12.6 The Specific Immune System

Question 1

Antigens

Answer 1

Molecules on all cell surfaces. Allows the body to recognise the cell as self or non-self

Question 2

Antibodies

Answer 2

Polypeptide involved in immune response

Question 3

Immunoglobulins

Answer 3

Glycoprotein that binds to specific antigens on pathogen that triggered immune response.

Question 4

Heavy chain

Answer 4

Section of the antibody that allows fir antigen-specific binding. Held together by disulfide bridges

Question 5

Light chain

Answer 5

Allows expression and secretion of functional antibodies. Increases variability of antibodies

Question 6

Antigen-antibody complex

Answer 6

When an antibody binds to an antigen

Question 7

Agglutinin

Answer 7

Specialised antibody that binds foreign cells together, forming a clump (like glue)

Question 8

T helper cell

Answer 8

Have receptors on cell-surface membrane, binding to surface antigens on APCs. Produce interleukins. These stimulate activity of B cells. Increases antibody production. Attracts macrophages

Question 9

Interleukin

Answer 9

Type of cytokines that are secreted in order to bind to the pathogen via a receptor molecule on the cell’s surface

Question 10

T killer cell

Answer 10

Destroys the pathogen carrying the antigen. Produces a chemical called perforin which kills the pathogen by creating perforations making it permeable

Question 11

T memory cells

Answer 11

Long lifespan, part of immunological memory. Able to divide rapidly in 2nd contact of a pathogen

Question 12

T regulator cells

Answer 12

Suppress the immune system. Stop immune response once pathogen is killed. Protects self antigens

Question 13

Plasma cells

Answer 13

Produce antibodies. Only live for a few days but produce around 2000 antibodies per second while active

Question 14

B effector cells

Answer 14

Divide to form plasma cell clones

Question 15

B memory cells

Answer 15

Programmed to remember specific antigens and enable the body to make rapid responses when encountered a 2nd time

Question 16

Antigen presenting cell (APC)

Answer 16

Cell breaking down pathogens and presents cellular fragments on their surface for detection by other immune cells

Question 17

Clonal selection

Answer 17

The point at which the B cell with the correct antibody to overcome a particular antigen is selected for cloning

Question 18

Clonal expansion

Answer 18

Activated B cell divided by mitosis to give clones of plasma cells and B memory cells.

Question 19

Primary immune response

Answer 19

Cloned plasma cells produce antibodies that fit antigens on surface of pathogen. Bind to antigens and disable them. Can also act as opsonins or agglutinins

Question 20

Secondary immune response

Answer 20

When plasma cell clones are produced in a secondary interaction with a pathogen due to the presence of B memory cells produced by some cloned B cells from the initial interaction

Question 21

Autoimmune disease

Answer 21

When the immune system stops recognising ‘self’ cells and starts to attack itself