-shaped protein molecules bind to specific antigens on the surfaces of foreign cells. Antibodies h) This cell type releases hormones to shut down the immune response once the infection is threat has been dealt with. AICCSLabActivityCandyBloodCellsTR Alberta Ingenuity Centre for Carbohydrate Science 6/7

7 Suppressor T cell 17) Vaccines can be effective in preventing infections of bacteria and viruses. Often, the active ingredient in each vaccine is often all or part of an antigen from a specific bacterium or virus. Vaccines are usually administered with an injection. a) In this lab activity, which candy(s) would likely serve as an effective vaccine against blood type A, if we consider blood type A cells to be an infectious agent. Sour patch kids cut to have flat edge b) Based on your knowledge of how the immune system functions, explain why vaccines are effective. The vaccine is recognized as a foreign invader and an immune response occurs. The vaccine is dealt with easily, because it is not actually infectious. When the immune response is finished, a record is kept of the antigen, so that the immune response will be much quicker when the actual virus or bacterium enters the body. c) Explain why a vaccination for the bacterium that causes tuberculosis would not be effective against the virus that causes influenza. The bacterium and the virus have different antigens, so vaccines for them will be specific to that particular strain of the bacterium or the virus. 18) When patients receive organ transplants, they are given drugs to suppress the activity of their immune system. Explain why this is necessary. Because the organs received may contain antigens that the immune system of the patient will recognize as foreign. The immune system will then mount an attack against the transplanted organ. When the transplanted organ is attacked by the patient s immune system it is called rejection. AICCSLabActivityCandyBloodCellsTR Alberta Ingenuity Centre for Carbohydrate Science 7/7