B1 Adaptive immunity

Question 1

What are antibodies?

Answer 1

Proteins that are produced by the immune system in response to a foreign substances like a virus or bacteria

Question 2

What are antibodies made up of?

Answer 2

4 polypeptide chains held together by disulphide bridges, antigen binding sites, the constant region, the variable region and light polypeptide chain

Question 3

What is the adaptive immune response?

Answer 3

When the immune system is activated, and antibodies are produced.

Question 4

What are examples of APC?

Answer 4

Infected body cell, a macrophages and cancer cells

Question 5

Describe the cell mediated reponse

Answer 5

1) After phagocytosis, antigens are presented on the cell surface (APC)
3) T helper cells have receptors that attach to antigens on APC (clonal selection)
3) This activates T helper cells and causes them to divide by mitosis and make clones (clonal expansion)
4) Cloned T helper cells differentiate into different cells. Some remain as T helper cells, some stimulate macrophages and some become T memory cells or T killer.

Question 6

What is the role of T helper cells?

Answer 6

Activating phagocytes and B cells

Question 7

What is the role of T killer (cytotoxic)?

Answer 7

They destroy abnormal, foreign and infected cells

Question 8

What is the role of T memory cells?

Answer 8

They provide long term immunity

Question 9

What is the cell mediated response?

Answer 9

The response of T cells to a foreign antigen. They only respond to antigens on the surface of cells.

Question 10

What is the Humoral response?

Answer 10

The activation and production of specific B cells to produce antibodies for specific non-self antigens. It can only take place after the cell mediated response.

Question 11

What are lymphocytes and where are they made?

Answer 11

White blood cells involved in the specific immune response. They are made in the bone marrow.

Question 12

Describe the Humoral response?

Answer 12

1) T helper cells for a specific antigen will bind to and activate a B cells
2/3) The activated B cell divide by mitosis to make more B cells
4) The B cells divide by mitosis to make more copies of B cells
5) Some B memory cells. These remain in the body as an active response to pathogens if there is future infection, providing long term immunity
6) Some become B plasma cells which produce antibodies

Question 13

Describe the Humoral response?

Answer 13

1) T helper cells for a specific antigen will bind to and activate a B cells
2/3) The activated B cell divide by mitosis to make more B cells
4) The B cells divide by mitosis to make more copies of B cells
5) Some B memory cells. These remain in the body as an active response to pathogens if there is future infection, providing long term immunity
6) Some become B plasma cells which produce antibodies

Question 14

What is the primary immune response?

Answer 14

The initial response caused by a first infection

Question 15

What happens during the primary response?

Answer 15

Antibodies specific to the pathogen’s antigens are produced. This process takes longer and the body needs to begin to make these antibodies.

Question 16

What is the secondary immune response?

Answer 16

A stronger and more rapid response caused by a second infection to the same pathogen. This process is quicker as clonal selection and clonal expansion are skipped due to B memory cells already being in the body.

Question 17

What can antibodies act as?

Answer 17

Opsonins, agglutinins and anti-toxins

Question 18

What happens when an antibody does agglutination?

Answer 18

Antibodies bind to antigens on pathogens forming an antigen antibody complex. This causes them to clump together and target them for destruction. Phagocytosis follows and phagocytes can recognise and destroy the pathogen in a large group .

Question 19

What happens when antibodies act as anti-toxins?

Answer 19

They bind to the toxins produced by pathogens, neutralising their harmful effects.

Question 20

What happens when antibodies act as opsonins?

Answer 20

Antibodies bind to dangerous antigen so that they can be easily recognised by antibodies or complementary receptors on phagocytic cells. This neutralises the pathogen and stimulates phagocytosis.

Question 21

What is passive immunity?

Answer 21

Antibodies are made by another organism not by yourself.