Lecture 17 Unit 3

Question 1

what is innate immunity

Answer 1

bodys lines of defense against invasion by pathogens

Question 2

what are the 4 types of innate immunity

Answer 2

1. physical barriers
2. fever
3. inflammation
4. cells and chemicals

Question 3

what is adaptive immunity

Answer 3

bodys ability to recognize and defeat a specific invading agents such as bacteria, viruses, and foreign tissues

Question 4

what are the two properties that allow us to distinguish innate immunity from adaptive immunity?

Answer 4

1. specificity for particular foreign molecules and tolerance for self proteins
2. memory of previously encountered foreign antigens so that the 2nd exposure prompts a more rapid and vigorous response

Question 5

how many genes are in the human genome

Answer 5

20,000

Question 6

how many proteins do cells make from instructions in our genes?

Answer 6

more than 250,000

Question 7

how can human and bacterial protein sequences be distinguished?

Answer 7

is the amino acids chain is more than 8 amino acids

Question 8

what do residual bodies tell us?

Answer 8

1. about things present in extracellular fluid

2. especially if what was destroyed was truly something foreign

Question 9

What do MHC proteins do

Answer 9

they display information in the form of peptides (pieces of protein) to the immune system

Question 10

what do MHC class 2 proteins do?

Answer 10

presented antigen is from protein components of materials engulfed and digested by phagocytes

Question 11

what is the result of MHC II actions?

Answer 11

MHC II displays extracellular antigen

Question 12

what do helper T-cells do?

Answer 12

they have T cell receptors whose job it is to interact with MHC II presented antigen

Question 13

how do all nucleated cells present antigen?

Answer 13

via MHC I

Question 14

what happens to any cell that refuses to share informations with the immune system

Answer 14

it is killed by natural killer cells

Question 15

what is the only thing that can inspect a MHC I presented antigen?

Answer 15

the T cell receptor of a T cell

Question 16

what does the T cell receptor allow the T cell to do?

Answer 16

enables a T cell to determine if presented antigen is one’s own (self) or belongs to another organism (non self)

Question 17

What does the T cell look for?

Answer 17

a unique presented antigen

Question 18

how is a T cell born with a unique TCR

Answer 18

genetic recombination of a series of gene segments that code for chains/subunits of TCRs leaves to a one of a kind TCR for each newly born T cell in the bone marrow

Question 19

how many TCRs does each T cell have and where?

Answer 19

each T cell has about 10^5 TCRs in its plasma membranes and all its daughter cells will have the same unique TCR gene

Question 20

what is recognition?

Answer 20

tight binding between antigen and TCR

Question 21

what does recognition do?

Answer 21

initiate an immune response

Question 22

why are only certain T cells with unique TCRs permitted to be in circulation?

Answer 22

it is dangerous it improperly activated

Question 23

What does the thymus do?

Answer 23

activates certain T cells

Question 24

where do all lymphocytes originate?

Answer 24

red bone marrow

Question 25

what does the maturation of a lymphocyte into a B cell or a T cell depend on?

Answer 25

where in the body it becomes immunocompetent

Question 26

where do B cells fully mature?

Answer 26

bone marrow

Question 27

where do T cells mature?

Answer 27

in the thymus under selection pressures

Question 28

how do T cells and B cells mature?

Answer 28

under negative and positive selection pressures

Question 29

what is negative selection?

Answer 29

eliminates T cells that are strongly anti-self

Question 30

what is positive selection

Answer 30

selects T cells with a weak response to self-antigens which thus become both immunocompetent and self tolerant

Question 31

all antigen is from what?

Answer 31

our own proteins