front 1 Which organ normally produces most complement proteins? | back 1 B. Liver |
front 2 A researcher measures complement proteins in serum. Which protein
should be most abundant? | back 2 D. C3 |
front 3 In the alternative complement pathway, C3 is continuously split into
which products? | back 3 A. C3a and C3b |
front 4 Which C3 fragment is highly reactive after spontaneous C3
breakdown? | back 4 C. C3b |
front 5 C3b rapidly binds chemical groups on nearby bacterial surfaces. Which
groups are targeted? | back 5 A. Amino or hydroxyl |
front 6 If C3b fails to bind a target group quickly, it is neutralized. What
is the approximate time window? | back 6 D. 60 microseconds |
front 7 Free C3b that misses a bacterial surface is neutralized by which
molecule? | back 7 B. Water |
front 8 After C3b stabilizes on a bacterial surface, which complement protein
binds next? | back 8 C. B |
front 9 After factor B binds stabilized C3b, which protein clips factor
B? | back 9 A. D |
front 10 Cleavage of factor B on surface-bound C3b forms which
complex? | back 10 D. C3bBb |
front 11 C3bBb enzymatically cleaves additional C3 molecules. What type of
enzyme is C3bBb? | back 11 B. Convertase |
front 12 In the alternative pathway, C3bBb primarily cleaves which complement
protein? | back 12 C. C3 |
front 13 C3bBb generates more C3b, which can form more C3bBb. What does this
create? | back 13 A. Positive feedback |
front 14 C3bBb can bind another molecule to become a C5-cleaving complex.
Which molecule is added? | back 14 D. C3b |
front 15 The C3bBb-C3b complex cleaves which complement protein? | back 15 B. C5 |
front 16 C5 cleavage produces which two fragments? | back 16 A. C5a and C5b |
front 17 Which complement fragment initiates membrane attack complex
assembly? | back 17 C. C5b |
front 18 C5b combines with which proteins to form the MAC? | back 18 D. C6, C7, C8, C9 |
front 19 In MAC formation, which components form the membrane-anchoring
stalk? | back 19 B. C5b, C6, C7, C8 |
front 20 Which MAC component forms the membrane pore? | back 20 A. C9 |
front 21 A gram-negative bacterium dies after complement forms a pore through
its membrane. Which outcome occurred? | back 21 C. Bacterial lysis |
front 22 Spontaneous C3 breakdown is central to which pathway? | back 22 D. Alternative pathway |
front 23 In the alternative pathway, what happens immediately after C3b
stabilizes on bacteria? | back 23 A. B binds C3b |
front 24 In the alternative pathway, what does factor D do? | back 24 B. Cleaves bound B |
front 25 What is the main enzymatic function of C3bBb? | back 25 C. Cleaves C3 |
front 26 What is the main enzymatic function of C3bBb-C3b? | back 26 D. Cleaves C5 |
front 27 Which sequence best describes terminal MAC assembly? | back 27 A. C5b recruits C6-C9 |
front 28 Human cells avoid complement injury partly because blood enzymes
inactivate which molecule? | back 28 C. C3b |
front 29 Which cell-surface protein accelerates C3b inactivation? | back 29 B. MCP |
front 30 What is the role of membrane cofactor protein? | back 30 D. Accelerates C3b inactivation |
front 31 Which cell-surface protein accelerates C3bBb destruction? | back 31 A. DAF |
front 32 Decay accelerating factor protects host cells by promoting which
event? | back 32 C. C3bBb destruction |
front 33 CD59 is also known by which name? | back 33 B. Protectin |
front 34 CD59 protects host cells by preventing which event? | back 34 D. C9 attachment |
front 35 The central recognition molecule in the lectin pathway is which
protein? | back 35 A. MBL |
front 36 Mannose-binding lectin is central to which activation
pathway? | back 36 C. Lectin |
front 37 In blood, mannose-binding lectin binds which associated
protein? | back 37 B. MASP |
front 38 In the lectin pathway, MBL attaches to which bacterial surface
sugar? | back 38 D. Mannose |
front 39 In the lectin pathway, which component acts as the
convertase? | back 39 A. MASP |
front 40 In the lectin pathway, MASP clips which complement protein? | back 40 C. C3 |
front 41 The classical pathway depends on which immune molecule? | back 41 D. Antibody |
front 42 Which pathway is antibody-independent? | back 42 B. Alternative pathway |
front 43 C3b can be clipped into an inactive opsonin. What is it
called? | back 43 A. iC3b |
front 44 Which statement best describes iC3b? | back 44 C. Inactive opsonin |
front 45 iC3b still helps immune defense mainly by promoting which
process? | back 45 B. Opsonization |
front 46 Which complement fragments help form MACs? | back 46 D. C3b and C5b |
front 47 Which complement fragments act as chemoattractants? | back 47 A. C3a and C5a |
front 48 C3a and C5a recruit immune cells toward inflammation. What is this
function called? | back 48 C. Chemotaxis |
front 49 Which complement fragment is especially powerful as a
chemoattractant? | back 49 B. C5a |
front 50 C5a is especially powerful at attracting which immune cells? | back 50 D. Macrophages |
front 51 C3a and C5a are also classified as what? | back 51 A. Anaphylatoxins |
front 52 C3a and C5a can contribute to which systemic reaction? | back 52 C. Anaphylactic shock |
front 53 Which cells are considered professional phagocytes? | back 53 D. Macrophages and neutrophils |
front 54 Which professional phagocyte acts as a sentinel cell in
tissues? | back 54 B. Macrophage |
front 55 Where are macrophage sentinel cells typically positioned? | back 55 A. Below exposed tissue surfaces |
front 56 Macrophage sentinels are especially found near tissues exposed to
what? | back 56 C. External environment |
front 57 A C3 molecule spontaneously breaks apart near a bacterial membrane.
Why must this occur very close to the target? | back 57 B. C3b is rapidly neutralized |
front 58 A tissue macrophage is primed by inflammatory cytokines and begins
presenting antigen to helper T cells. Which molecule is
upregulated? | back 58 C. Class II MHCs |
front 59 A resting macrophage becomes an antigen-presenting cell after
activation. What change best explains this? | back 59 A. Increased class II MHC |
front 60 A macrophage is exposed to IFN-gamma during infection. What is the
expected functional result? | back 60 D. Macrophage priming |
front 61 Which cytokine is best known for priming resting macrophages? | back 61 B. IFN-gamma |
front 62 IFN-gamma is produced mainly by which cells? | back 62 D. Helper T cells and NK cells |
front 63 A macrophage receives direct stimulation from bacterial
lipopolysaccharide. What state can it enter? | back 63 A. Hyperactivated |
front 64 Lipopolysaccharide is classically associated with which
bacteria? | back 64 C. Gram-negative bacteria |
front 65 A hyperactivated macrophage releases a cytokine that can kill tumor
cells and virus-infected cells. Which cytokine is this? | back 65 C. TNF |
front 66 TNF produced by hyperactivated macrophages can directly help kill
which target? | back 66 A. Virus-infected cells |
front 67 Besides killing abnormal cells, TNF also helps perform which
function? | back 67 D. Activate immune cells |
front 68 A hyperactivated macrophage increases intracellular organelles filled
with destructive enzymes. Which organelles increase? | back 68 B. Lysosomes |
front 69 A macrophage increases production of hydrogen peroxide during
hyperactivation. This represents increased production of what? | back 69 A. Reactive oxygen molecules |
front 70 A macrophage encounters a parasite too large to ingest. Which
hyperactivated ability helps attack it? | back 70 C. Lysosomal dumping |
front 71 Hyperactivated macrophages increase destructive potential through
which change? | back 71 B. More lysosomes |
front 72 Hyperactivated macrophages can damage pathogens using which
molecule? | back 72 D. Hydrogen peroxide |
front 73 A neutrophil leaves bone marrow. On average, when will it die? | back 73 A. About 5 days |
front 74 Compared with macrophages, neutrophils are generally not which type
of cell? | back 74 C. Antigen-presenting cells |
front 75 Which cells uniquely liquefy tissues with destructive enzymes during
infection? | back 75 B. Neutrophils |
front 76 A dying neutrophil releases web-like structures that trap bacteria
and fungi. What are these called? | back 76 C. NETs |
front 77 NETs can trap or kill which organisms? | back 77 B. Bacteria, viruses, fungi, parasites |
front 78 Before infection, endothelial cells display which adhesion
molecule? | back 78 B. ICAM |
front 79 Neutrophils normally carry which surface molecule for rolling? | back 79 A. Selectin ligand |
front 80 During infection, nearby macrophages release which cytokines to
activate endothelium? | back 80 C. IL-1 and TNF |
front 81 IL-1 and TNF cause endothelial cells to produce which molecule? | back 81 B. Selectin |
front 82 Selectin on endothelium binds which neutrophil molecule? | back 82 D. Selectin ligand |
front 83 Selectin binding to neutrophil selectin ligand causes what? | back 83 C. Neutrophil rolling |
front 84 While rolling, a neutrophil samples nearby tissue for which
signals? | back 84 A. Inflammatory signals |
front 85 Which inflammatory signal can a rolling neutrophil detect? | back 85 B. C5a |
front 86 Which bacterial signal can help activate a rolling neutrophil? | back 86 D. LPS |
front 87 After sensing inflammatory signals, neutrophils push which protein to
their surface? | back 87 A. Integrin |
front 88 Neutrophil integrin binds which endothelial molecule? | back 88 C. ICAM |
front 89 Integrin binding to ICAM causes which neutrophil behavior? | back 89 D. Full stopping |
front 90 A neutrophil firmly adheres to endothelium after integrin-ICAM
binding. What comes next? | back 90 B. Tissue exit |
front 91 Which chemoattractant encourages stopped neutrophils to enter
tissue? | back 91 A. C5a |
front 92 Bacterial protein fragments containing formyl methionine are also
called what? | back 92 C. f-met peptides |
front 93 f-met peptides help guide neutrophils toward which location? | back 93 D. Inflammation site |
front 94 In the neutrophil exit sequence, selectin mainly causes which
event? | back 94 B. Rolling |
front 95 In the neutrophil exit sequence, integrin mainly causes which
event? | back 95 A. Firm adhesion |
front 96 A macrophage detects gram-negative LPS before major adaptive
activation. Which receptor group enables detection? | back 96 B. Pattern-recognition receptors |
front 97 Pattern-recognition receptors are used by immune cells to recognize
what? | back 97 A. Invasion patterns |
front 98 Pattern-recognition receptors detect pathogen-associated molecular
patterns, also called what? | back 98 C. PAMPs |
front 99 Pattern-recognition receptors detect damage-associated molecular
patterns, also called what? | back 99 D. DAMPs |
front 100 LPS from gram-negative bacteria is an example of what? | back 100 B. PAMP |
front 101 Intracellular molecules released after cell death are examples of
what? | back 101 C. DAMPs |
front 102 Approximately how many receptor types are included among
Pattern-recognition receptors? | back 102 D. Over twenty |
front 103 Which PRR family is described as most studied? | back 103 B. Toll-like receptors |
front 104 How many Toll-like receptors are described in this material? | back 104 A. Ten |
front 105 Which Toll-like receptor detects lipopolysaccharide? | back 105 C. TLR4 |
front 106 TLR4 is anchored in which location? | back 106 B. Plasma membrane |
front 107 TLR4 points in which direction? | back 107 B. Outward |
front 108 Which TLR detects viral single-stranded RNA? | back 108 C. TLR7 |
front 109 TLR7 detects ssRNA from viruses such as which examples? | back 109 A. Influenza and HIV-1 |
front 110 Which TLR detects double-stranded DNA? | back 110 D. TLR9 |
front 111 TLR9 detects dsDNA from which sources? | back 111 B. Bacteria and herpes simplex |
front 112 TLR7 and TLR9 are located on which structure? | back 112 C. Phagolysosomes |
front 113 TLR7 and TLR9 point in which direction? | back 113 A. Inward |
front 114 Which molecule lets endothelium slow neutrophils during
inflammation? | back 114 B. Selectin |
front 115 A neutrophil exits blood by squeezing between endothelial cells. What
drives this movement? | back 115 C. Chemoattractant gradients |
front 116 PRRs often recognize pathogen structures that cannot easily change.
Why is this useful? | back 116 B. They are pathogen-essential features |
front 117 A pathogen mutates a PRR-recognized structural feature and becomes
nonviable. What does this demonstrate? | back 117 C. PRRs target essential structures |
front 118 The innate immune system’s primary defense against viruses is which
system? | back 118 B. Interferon system |
front 119 A virally infected cell’s PRRs detect viral material. Which warning
proteins are produced? | back 119 A. IFN-alpha and IFN-beta |
front 120 IFN-alpha and IFN-beta mainly interfere with which process? | back 120 B. Viral reproduction |
front 121 IFN-alpha and IFN-beta are classified as which interferon
type? | back 121 D. Type I |
front 122 IFN-gamma is classified as which interferon type? | back 122 B. Type II |
front 123 A cell binds IFN-alpha after nearby viral detection. What does it
begin producing? | back 123 A. Antiviral proteins |
front 124 Type I interferons bind virus-infected cells and induce which
response? | back 124 A. Antiviral protein production |
front 125 An uninfected cell binds interferon but has no viral attack. What
happens initially? | back 125 C. Business as usual |
front 126 An interferon-warned cell later becomes infected by virus. What is
the expected outcome? | back 126 B. Apoptosis |
front 127 Many cells can produce type I interferon, but which WBC produces the
most? | back 127 D. Plasmacytoid dendritic cell |
front 128 Plasmacytoid dendritic cells are especially important for producing
which molecules? | back 128 A. IFN-alpha and IFN-beta |
front 129 Natural killer cells defend against infections partly by producing
what? | back 129 A. Cytokines |
front 130 Which cytokine can natural killer cells produce? | back 130 B. IFN-gamma |
front 131 Besides cytokine production, NK cells defend by forcing target cells
into what process? | back 131 A. Apoptosis |
front 132 NK cells can inject suicide enzymes into target cells using which
protein? | back 132 A. Perforin |
front 133 Perforin helps NK cells deliver which molecules? | back 133 B. Suicide enzymes |
front 134 NK cells can also trigger apoptosis through which surface
ligand? | back 134 A. Fas ligand |
front 135 Fas ligand on an NK cell binds which target-cell protein? | back 135 B. Fas |
front 136 Fas-Fas ligand interaction causes the target cell to do what? | back 136 A. Self-destruct |
front 137 NK cells differ from T cells because NK cells lack what? | back 137 B. T-cell receptors |
front 138 Instead of T-cell receptors, NK cells use which receptor
types? | back 138 A. Activating and inhibitory |
front 139 NK activating receptors motivate the cell to do what? | back 139 B. Kill |
front 140 NK inhibitory receptors motivate the cell to do what? | back 140 A. Not kill |
front 141 The NK “don’t kill” signal comes from recognition of which
molecule? | back 141 B. Class I MHC |
front 142 The NK “kill” signal comes from recognition of unusual surface
what? | back 142 B. Carbohydrates/proteins |
front 143 Unusual foreign carbohydrates or proteins suggest a cell is stressed
by what? | back 143 A. Infection or cancer |
front 144 A virus hijacks a host cell and stops class I MHC production. Which
immune cell may miss it? | back 144 B. Killer T cell |
front 145 Why would a class I MHC-deficient infected cell evade killer T
cells? | back 145 A. No class I display |
front 146 A class I MHC-deficient infected cell is placed near an NK cell. What
happens? | back 146 C. NK likely induces apoptosis |
front 147 Why do NK cells kill cells with low class I MHC? | back 147 B. They lack inhibitory signal |
front 148 A cancerous cell has abnormal surface proteins but reduced class I
MHC. Which immune cell is well suited to kill it? | back 148 A. NK cell |
front 149 In NK-macrophage cooperation, bacterial LPS first binds which
cell? | back 149 B. NK cell |
front 150 After LPS stimulation, NK cells produce which macrophage-priming
cytokine? | back 150 A. IFN-gamma |
front 151 IFN-gamma from NK cells does what to macrophages? | back 151 A. Primes macrophages |
front 152 Primed macrophages can become hyperactivated by direct contact with
what? | back 152 B. LPS |
front 153 A hyperactivated macrophage produces which cytokine in this feedback
loop? | back 153 A. TNF |
front 154 After producing TNF, the macrophage responds by secreting which
cytokine? | back 154 A. IL-12 |
front 155 IL-12 plus TNF influences NK cells to increase production of
what? | back 155 A. IFN-gamma |
front 156 In the NK-macrophage loop, TNF increases NK-cell expression of which
receptor? | back 156 A. IL-2 receptors |
front 157 IL-2 acts as what for NK cells? | back 157 A. Growth factor |
front 158 IL-2 allows NK cells to do what? | back 158 A. Proliferate |
front 159 In the NK-macrophage loop, which cytokine primes macrophages? | back 159 B. IFN-gamma |
front 160 In the NK-macrophage loop, which cytokine helps induce IL-12
release? | back 160 A. TNF |
front 161 delete | back 161 delete |
front 162 After IFN-gamma primes macrophages, what can LPS directly
trigger? | back 162 A. Hyperactivation |
front 163 Which two cytokines together increase NK IFN-gamma output? | back 163 A. IL-12 and TNF |
front 164 Which cytokine causes NK cells to upregulate IL-2 receptors? | back 164 A. TNF |
front 165 Activated macrophages can produce which complement protein? | back 165 A. C3 |
front 166 Activated macrophages can produce C3 and which factors? | back 166 A. Factors B and D |
front 167 Complement proteins start being made during which fetal
period? | back 167 A. First trimester |