Defenses and Immunity - Adaptive Immunity and Pathogens

Question 1

In contrast to treating diseases, some _____ _____ disease.

Answer 1

Antibodies cause

Question 2

An antigen from the environment enters body, how does the body react?

Answer 2

The body produces antibodies against the antigen. These antibodies coat specialized cells called mast cells.

Question 3

If you encounter the same antigen again, how does your body react?

Answer 3

The antigens attach to antibodies coating mast cells. When these mast cells detect the antigen, they release large quantities of a molecule called histamine.

Question 4

What do histamines cause?

Answer 4

Inflation, runny nose, and congestion- symptoms of an allergic response

Question 5

True or False:

Antibodies can cause autoimmune diseases.

Answer 5

True

Question 6

What is an autoimmune disease?

Answer 6

“Rouge” immune cells attack “self” cells

Question 7

What do B cells do within the immune system?

Answer 7

B cells help eliminate antigens or microorganisms that are outside of cells

Question 8

What do T cells do?

Answer 8

T cells help eliminate microorganisms or viruses that are inside of a cell

Question 9

How does a T cell “know” what is going on within a cells?

Answer 9

All cells present cytoplasmic antigens (usually short peptides) on their surface using carrier proteins called MHC molecules.

Question 10

How does a T cell ‘deal with’ cells that are presenting a foreign antigen?

Answer 10

• A cytotoxic T cell binds to an infected cell
• Perforin makes holes in the infected cell’s membrane, and enzymes that promote cell death enter.
• The infected cell is destroyed (lysed)

Question 11

Rather than killing cells, _____ __ cells help other cells fight invaders more effectively.

Answer 11

Helper T

Question 12

How do dendritic cells activate helper T cells?

Answer 12

• Dendtritic cells swallow microbes and chop them up into antigens
• Antigens from the microbe are loaded onto MHC molecules
• These MHC molecules are displayed on the cell’s surface
• Helper T cells can now come along and use their antigen receptors to bind the MHC molecule

Question 13

Once activated, what do helper T cells do?

Answer 13

• Activated helper T cells release signals that help them divide, generating many helper T call clones
• Some of these cells help activate B cells
• Other helper T cells stimulate cytotoxic T cells

Question 14

Helper T cells play a critical role in ________ nearly all aspects of a/an _____ _______ response.

Answer 14

Coordinating; adaptive; immune

Question 15

How do cytotoxic and helper T cells differ?

Answer 15

Cytotoxic T cells express a T-cell receptor that only recognizes class I MHC molecules displaying a foreign peptide; helper T cells express a T-cell receptor that only recognizes class II MHC molecules

Question 16

Define MHC-I:

Answer 16

Large alpha chain paired with beta2-microglobulin, alpha chain forms the peptide- bonding groove

Question 17

Define MHC-II:

Answer 17

Alpha chain paired with beta chain, Peptide-binding groove is formed by the interface between the two chains

Question 18

MHC-I is in all ____ cells (makes sense: any _____ cells can be infected)

Answer 18

Nucleated; nucleated

Question 19

MHC-II is in only ________ _______-______ cells (makes sense: these are the only cell types that communicate with helper T cells)

Answer 19

Professional antigen-presenting

Question 20

By loading _____ from different compartments onto different ____ molecules, the immune system can detect there a _____ came from.

Answer 20

Peptides; MHC; peptide

Question 21

True or False:
This is the correct order of events:
(cytoplasmic peptide->MHC-I ->cytotoxic T cell -> cell death

Answer 21

True

Question 22

True or False:
This is the correct order of events:
(Extracellular peptide -> MHC-II -> helper T cell -> assistance to B cells and other fighting EXTRACELLULAR pathogens

Answer 22

True

Question 23

The T cell ____ binds to the _____ plus the _____ molecule that is presenting it

Answer 23

Receptor; peptide; MHC

Question 24

What are the properties of CD8?

Answer 24

Membrane protein expressed by cytotoxic T cells, Binds MHC-I and not MHC-II

Question 25

The fact that CD8 only binds to MHC-I ensures:

Answer 25

that the cytotoxic T cell’s receptor only recognizes MHC-I

Question 26

What are the properties of CD4?

Answer 26

Membrane protein expressed by helper T cells, binds MHC-II and not MHC-I

Question 27

The fact that CD4 only binds to MHC-II ensures:

Answer 27

That the helper T cell’s receptor only recognizes MHC-II

Question 28

Each __ or ___ cell has a unique, ________ ________ receptor.

Answer 28

B; T; Randomly Generated