lecture 7

Question 1

describe antigens

Answer 1

○ Anything that stimulates a immune response
Proteins, lipids, polysaccharides, nucleic acid

Question 2

describe antibodies

Answer 2

○ Y-shaped protein
○ Made by B-lymphocytes in response to antigens
○ Binds to antigens
Monomers- IgG, dimer- IgA, pentamers-IgM

Question 3

describe agglutination

Answer 3

Antibody cross-links cells (e.g. Bacteria), forming a ‘clump’

Question 4

describe the ABO system

Answer 4

• Many antigens found on RBC membranes
  
  • Rh is present in 85% of humans, gives a + or -
  • Rh can cause erythroblastosis fetalis, a haemolytic disease of newborns
  • Blood type can be type A (has antigen A, and anti-B antibodies), type B (has antigen B, and anti-A antibodies), type AB (both A and B antigen, but NEITHER antibodies), or type O (has neither A or B antigens, but has both anti-A and anti B antibodies)
    People develop antibodies to RBC antigens they do NOT have

Question 5

describe blood typing

Answer 5

• A drop of blood mixed with antiserum (antibodies) that will agglutinate if has antigens that reacts to it
  
  • If blood fusion incorrect, causes cell clumping (agglutination) + haemolysis
  • E.g. If have a blood sample, add anti-A and Anti-B serum, and anti-A clumped, means has A-antigens, so is blood type A
  • CLUMPING = BLOOD TYPE
  • If NO clumping = O
  • Blood type O = universal DONOR (O-, O+ can only donate if Rh pos.)
  • Blood type AB = universal RECIPIENT (AB+, AB- can only do Rh-)
  • NOTE: type A or type B can donate to type AB, but AB can ONLY donate to AB
    Most common blood type is O+