dieases

• ringworm is caused by fungi
• direct transmission:

  • direct contact
  • airborne droplets
• black sigatoka is caused by fungi
• chemical defense mechanism in plants = insect repellents
• macrophages can become antigen presenting cells, which present antigens to T cells
• what are expulsive reflexes?

  Reflexes that expel substances from the body.
• non specific defences are faster than specific defenses
• opsonins make it easier for phagocytes to identify pathogens
• what can the immune system identify:

  • pathogens
  • toxins
  • abnormal body cells
• functions of cloned T cells:

  • develop into memory cells
  • develop into t killer cells
  • stimulate phagocytosis
• purpose of hinge region = allow antibody flexibility so it can bind to multiple antibodies at once
• antibodies have unique binding sites in their variable regions that are complementary to specific antigens 
• T helper cells bind to antigen presenting cells
• why are antibiotics ineffective on viruses:

  viruses lack cell structures for antibiotics to act on

  antibiotics cannot reach viruses as they're found within host cells
• Antibiotics effect on bacteria:

  they might prevent the synthesis of bacterial cell walls

  they might disrupt protein activity in the cell membrane

  they might disrupt enzyme action

  they might prevent DNA synthesis 

  they might prevent protein synthesis 
• passive immunity = given antibodies made by a different organism
• reducing antibiotic resistance = choosing appropriate antibiotics for treatments when needed
• disulfide bridges join polypeptide chains together
• antibodies bind to specific antigens:

  antibodies have a variable region that has a specific amino acid sequence 

   tertiary structure of the binding site is complementary to specific antigens

  forms an antigen-antibody complex