Exam 4

Question 1

Cytotoxic T cells express what?

Answer 1

CD8 to recognize MHC 1 proteins on infected cell

Question 2

How do cytotoxic T cells act?

Answer 2

they kill antigen-bearing target cells direclty

Question 3

What do T-helper cells express?

Answer 3

CD4 to recognize MHC 2 protein on infected cell

Question 4

How do T-helper cells act?

Answer 4

they act through cytokines to promote immune reactions

Question 5

Cytokines signal what?

Answer 5

B-cells

Question 6

What are the two subclasses of T-helper cells?

Answer 6

T-helper 1
T-helper 2

Question 7

Which T-helper cell is less specific?

Answer 7

T-helper 1

Question 8

How do T-helper 1 cells work?

Answer 8

they attract and activate macrophages for non-specific cellular defense
initiate inflammation

Question 9

How do T-helper 2 cells work?

Answer 9

stimulate B-cells to produce antibodies
very specific

Question 10

How do natural killer cells work?

Answer 10

they have no memory but recognize any foreign cells and kill the entire cell

Question 11

Natural killer cells are an effective defense against what cells?

Answer 11

cancer and virus infected cells

Question 12

What cells make antibodies?

Answer 12

B-cells

Question 13

Where are antibodies found?

Answer 13

serum, milk, and gastric secretions

Question 14

How do B-cells work?

Answer 14

antibodies on cell surface interacts with antigens & B-cell uses phagocytosis to ingest pathogen

Question 15

Antibodies are also known as what?

Answer 15

immunoglobulins

Question 16

What is the structure of antibodies?

Answer 16

two heavy chains
two light chains

Question 17

What fragments of antibodies can bind antigens?

Answer 17

Fab fragments (top 2 parts of the Y shaped antibody)

Question 18

What fragments of antibodies cannot bind antigens?

Answer 18

Fc fragment (bottom stem of the Y shaped antibody)

Question 19

What is the protease that digests the antibody into its 3 fragments?

Answer 19

papain

Question 20

What part of the Fab fragment on an antibody actually binds the antigen?

Answer 20

variable region
it varies from antibody to antibody

Question 21

What are the 5 types of antibodies?

Answer 21

IgG
IgM
IgA
IgE
IgD

Question 22

Which type of antibody is found in secretions from mucous membranes?

Answer 22

IgA

Question 23

Which types of antibodies are found in blood?

Answer 23

IgG and IgM

Question 24

Which type of antibody is found in serum & is involved in parasite immunity & allergies?

Answer 24

IgE

Question 25

Which type of antibody is found on the surface of B-cells?

Answer 25

IgD

Question 26

What is the most common antibody?

Answer 26

IgG

Question 27

Structure of IgG antibody

Answer 27

2 long heavy chains 2 short light chains heavy and light chains held together by disulfide bonds Y shaped

Question 28

Structure of IgM antibody

Answer 28

5 antibody molecules hooked together by J-chains

Question 29

What is the first antibody to be made in response to bacterial infection?

Answer 29

IgM

Question 30

Structure of IgA antibody

Answer 30

2 antibody molecules held together by a J-chain

Question 31

Structure of IgE antibody

Answer 31

have an extra constant region look like IgG

Question 32

Structure of IgD

Answer 32

look like IgG

Question 33

What are opsonins?

Answer 33

a substance that binds to foreign cells & makes them more susceptible to phagocytosis

Question 34

What is opsonization?

Answer 34

an immune process that uses opsonins to tag foreign pathogens

Question 35

What is complement activations mode of action?

Answer 35

1. antibodies destroy foreign cells by forming holes in the membrane 2. phagocytosis 3. attract macrophages & neutrophils through chemotaxis 4. inflammation

Question 36

Define inflammation

Answer 36

a nonspecific response to toxins that is mediated by the release of cytokines & chemokines is localized to the site of infection

Question 37

What are the consequences of immune responses?

Answer 37

inflammation septic shock hypersensitivity

Question 38

Define septic shock

Answer 38

a severe inflammatory response that spreads through the entire body often caused by gram negative bacteria

Question 39

What mediates type 1 (immediate) hypersensitivity?

Answer 39

IgE antibody

Question 40

What are some immediate hypersensitivity allergens?

Answer 40

pollen insect venom certain foods dust animal dander

Question 41

Describe type 1 (immediate) hypersensitivity

Answer 41

reaction occurs minutes after exposure to antigen

Question 42

Describe type 2 hypersensitivity

Answer 42

IgG antibodies work against LOCAL antigens

Question 43

Describe type 3 hypersensitivity

Answer 43

IgG antibodies work against CIRCULATING antigens

Question 44

Describe type 4 (delayed) hypersensitivity

Answer 44

TH1 helper cells produced inflammatory responses that CAUSED tissue damage symptoms appears hours after secondary exposure to antigens

Question 45

What are superantigens?

Answer 45

class of ANTIGENS that can activate an excessive amount of T-cells

Question 46

Describe active immunity

Answer 46

immune response that is stimulated by the presence of an antigen causes permanent change

Question 47

Describe natural active immunity

Answer 47

immunity following recovery from a disease

Question 48

Describe artificial active immunity

Answer 48

induced by injection of antigen-immunization

Question 49

Describe passive immunity

Answer 49

temporary immunity due to the presence of antibodies made by another person

Question 50

Describe natural passive immunity

Answer 50

infants receive antibodies from their mother through milk

Question 51

Describe artificial passive immunity

Answer 51

induced by injections of pre-formed antibodies

Question 52

What happens during netosis?

Answer 52

neutrophils self destruct & release NET to stop spread of pathogen

Question 53

What is the inflammasome?

Answer 53

a complex that senses the presence of nucleic acids from pathogens

Question 54

What allows for the evolutionary progression of cancer?

Answer 54

cancer cells grow too fast, do not die, have independence from the environment, migrate, and have access to nutrient supply

Question 55

What is metastasis caused by?

Answer 55

uncontrolled cell growth & evasion of apoptosis

Question 56

What causes uncontrolled proliferation (cell division) generating a malignant cell?

Answer 56

mutation in APC suppressor gene active Ras protein loss of p53 suppressor gene

Question 57

Production of which 2 proteins cause rapid tumor expression?

Answer 57

MYC and RasV12

Question 58

What are the 3 steps of apoptosis?

Answer 58

1. membrane forms irregular buds called blebs 2. membrane protrusions form 3. cell breaks apart into multiple apoptotic bodies

Question 59

What apoptotic caspases are initiator caspases that send signals to active executioner caspases when the cell is under stress?

Answer 59

2, 8, 9, 10

Question 60

Which apoptotic caspases are executioner caspases that degrade cell components?

Answer 60

3, 6, 7

Question 61

What is pyroptosis?

Answer 61

form of programmed cell death that induces an immune response

Question 62

When does pyroptosis happen?

Answer 62

in response to microbial infections & heart attacks

Question 63

What are PDL proteins?

Answer 63

programmed cell death proteins that can bind to PD1 protein on T-cell & trigger apoptosis