Term
| What are the adaptive immunity's defense mechanisms? |
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Definition
| Humoral response and cell-mediated response |
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Term
| What is the humoral response of adaptive immunity? What is the cell-mediated response for adaptive immunity? |
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Definition
Humoral response is when antibodies secreted by B cells fight against infection in body fluid (blood, lymph) in three different ways, neutralization, opsonization, and active complement.
Cell-mediated response is when cytotoxic t cells fight infection in body cells |
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Term
| What is adaptive immunity? |
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Definition
| Slow responding molecular recognition of specific traits to specific pathogens using any receptors, which is activated after innate immune response. Occurs in vertebrates only |
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Term
| What are the innate immunity's defense mechanisms? |
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Definition
| Barrier defenses and internal defenses |
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Term
| What are the barrier defenses in innate immunity? |
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Definition
| Skin, mucous membranes, secretions |
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Term
| What are the internal defenses in innate immunity? |
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Definition
| Phagocytic cells, natural killer cells, antimicrobial proteins, inflammatory response |
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Term
| Describe the roles of helper T cell in both humoral and cell-mediated immunity. |
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Definition
Helper T cells triggers both immune responses. By sending signals from secreting cytokines
In humoral immunity, helper T cells proliferate and check to see if B cells have a match with the pathogen, then gives the B cells permission to activate and allow them to secrete antibodies by plasma cells and memory cells.
In cell-mediated immunity, helper T cells check to see if cytotoxic T cells are perfectly matched to a pathogen and then allows them to activate and attack on infected cells with their effector T cells |
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Term
| Describe the role of an antigen-presenting cell in helper T cells function (both humoral and cell-mediated immune responses) |
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Definition
1) Antigen-presenting cell eats pathogen degrading it and displaying it's fragments with class II MHC molecules. Helper T cell binds to MHC molecules by antigen receptor and accessory protein
2) Binding of helper T cell secretes cytokines by antigen-presenting cell. Cytokines activate helper T cell and stimulates proliferation
3) Proliferation produces clones of activated helper T cells all with receptors for the same antigen fragment complex with same specific antigen. They secrete other cytokines to help activated B cells and cytotoxic T cells |
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Term
| For T cells, distinguish between function of effector cells (cytotoxic T cells) and memory cells and when each are produced after exposure to antigen. |
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Definition
| After exposure to antigen, antigen receptor binds to epitope and begins proliferation (clone selection mitosis) The effector T cells are short-lived cells that effects antigen immediately and any pathogen producing that antigen. The antigen is exposed by a class I MHC molecule that does antigen presentation so that the correct cytotoxic cell can bind to it. Memory cells are long lived cells that elicit effector cells if the same antigen is encountered again. |
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Term
| Describe how cytotoxic T cells help combat an infection. |
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Definition
1) Perforin: Makes a pore in the body cells
2) Granzymes: Enzymes that start a chain reaction to make the cells undergo apoptosis
3) The third being apoptosis, programs the cell to kill itself |
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Term
| Describe three mechanisms of how antibodies function to combat infection. |
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Definition
1) Neutralization: Antibodies bind to surface protein on virus preventing virus's ability to bind to host cell
2) Opsonization: Binds antibodies to antigen on surface of bacteria promoting phagocytosis by macrophage and neutrophils
3) Activation of complement system and core formation: First the antibodies bind to antigens on surface of foreign cells, activating complement system
The membrane attack complex forms pores in foreign membrane allowing water and ions to rush in the foreign cell making it explode! (lyses) |
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Term
| For B cells, distinguish between the function of effector cells (plasma cells) and memory cells and when each are produced after exposure to antigen. |
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Definition
Plasma cells are effector cells of B cells that secrete antibodies.
Memory cells are the remaining cloned cells from proliferation that live long and elicit effector cells after encountering the same antigen again |
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Term
| Describe how plasma cells help combat an infection. |
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Definition
| Plasma cells help combat in an infection because they are effector forms of B cells that secrete antibodies that immediately take effect against an antigen and any pathogen secreting that specific antigen |
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Term
| How does the B cell activate in humoral response (with clonal selection)? |
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Definition
| Most protein antigens require helper T cell to trigger a humoral response, thus a macrophage or dendritic cell can activate a helper T cell which can activate a B cell to elicit to antibody-secreting plasma cells and memory cells from proliferation |
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Term
| Describe the role of clonal selection in the immune response. |
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Definition
| Clonal selection is the proliferation of B or T cells into clone cells in response to a specific antigen and immune cell signals. B and T cells both differ in clonal selection but they both encounter the antigen, picks which lymphocyte will divide to produce clonal population of thousands of cells specific for that epitope, and generate memory cells as well as effector cells. |
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Term
| Explain why the antigen receptors of lymphocytes are tested for self-reactivity during development, and what happens to cells that are self-reactive |
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Definition
The body contains some immature lymphocytes that produce specific receptors for the organism's own epitopes.
Antigen receptors of lymphocytes are tested for self-reactivity during development to distinguish self from non-self through apoptosis and inactivation leaving only receptors that can react to foreign molecules.
Example: B cells train in the bone marrow during the absence of pathogens. If the B cells attach themselves to self cells, it will go through apoptosis making it self-reactive |
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Term
| Explain the function of the MHC molecules, and their role in antigen presentation. |
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Definition
| MHC molecules (major histocompatibility complex) molecules are host proteins that show antigen fragments on cell surface. Their role in antigen presentation is to display the antigen fragment in an exposed part of the MHC protein |
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Term
| Describe the protein structure and function of an antibody/immunoglobulin, and where the variable (v) and constant (c) regions are found. |
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Definition
| Antibody/Immunoglobulin is a secreted protein from the B cell antigen receptor binding to an antigen. The variable regions are found at both tips of the heavy and light chains. The constant region is the bottom part of the heavy and light chains. The bottom of the heavy chain constant region has the transmembrane region which is anchored to the plasma membrane. It also has the cytoplasmic tails. Disulfide bridge holds the heavy and light chains together |
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Term
| Describe the antigen receptors on the surface of T lymphocytes (aka T cells) and the result when they bind to an antigen. |
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Definition
| T cells are types of lymphocytes that migrate from the bone marrow to the thymus and mature there. The T cell only has two different polypeptide chains (the alpha and beta). T cells only bind to fragments of antigens that are displayed on the surface of host cells through antigen presentation on the opening of an MHC protein. As a result, the T cell can attack infected cells. |
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Term
| Describe the antigen receptors on the surface of B lymphocytes (aka B cells) and the result when they bind to an antigen. |
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Definition
B cells are types of lymphocytes that remain in the bone marrow to mature and train there in order to be able to recognize self-molecules, which is not always fool proof. They patrol in the lymph nodes. They have 4 polypeptide chains (two light chains and two heavy chains). The B cell antigen receptor binds to an antigen leading to the secretion of antibodies. B cell antigen receptors are like toll-like receptors in innate immunity but their antibodies bind to undamaged antigens in the blood and lymph. Their antibodies can bind to antigens on the surface of pathogens or free in body fluids.
When the antigen receptor on the surface of the B cell is still attached, it is called the B cell antigen binding site. When the antigen receptor on the B cell is detached, it is called antibody/immunoglobulin |
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Term
| Define antigens, epitope, and antigens receptors. |
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Definition
Antigens: A substance that draws out B or T cell response
Epitope: Small part of antigen that connects to antigen receptors
Antigen receptors: Proteins in which B or T cell binds to an antigen protein initiating recognition in adaptive immunity |
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Term
| *Know how two types of cells found in your tissues that can trigger inflammation, the chemical messengers they release, and the results of sending these chemical messengers**. |
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Definition
Types of cells found in tissues that can trigger inflammation: connective tissue (where mast cells are found) and squamous epithelium (where plate like blood vessels are found)
Chemical Messengers released:
Histamine: Stored in densely packed vesicles of mast cells that are released at places where damage triggers blood vessels to dilate and become more permeable
Cytokines: Signaling molecules that mediate immune responses released by macrophages and neutrophils
Result: Inflammation. Histamine causes capillaries to dilate and leak fluid into neighboring tissues, which causes swelling. The cytokines released by macrophages and neutrophils promote blood flow to the place of injury/infection. The increase in blood supply makes the redness and increased skin temperature of an inflammatory response
Activated complement proteins promote more histamine attracting more phagocytic cells simultaneously increasing blood flow helps deliver antimicrobial peptides resulting to pus (white blood cells + dead pathogen + cell debris damage from tissue) |
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Term
| **The local inflammatory response in three steps.** |
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Definition
1) At the place of injury, mast cells in the connective tissue release histamine which causes the nearby capillaries to dilate. Macrophages release other signaling molecules that also increase blood flow
2) Capillaries dilate becoming more permeable allowing fluid with antimicrobial peptides to enter the tissue. Signals released by immune cells attract neutrophils.
3) Neutrophils eat pathogens and cell debris, then the tissue heals |
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Term
| Explain the difference between active and passive immunity, and know an example of passive immunity. |
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Definition
Active immunity: Defenses arise when pathogen infects the body and initiates primary or secondary response.
Passive immunity: Antibodies in the recipient (fetus) are produced by another individual (mother).
An example of passive immunity is IgG antibodies in the blood of a pregnant female goes from the placenta to the fetus |
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Term
| Describe an allergic reaction, including the roles of IgE, mast cells, and histamine. |
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Definition
Allergic Reactions: Exaggerated (hypersensitive) response to certain antigens called allergens
IgE are antibodies secreted by plasma cells that sometimes attack by their base to mast cells releasing histamine and other inflammatory chemicals, which can bring about allergy symptoms |
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Term
| Describe the infectious agent that causes AIDS and explain how it damages the immune system. |
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Definition
| Aids (Acquired immunodeficiency syndrome) is impairment of immune system (due to untreated HIV infection; which abolishes adaptive immune response) leaves body open to infections and cancers that a normal system would defeat. It damages the immune system by damaging the nerves and the body wasting. This happens because your helper T cells don't work anymore, they are destroyed, which means that helper T cells can no longer activate B cells and cytotoxic T cells. Other cells are also destroyed in the immune system. In AIDS, without the immune system of activation, viruses, bacteria, and fungi cannot be controlled |
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Term
| Describe the function of the immune system |
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Definition
Patrol and look for things that don't belong -- non-self
Recognize pathogen
Attack and clear pathogen
Communication with other cells and tissues |
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Term
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Definition
| In all animals, this immunity recognizes common traits shared among many pathogens using a small set of receptors and with fast response. |
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Term
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Definition
| An intracellular binding receptor located on inner surface of vesicles; binds to double stranded RNA that have qualities of certain infected agents |
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Term
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Definition
| An intracellular binding receptor that binds to CpG DNA |
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Term
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Definition
| An extracellular binding receptor located on the immune cell plasma membrane, which binds to LPS (lipopolysaccharide_ that is foreign carbohydrate to the body |
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Term
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Definition
| An extracellular binding receptor that binds to flagellin, the star protein of bacteria in flagella |
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Term
| Define phagocytosis and explain how phagocytes combat pathogens. |
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Definition
| Phagocytosis is a process that ingests and breaks down bacteria as well as other foreign substances. Phagocytes combat pathogens by ingesting them or secreting chemicals to kill them. There are the neutrophils, macrophages, dendritic cells, and natural killer cells |
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Term
| Define neutrophils, where they normally reside in the body, and their role in combating pathogens. |
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Definition
| Neutrophils are small phagocytes that circulate in the blood and are attracted by signals from infected tissues. They respond to that signal and then engulf and destroy the infecting pathogens |
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Term
| Define macrophages, where they normally reside in the body, and their role in combating pathogens. |
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Definition
| Macrophages are large phagocytes that sometimes migrate throughout the body or reside permanently in organs and tissues where they encounter pathogens the most. They entrap bacteria and eat them |
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Term
| Define dendritic cells, where they normally reside in the body, and their role in combating pathogens. |
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Definition
| Dendritic cells are mainly found in tissues, like the skin, that contact the environment by raising levels of awareness in adaptive immunity against pathogens they encounter and engulf. They provide additional functions in innate defense |
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Term
| Define natural killer cells, where they normally reside in the body, and their role in combating pathogens. |
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Definition
| Natural killer cells circulate throughout the body and detect an abnormal range of surface proteins with traits of some virus-infected and cancerous cells. These cells release chemicals that lead to cell death, preventing further spread of virus or cancer by recognizing infected cells as they patrol organs and kill the cell when they detect the infection |
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Term
| Explain how interferons combat pathogens, where they originate, and how they function to combat pathogens. |
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Definition
| Interferons are proteins that provide innate defense by interfering with viral infections. These proteins are released by infected cells and go to uninfected cells where they cause cells to go into an antiviral state where they cannot penetrate the cell. This is only activated during an infection. |
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Term
| In what organ do all leukocytes arise? |
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Definition
| Bone marrow, Thymus, Lymph nodes/vessels, Spleen |
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Term
| What is the function of the lymphatic system? |
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Definition
| The lymphatic system has tubes that drain interstitial fluid from your tissues, they have lymphatic vessels that lead to the lymph nodes, which trap pathogens, then the immune cells activate there to dig through the garbage and kill them |
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Term
| What are the chemical defenses in innate immunity? |
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Definition
Low pH- kills some pathogens...
For example: Stomach has 2-4 pH, skin and reproductive tract has 4-5pH
Lysozyme- enzyme that kills bacteria found in tears, saliva, and mucus |
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Term
| How do leukocytes know when a pathogen is present? |
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Definition
| Recognition... they have receptors called Toll-Like Receptors |
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Term
| What are Toll-Like Receptors |
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Definition
| Recognition immune cell proteins found in your membranes; they recognize molecules commonly found in pathogens |
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Term
| Describe the inflammatory response, including the four characteristics of inflammation (rubor, tumor, calor, dolor), how inflammation is triggered, and how it affects blood vessels of the infected tissue, the effect on neutrophils! |
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Definition
Tumor- Swelling
Rubor- Redness
Calor- Heat
Dolor- Pain
Inflammation recruits immune cells to infected tissues, destroy pathogens, heal tissue
It is triggered by defense of the body going down, for example a breach in the skin brings down barrier defense of body. Then cells like mast cells release histamine. neutrophils to come and engulf bacteria from the blood vessels which dilate from the histamine. Causes swelling and redness due to vasodilation and permeability. |
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Term
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Definition
| Immune cell, not a pathogen, that has toll-like receptors to send for help due to invading bacteria. It RELEASES HISTAMINE to cause blood vessels to dilate, which cause blood vessels to become permeable to get rid of infection where immune cells come out of the blood cells. |
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Term
| Describe the role of complement proteins in innate immunity, when and where they are present, where they are made, where they act, and what they combat. |
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Definition
| Complement proteins are a set of about 30 proteins that can bind and burst (lyse) pathogens. They are made in the liver at all times but they are found in the blood stream. The complement system patrols the blood stream and attack pathogens and cause them to burst. |
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Term
| What is one way that the humoral response in adaptive immunity is different from innate immunity |
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Definition
| The humoral response contains B cells that secrete antibodies/immunoglobulins. These are used to recognize and fight pathogens whereas innate immunity uses toll like receptors to fight pathogens |
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Term
| What are antibodies? How are antibodies specific to pathogens? How and when do B cells make antibodies? How and where do antibodies combat pathogens? |
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Definition
| Antibodies, which fight outside your cells, are types of free floating proteins secreted by B cells that combat pathogens when a specific bacteria is detected. Antibodies combat pathogens in three ways: neutralization, opsonization, and active complement |
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Term
| Explain the three ways antibodies combat pathogens. |
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Definition
| The first way antibodies combat pathogens is by neutralization. This is when antibodies bind to antigens of pathogens to prevent the pathogen from binding to other cells. The second way is by opsonization which is when a phagocyte binds to the antibody covered pathogen and promotes phagocytosis with macrophages and neutrophils. The pathogen looks appealing because it is surrounded by antibodies so the pathogen eats them (both the virus and the antibodies!) The last is active complement where the complement proteins are activated and have a high affinity to pathogens covered in antibodies, thus complement proteins are induced, recognize pathogens, pokes holes in it's membrane, and lyses it leaving the antibodies alone |
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Term
| Explain how the particular structure of a lymphocyte's antigen binding site forms during development using gene arrangement. |
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Definition
| In the B cells, each B cell has receptor diversity in it's antigen binding site due to gene arrangement, which cuts and pastes DNA randomly. This provides unique variable regions of protein in each B cell's antigen receptors |
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Term
| Explain how the particular structure of a lymphocyte's antigen binding site forms during development using gene arrangement. |
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Definition
| In the B cells, each B cell has receptor diversity in it's antigen binding site due to gene arrangement, which cuts and pastes DNA randomly. This provides unique variable regions of protein in each B cell's antigen receptors. B cell goes through apoptosis during training of B cells in the bone marrow in the absence of pathogens because the B cells sometimes go through gene arrangements that match your own cells, so they kill themselves |
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