Communicable Disease, Prevention And Immunity - Antibodies And Immune Response

Question 1

What are antibodies also called

Answer 1

Immunoglobulins

Question 2

What are antibodies composed of

Answer 2

Glycoproteins

Question 3

Describe the structure of antibodies

Answer 3

• Y shaped
• consist of 4 polypeptide chains (2 heavy, 2 light)
• variable region that can bind to a specific antigen

Question 4

Describe the variable region

Answer 4

• amino acid variations give the different shapes
• each antibody has a different variable region, with a complementary shape to bind to a specific antigen

Question 5

Describe the constant region

Answer 5

• amino acid sequences are the same
• phagocytes have specific complementary receptors to this region

Question 6

Describe the hinge region

Answer 6

allows flexibility in binding to more than one antigen

Question 7

Describe disulfide bridges

Answer 7

hold polypeptides together

Question 8

What are the four modes of action of antibodies

Answer 8

• opsonisation
• agglutination
• anti toxins
• neutralisation

Question 9

Describe opsonisation

Answer 9

• opsonins are a group of antibodies that bind to the antigen on a pathogen, marking it for destruction
• constant region acts as a binding site for phagocytes, which engulf pathogen

Question 10

Describe agglutination

Answer 10

• large antibodies bind pathogens together
• makes bacteria easier to engulf and prevents viruses entering host cells

Question 11

Describe antitoxins

Answer 11

Antibodies bind to toxins produced by pathogens, making them harmless

Question 12

Describe neutralisation

Answer 12

Antibodies binding to the surface of pathogens can prevent it binding to host cells

Question 13

What is the primary immune response

Answer 13

The first time the body is exposed to a pathogen

Question 14

What are the features of the primary immune response

Answer 14

• antigen presentation, clonal selection, clonal expansion and differentiation take several days
• pathogen multiplies and person gets ill
• antibodies are slowly produced
• memory cells remain in bloodstream

Question 15

What is the secondary immune response

Answer 15

Same pathogen invades the body again

Question 16

What are the features of the secondary immune response

Answer 16

• memory cells allow faster clonal selection, clonal expansion and differentiation
• antibodies are produced quicker and in larger numbers
• pathogen may be destroyed before any symptoms

Question 17

define the immune response

Answer 17

specific response to antigens on a pathogen, involving lymphocytes and antibodies