14.0

Question 1

What is an infection?

Answer 1

Pathogenic microorganisms penetrate hosts and multiply

Question 2

What is another name for a virus?

Answer 2

Obligate intracellular parasites: rely on infecting host and using its machinery to replicate and live.

Question 3

A fully assembled infectious virus is called

Answer 3

virion

Question 4

What is the structure of a virus?

Answer 4

protein shell[capsid] surrounding nucleic acid core[DNA/RNA]

Question 5

Difference between HIV, Papilloma virus
poxvirus

Answer 5

-HIV: enveloped, outer phospholipid/glycoprotein coat
-Papilloma virus: Naked: (no envelope)
-Poxvirus: Complex, have extra structures

Question 6

Fill it in:
Virus: Possess only the ___needed to ___a host cell and
___ its activity

Answer 6

genes, invade, redirect

Question 7

HIV

Answer 7

-enveloped retrovirus [ single-stranded RNA genome that uses a reverse transcriptase to store its genetic info as DNA that is then integrated into the host using an integrase enzyme]
-Once integrated, the viral DNA is referred to as a provirus.

Question 8

Shingles is the result of what?

Answer 8

dsDNA virus, after recovery from chickenpox it can lie dormant in the nervous system, later its activated and travels along nerve pathways to the skin

Question 9

Damage as result of viral infection is …
What are some examples?

Answer 9

Cytopathic Effects[CPE]
Syncytium: mass multinucleated cell
Inclusion: body suspended in cytoplasm

Question 10

Bacteria

Answer 10

produce toxins that disrupt cell function
Ex: Cholera toxin: bacteria caused the small intestine to release large amounts of water into the large intestine causing diarrhea and dehydration

Question 11

What is penicillins?

Answer 11

it is an antibiotic that inhibits formation of bacterial cell wall

Question 12

What is tetracyclines?

Answer 12

it is an antibiotic, inhibit protein synthesis of bacteria

Question 13

What is quinolines?

Answer 13

it is an antibiotic, that blocks DNA grac which is responsible for the unwinding of DNA, unable to do so means bacteria can’t replicate

Question 14

How does our body fight off infections?

Answer 14

-skin resist pathogen insertion
-an acidic environment like the stomach kills bacteria
-specificity of viruses to host cell receptors
-lysozyme: damages bacterial cell walls[saliva]
-mucous membrane: chemical viral inhibitors, prevent attachment
-innate immune system, like phagocytosis
-adaptive/acquired immune system

Question 15

What is the innate immune system?

Answer 15

nonspecific, acts sooner than specific responses, occurs in response to general components of pathogens or to factors released by damaged cells.

Question 16

What are DAMPs?

Answer 16

cells are damaged or die, they release DAMPs which can bind to

Question 17

What 3 systems can activate the innate immune system?

Answer 17

1. PAMPs, pathogen-associated molecular compounds
   2.DAMPs, damage-associated molecular compounds
   3.PRRs pattern recognition receptors

Question 18

What are PRR?

Answer 18

Are receptors found on certain immune cells, such as phagocytic cells. They are responsible for identifying and binding to PAMPs and DAMPs
Ex: TLR(Toll Like Receptors) usually expressed on sentinels

Question 19

What are sentinel cells?

Answer 19

Sentinel cells are immune cells that act as the first line of defense against pathogens.

Question 20

What are PAMPs?

Answer 20

Found on pathogens, that are recognizable by pattern recognition receptors (PRR) on immune cells, binds it activates innate immune system
Ex: lipopolysaccharide (LPS) found on outer bacterial membrane

Question 21

What are the 4 innate immune responses?

Answer 21

Inflammation
Phagocytosis
Interferon
Complement

Question 22

What is inflammation

Answer 22

innate immune response
interferes with further pathogen
replication/multiplication

Question 23

Chemokine

Answer 23

When there is tissue damage or infection, cells at the site release chemokines, which act as chemical signals. These chemokines attract immune cells, such as neutrophils and monocytes, to the site through a process called chemotaxis. The

Question 24

chemotaxis

Answer 24

tendency of cells to migrate in response to a chemical stimulus
-Monocytes are attracted to a damaged site

Question 25

function of histamine

Answer 25

Histamine increases the permeability of the capillaries to white blood cells and some proteins, to allow them to engage pathogens in the infected tissues.

Question 26

What are the stages of inflammation?

Answer 26

1. bacteria enters through skin 2.histamine release 3.histamines+ cytokines filate local blood vessels 4. chemokines attract neutrophils, which pass b/w cells of blood vessel wall 5. neutrophils engulf the pathogens and destroy them

Question 27

During inflammation, chemical mediators help cause fever, stimulate white blood cells (wbc=leukocyte), which prevent the spread of the pathogen. What are some examples?

Answer 27

TNF (chemotaxis, phagocytosis), IFN (inhibits virus replication), IL (activate wbc)

Question 28

IFN

Answer 28

Stands for Interferon Binding of a virus to a host cell initiates IFN synthesis, IFN is secreted by the cell into the extracellular space, Binds to another host cell, Induces production of proteins, Degrade viral RNA or prevent translation of viral proteins -Not virus-specific

Question 29

Phagocyte

Answer 29

A class of white blood cells capable of engulfing other cells and particles types: -Neutrophils-a type of granulocyte, short lived -Monocytes -Macrophages

Question 30

phagocytosis

Answer 30

Type of endocytosis: cell membrane actively engulfs large particles or cells into vesicles

Question 31

What is cytokine?

Answer 31

Signaling molecules produced by the immune system, play a crucial role in cell communication during immune responses. Examples of cytokines include interferons, interleukins, and tumor necrosis factors.

Question 32

What is pyrogen?

Answer 32

Pyrogen is a polypeptide that can induce fever by causing metabolic changes in the hypothalamus, which is the part of the brain that regulates body temperature. Pyrogens can be exogenous, meaning they are produced by infectious agents, or endogenous, meaning they are produced by cells in the body such as macrophages.

Question 33

What are macrophages?

Answer 33

Macrophages are a type of white blood cell that is capable of engulfing and digesting other cells and particles. They are part of the innate immune system.

Question 34

Fever can ..

Answer 34

inhibits multiplication of temperature sensitive viruses

Question 35

Stem cells in the bone marrow can become...

Answer 35

1. Granulocytes- class of wbc, have granules in their cytoplasm, neutrophils, eosinophils, and basophils. 2. Monocytes- class of wbc, go to infection site and differentiate into macrophages and dendritic cells 3. lymphocytes- class of wbc Ex: natural killer cells (NK cells), T cells, B cells; are predominantly found in the lymph.

Question 36

For lymphocytes, during development B cells stay in the ... T cells migrate to the..

Answer 36

bone marrow, thymus

Question 37

Difference between T cells and B cells?

Answer 37

cells directly attack infected or cancerous cells, while B cells produce antibodies to neutralize pathogens and mark them for destruction.

Question 38

What are complement?

Answer 38

Nonspecific group of proteins found in the blood plasma that forms a membrane attack complex that kills cells by creating holes in the membrane

Question 39

RNA interference (RNAi)

Answer 39

Cellular mechanism, destroys viral dsRNA, inhibits virus life cycle.

Question 40

Natural killer (NK) cells

Answer 40

(lymphocytes, not phagocytes) Can be activated by interferon -Secrete perforin: creates pores in target cell, ruptures infected cells -Secrete enzymes to degrade DNA, trigger apoptosis (programmed cell death)