B5 The Immune System

Question 1

Each cell has _ _ that allow the immune system to identify other things

Answer 1

Specific molecules

Question 2

Specific molecules on cells allow them to recognise

Answer 2

Pathogens
Cells from other humans
Abnormal body cells
Toxins

Question 3

What is an antigen

Answer 3

A molecule that is found on the surface of cells and triggers an immune response

Question 4

What is a pathogen

Answer 4

A microorganism that causes disease

Question 5

What is antigen variability

Answer 5

Antigens on a pathogens surface changing structure due to mutation

Question 6

The effect of antigen variability on disease

Answer 6

Immune system no longer recognises antigen so memory b cells and vaccines aren’t effective

Question 7

The effect of antigen variability on disease prevention

Answer 7

Vaccines need to be regularly developed
Harder to achieve herd Immunity.

Question 8

Phagocytosis is a _ response

Answer 8

Non specific immune response

Question 9

What is the first 2 steps of phagocytosis

Answer 9

Phagocytes are attracted to chemicals released by a pathogen and move along a conc gradient
Phagocytes receptors bond to complementary antigens on pathogens surface

Question 10

Phagocytes are attracted to chemicals released by a pathogen and move along a conc gradient
Phagocytes receptors bond to complementary antigens on pathogens surface

What occurs in step 3 & 4 of phagocytosis

Answer 10

Phagocyte engulfs pathogen to form a phagosome.
Lysosomes fuse with phagosome

Question 11

Phagocyte engulfs antigen to form a phagosome.
Lysosomes fuse with phagosome

What is step 5 & 6 of Phagocytosis

Answer 11

Lysosomes release lysozymes which hydrolyse pathogen
The cytoplasm absorbs soluble products and expels the rest.

Question 12

Where do T Cells mature

Answer 12

In the thymus

Question 13

Where do B cells mature

Answer 13

In the Bone marrow

Question 14

Step one of the Cell Mediated Response (T Cells

Answer 14

Naive T Helper cells bind to antigen presenting cells

Question 15

Naive T Helper cells bind to antigen presenting cells

What is step 2 and 3 of the Cell Mediated Response

Answer 15

T Helper cells stimulated to clone
Clone T Helper cells stimulated B cells, Cytotoxic cells and phagocytosis

Question 16

What do Cytotoxic Cells do

Answer 16

Bind to an antigen presented on virus infected cells and release perforin, causing holes in the membrane and leading to cell death

Question 17

Step 1 of the humoral response

Answer 17

Naive B cells bind to complementary antigens

Question 18

Naive B cells bind to complementary antigens

What is step 2 and 3 of the humoral response

Answer 18

Antigen is presented on B cell’s surface

Antigen binds to complementary T helper cell receptor

Question 19

Antigen is presented on B cell’s surface

Antigen binds to complementary T helper cell receptor

What is step 4 & 5 of the humoral response

Answer 19

T Helper cell stimulates B cells to clone itself. Differentiate into plasma or memory B cell.

Question 20

What do plasma cells do

Answer 20

Release antibodies

Question 21

What is an antibody

Answer 21

A protein produced by B cells in response to the presence of a specific antigen

Question 22

How long do plasma cells last for

Answer 22

A few days

Question 23

What do memory B cells do

Answer 23

When a specific pathogen is encountered, they clone themselves into Plasma or memory B cells

Question 24

How long do memory B cells last

Answer 24

For years

Question 25

What is agglutination

Answer 25

Antibodies clumping which promotes phagocytosis

Question 26

What are monoclonal antibodies

Answer 26

Antibodies with the same tertiary structure produced from cloned B cells

Question 27

What is passive immunity

Answer 27

Antibodies are Introduced into the body and provide short term immunity

Question 28

What is active immunity

Answer 28

Body produces its own antibodies after exposure and provides long term immunity

Question 29

What is herd immunity

Answer 29

Where most of the population is vaccinated and therefore those who aren't vaccinated have a decreased chance of coming into contact with the disease

Question 30

The 4 structures related to the outer layer of a HIV Virus

Answer 30

Matrix Capsid Lipid envelope Attachment protein

Question 31

The 2 structures related to the inner parts of a HIV Virus

Answer 31

Reverse transcriptase RNA

Question 32

Step 1 of HIV Replication in Helper T Cells

Answer 32

Attachment protein binds to Helper T Cell

Question 33

Step 1: Attachment protein binds to Helper T Cell What is step 2?

Answer 33

Step 2: Reverse Transcriptase and RNA Enter the cell

Question 34

Step 1: Attachment protein binds to Helper T Cell Step 2: Reverse Transcriptase and RNA Enter the cell What is step 3?

Answer 34

Step 3: Reverse transcriptase converts RNA to DNA

Question 35

Step 1: Attachment protein binds to Helper T Cell Step 2: Reverse Transcriptase and RNA Enter the cell Step 3: Reverse transcriptase converts DNA to RNA What is step 4?

Answer 35

Step 4: Viral DNA is integrated into host DNA

Question 36

Step 1: Attachment protein binds to Helper T Cell Step 2: Reverse Transcriptase and RNA Enter the cell Step 3: Reverse transcriptase converts DNA to RNA Step 4: Viral DNA is integrated into host DNA What is step 5 & 6?

Answer 36

Step 5: Viral mRNA & proteins produced Step 6: HIV Is assembled and leaves the cell

Question 37

What is the ELISA test

Answer 37

Test for antigens of specific diseases

Question 38

Uses of antibodies in the Elisa test

Answer 38

Complementary Antibodies bind to the antigen A second antibody with an enzyme attached will bind to the antigen.

Question 40

Use of mAbs in targeting medication

Answer 40

MAbs bind to complementary antigens and has a drug attached which kills the cancer cell.

Question 41

Use of mAbs in diagnosis

Answer 41

Many conditions produce molecules that bind to mAbs Formation of antigen antibody complexes enables the condition to be detected

Question 42

Ethical considerations for mAbs

Answer 42

Death and dangerous side effects in human trials Infecting mice