Immune response

• What do T lymphocytes (T cells) have on their surface?

  Receptors complementary to one specific antigen
• How do T lymphocytes (T cells) respond to an antigen?

  They bind to antigens and stimulate division
• What types of T cells do T lymphocytes differentiate into?

  Cytotoxic T cells, helper T cells, memory T cells
• What is the function of cytotoxic T cells?

  They kill infected cells
• What do helper T cells do?

  They release molecules that stimulate immune cells
• What do memory T cells do?

  They remain in the blood for future immunity
• What do B lymphocytes (B cells) have on their surface?

  Antibodies complementary to one specific antigen
• How do B lymphocytes respond to an antigen?

  They bind to the antigen and stimulate division
• What do B lymphocytes differentiate into after responding to an antigen?

  Plasma cells and memory B cells
• What do plasma cells do?

  They produce and release monoclonal antibodies
• What do memory B cells do?

  They remain in the blood for future immunity
• What are monoclonal antibodies?

  Antibodies produced by identical B cells
• Why do monoclonal antibodies have the same tertiary structure?

  They are clones of a single parent cell
• What is the role of the variable region of an antibody?

  It binds specifically to a complementary antigen
• What forms an antigen-antibody complex?

  The binding of the variable region to an antigen
• Why is the tertiary structure of the variable region crucial?

  It determines the binding ability to antigens
• What holds the polypeptide chains of an antibody together?

  Disulfide bridges between the polypeptide chains
• What is the quaternary structure of an antibody?

  The arrangement of four polypeptide chains
• How does agglutination occur with antibodies?

  Antibodies bind to antigens on pathogens
• What happens during agglutination?

  Clumping of pathogens occurs
• What is the result of pathogen agglutination?

  It makes it easier for phagocytes to destroy them
• How do antibodies help with toxins?

  They bind to toxins, inactivating them
• How can monoclonal antibodies be used in drug targeting?

  By delivering drugs to specific cells
• What is the benefit of attaching drugs to monoclonal antibodies?

  It targets specific antigens on cells
• How do antibodies block specific antigens on cells?

  By binding to antigens on the cell surface
• What is the effect of antibodies blocking antigens on cells?

  It prevents pathogens from entering cells
• What causes antigenic variability in pathogens?

  Mutations change the antigens on pathogens
• How does antigenic variability affect the immune response?

  • First infection: immune system produces specific antibodies
  • If antigen changes, memory B cells' antibodies may not match
  • Reduced immunity in subsequent infections