2C-cells and immune system

Question 1

what are antigens

Answer 1

molecules that can generate an immune response when detected by the body

Question 2

why are drugs given to a person who just had an organ transplant

Answer 2

because the cells will have some antigens that are different to the persons’ so the foreign antigens trigger an immune response leading to the rejection of the organ so drugs are taken to supress the recipients immune response

Question 3

what is a phagocyte

Answer 3

a white blood cell

Question 4

what is phagocytosis

Answer 4

engulfment of pathogens

Question 5

what are the steps in phagocytosis

Answer 5

the phagocyte recognises the foreign antigens on a pathogen making the cytoplasm of the phagocyte move around the pathogen engulfing it, the pathogen is now contained in a phagocytic vacuole. then the lysosome fuses with the phagocytic vacuole and the lysozyme breaks down the pathogen.
The phagocyte presents the pathogen’s antigens by sticking the antigens on its surface to activate other immune system cells. its acting as an antigen presenting cell.

Question 6

what is a T-cell

Answer 6

another type of white blood cell it has receptor proteins on its surface to bind to complementary antigens presented to it by phagocyte

Question 7

what is a helper T-cell

Answer 7

release chemicals that activates and stimulates phagocytes and cytotoxic T-cells which kill abnormal and foreign cells. they also active B-cells

Question 8

what are B-cells

Answer 8

a white blood cell covered with antibodies forming an antigen-antibody complex. B-cells have a different shaped antibody on its membrane so different one bind to different antigens

Question 9

what is clonal selection and how do B-cells divide into plasma cells

Answer 9

when an antibody on the surface of a B-cell meets a complementary shaped antigen this is called clonal selection. this together with the substances released for T-cells activates B-cells. the activated B-cell divides into plasma cells

Question 10

what are monoclonal antibodies

Answer 10

plasma cells and B-cells are identical so secrete antibodies specific to the anitgen

Question 11

what is agglutination

Answer 11

antibody has two binding sites so binds to two pathogens at the same time so they become clumped together

Question 12

What does the specificity of an antibody depend on

Answer 12

the variable regions which for the antigen binding sites

Question 13

what do all antibodies have in common

Answer 13

they have the same constant regions

Question 14

what is the antigen-antibody complex structure

Answer 14

refer to pg 118

Question 15

what are the two immune responses

Answer 15

cellular and humoral response

Question 16

what is the cellular response

Answer 16

the T-cells and the other immune system cells that they interact with

Question 17

what is the humoral response

Answer 17

B-cells, clonal selection and production of the monoclonal antibodies

Question 18

what is the primary response

Answer 18

when an antigen enters the body for the first time and activates the immune system.

Question 19

why is primary response slow

Answer 19

because there aren’t many B-cells making the the antibodies needed to bind to it. meanwhile infected person shows symptoms.

Question 20

How are memory cells produced

Answer 20

after being exposed to the antigen, T-cells and B-cells produce memory cells. Memory T-cells remember the antigen second time round and memory B-cell record the specific antibodies needed to bind to the antigen.

Question 21

what is the secondary response

Answer 21

if smae pathogen enters the body the immune system produces a quicker, faster response