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Distinguish between an antigen and an antibody.
Distinguish between an antigen and an antibody.
An antigen is a molecule that stimulates an immune response whereas an antibody is a protein made in response to an antigen.
What is immunity?
What is immunity?
The ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitized white blood cells.
Differentiate between agglutination, opsonization, and neutralization.
Differentiate between agglutination, opsonization, and neutralization.
Agglutination enhances phagocytosis and reduces the number of infectious units, opsonization coats the antigen with antibody to enhance phagocytosis, and neutralization blocks the adhesion of bacteria and viruses.
What are the four main types of T cells?
What are the four main types of T cells?
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Explain why the immune system does not react to the body's own cells.
Explain why the immune system does not react to the body's own cells.
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What is the function of MHC molecules?
What is the function of MHC molecules?
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Distinguish between plasma and memory B cells.
Distinguish between plasma and memory B cells.
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Explain the Clonal Selection theory and its application to B cells.
Explain the Clonal Selection theory and its application to B cells.
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Describe how a T cell is activated by a macrophage that has encountered a bacterial cell.
Describe how a T cell is activated by a macrophage that has encountered a bacterial cell.
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Illustrate the primary and secondary immune response of IgG to a vaccine.
Illustrate the primary and secondary immune response of IgG to a vaccine.
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Distinguish between antibody-mediated immunity and cell-mediated immunity.
Distinguish between antibody-mediated immunity and cell-mediated immunity.
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Study Notes
Antigens and Antibodies
- Antigens stimulate an immune response; antibodies are proteins produced in response to antigens.
- Antibodies can recognize and bind to specific antigens.
Immunity
- Immunity is the ability to resist infections or toxins through specific antibodies or sensitized white blood cells.
Agglutination, Opsonization, and Neutralization
- Agglutination: Enhances phagocytosis by clumping pathogens, reducing the number of infectious units.
- Opsonization: Coats antigens with antibodies to promote phagocytosis.
- Neutralization: Blocks bacteria and viruses from adhering to cells and inhibits toxins.
Types of T Cells
- Helper T cells
- Cytotoxic T cells
- Memory T cells
- Suppressor T cells
Self-Tolerance in the Immune System
- The immune system does not attack the body’s own cells because it recognizes self-antigens versus foreign antigens.
- This prevents the body from launching an attack against its own cells.
Major Histocompatibility Complex (MHC)
- MHC molecules bind peptide fragments from pathogens and display them on cell surfaces for T-cell recognition.
- They are crucial for mediating interactions between pathogens and leukocytes, essential to the acquired immune response.
Plasma B Cells vs. Memory B Cells
- Plasma cells are derived from B cells and produce the first wave of antibodies against infections.
- Memory B cells retain information about the infection for a quicker response in future encounters.
Clonal Selection Theory and B Cells
- Clonal Selection Theory explains the rapid response of the immune system upon re-exposure to pathogens.
- B cells can clone themselves into plasma cells and memory B cells, with memory B cells remaining for faster responses in future infections.
T Cell Activation by Macrophages
- T cell activation needs an antigen-presenting cell like a macrophage displaying the antigen on MHC proteins.
- Helper T cells bind to the right antigen, leading to their activation, while memory T cells ensure a rapid response to future exposures.
Primary and Secondary Immune Response of IgG
- IgG provides protection against pathogens and toxins, first produced upon initial exposure.
- The primary response shows a lag phase as B cells differentiate; the secondary response is quicker due to existing memory B cells, resulting in higher levels and longer duration of antibodies.
Antibody-Mediated vs. Cell-Mediated Immunity
- Antibody-mediated (Humoral) immunity involves B cells binding to antigens, assisted by helper T cells, leading to plasma cell differentiation and antibody production.
- Cell-mediated immunity is triggered when a pathogen invades body cells, leading to direct attacks from T cells.
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Description
Test your knowledge of key microbiology concepts with these flashcards. This quiz covers essential terms such as antigens, antibodies, and immunity, helping you reinforce your understanding in preparation for exams.
