Cell recognition and the immune system Flashcards
1
Q
What is the biological name for white blood cells
A
Leukocytes
2
Q
What are the 3 types of white blood cells, only 2 on spec
A
- Granulocytes (not on spec)
- Phagocytes
- Lymphocytes
3
Q
What are the 2 types of phagocytes
A
- Neutrophil
- Macrophage
4
Q
What is the name of a macrophage before it’s developed
A
Monocyte
5
Q
What are the 2 types of lymphocytes
A
- B cell
- T cell
6
Q
What does a B cell mature into
A
Plasma cell
7
Q
What does a T cell mature into
A
- Either T helper cell
- Cytotoxic cell
8
Q
What type of stem cells are the ones found in bone marrow
A
Multipotent
9
Q
What does a multipotent stem cell mean
A
The stem cell can only differentiate into a certain type of cell e.g. blood cells but can differentiate into any type of blood cell
10
Q
Why don’t phagocytes provide immunity
A
Because they don’t have memory cells so they just destroy pathogens but don’t remember them
11
Q
What type of white blood cells are part of the non-specific immune response
A
- Granulocytes (not on spec)
- Phagocytes
12
Q
What are lymphocytes capable of recognising
A
- Self and non-self recognition
- Can differentiate cells that belong to the individual and those that are foreign
13
Q
What type of white blood cell is part of the specific immune response and why
A
Lymphocytes because they have memory
14
Q
What type of white blood cell provide immunity and why
A
Lymphocytes because they have memory
15
Q
What shape nucleus does a neutrophil have
A
Lobe shape
16
Q
What shape nucleus does a macrophage have
A
C shaped
17
Q
What shape nucleus does a lymphocyte have
A
Nearly the entire cell is covered by nucleus
18
Q
What type of leukocytes are antigen presenting cells
A
- Macrophage
- Lymphocytes
19
Q
Which division process do immature T cells undergo, and what does this produce
A
Mitosis, producing genetically identical cells- clone
20
Q
Where do T cell mature
A
In the thymus
21
Q
What is produced when a T cell matures
A
Cell receptors
22
Q
What type of biological molecule are the cell receptors on a T cell
A
Protein, tertiary structure
23
Q
What are the 2 possible types of T cell after they have matured
A
- T helper cells
- Cytotoxic cells
24
Q
When a T cell matures what is different on each T cell
A
The receptors
25
What division process do immature B cells divide by
Mitosis- producing genetically identical cells called a clone
26
Where do B cell mature
In the bone marrow
27
When B cell mature what do they produce
Antibody receptors
28
What type of biological molecule is the antibody receptor produced in the maturation of B cells
3D, Globular protein
29
Where are the 2 places where mature B cell circulate to
- Liver
- Spleen
30
When B cell mature what is different between each B cell
The antibody receptors
31
What are the 7 examples of barriers in immunity
- Skin
- Tears
- Saliva
- Sweat
- Stomach acid
- Mucus
- Skin flora
32
How does skin act as a barrier
Contains collagen and keratin which are tough
33
How does tears, saliva and sweat act as a barrier
They contain an enzyme called lysozyme which disrupts bacterial walls
34
How does stomach acid act as a barrier
It denatures the proteins and kills the pathogen
35
How does mucus act as a barrier
It traps bacteria and waft it up the trachea and down into the stomach where the acid kills the bacteria
36
How does the skin flora act as a barrier
They compete with bad bacteria
37
What are the 4 actions that happen for a non-specific immune system
- Phagocytosis
- Blood clotting
- Fever
- Inflammation
38
How does blood clotting act as a line of defence in immunity
It prevents pathogens from entering the capillaries
39
How does a fever act as a line of defence in immunity
It increases the temperature to denture growth enzymes in pathogens
40
How does inflammation act as a line of defence in immunity
It increases the blood flow to the site of injury which helps carry more white blood cells - the immunity cells
41
What type of cells are involved in the specific immune system
Lymphocytes
42
What's the difference between immunity and resistance
Immunity produces antibodies to fight the pathogen whereas resistance is a tolerance of the pathogen or an ability to withstand .
Immunity you gain from being exposed to the certain pathogen whereas resistance isn't obtained the organism is born with it e.g. bacteria resist antibiotics
43
What are the 7 cells that have antigens
- Viral capsids
- Infected body cell
- Toxin
- Bacterial antigen
- Macrophage
- Transplanted organ
- Cancerous cell
44
What happens during clonal selection
The lymphocytes with the complementary receptor/ antibody to the antigen are selected
45
What happens during clonal expansion
The lymphocyte with the complementary receptor/ antibody to the antigen are cloned over and over by mitosis
46
What cells are involved in cellular response
T cells
47
What are the 3 types of T cells involved in cellular response
- T helper cells
- Cytotoxic T cells
- Memory T cells
48
During cellular response, what is the first thing that T helper cells do
They attach/ bind to the antigen on the antigen presenting cell - only the ones that are complementary to the antigens
49
During cellular response, what do the T helper cells do after they attach to the antigens
They divide by mitosis - clonal expansion
50
Once T helper cells have divided during cellular response, what is the final thing they do
They secrete cytokines which stimulate all other white blood cells
51
During cellular response, what do the T cytotoxic cells do first
The complementary cells attach to the antigen on the antigen presenting cell which activates them or they are activated via the T helper cells
52
After the complementary cytotoxic T cells bind to the antigens that they are complementary to, what do they then do
They divide by mitosis
53
Once cytotoxic T cells divide, what do they then do during cellular response
They then release perforin proteins - which create pores leading to cell lysis
54
What do perforin proteins do
They get inserted into the cell membrane of the infected cell or the bacteria cell and make a pore - which then allows water the enter the cell via osmosis which results in cell lysis
55
How long of T memory cells remain in the blood for
Decades
56
Why are T memory cells useful
So if the same antigen is encountered the response is much faster since there are already multiple cells with complementary receptors
57
What are the 3 types of B cells involved in humoral response
- B cells
- Plasma cells
- Memory B cells
58
What type of lymphocyte is involved in the humoral response
B cells
59
What is the first thing that B cells do during a humoral response
The complementary B cell attaches to the antigen on the antigen presenting cell - clonal selection
60
After B cells have been clonally selected, what is the next process
Clonal expansion, via mitosis
61
Once B cells have divided what do they then do
They differentiate into plasma cells
62
What are the 3 organelles that a plasma cell is packed with
- Mitochondria
- RER
- Golgi body
63
Why do plasma cells require a lot of mitochondria
To produce ATP for the synthesis of the antibodies and the secretion of the antibodies via exocytosis
64
Why do plasma cells require a lot of RER
For the synthesis of antibodies
65
Why do plasma cells require Golgi bodies
To package and secrete antibodies
66
What is the difference between B memory cells and T memory cells
B memory cells secrete a small number of antibodies even after the pathogen has gone whereas T memory cells just stay dormant in the blood
67
Why is there a longer lag time for the primary response than the lag time for the secondary response
Because clonal selection takes time to find the complementary antibody, then it takes time for clonal expansion
68
Why are you more likely to express symptoms during the primary response
Because it's a slower and weaker response - since it takes time for the complementary antibody to be found and then it takes for the antibody to be reproduced via mitosis
69
Why is there a steeper gradient for the antibody concentration for the secondary response compared to the primary response
There is faster antibody production
70
Why is there a higher maximum antibody concentration during the secondary response compared to the primary response, and why does this maximum concentration last longer than the primary's maximum concentration
Because the clone is bigger due to memory cells and then all the cells with the complementary antibodies divide via mitosis
71
What are the 2 circumstances when there is no secondary response
- When the first pathogen exposure was fatal (the organism dies)
- When the pathogen mutates it's antigen - antigenic variability on the same pathogen (e.g. the common cold)
72
What are the names of the 2 regions on an antibody
- Constant region
- Variable region
73
What are the 2 types of polypeptide chains on an antibody
- Heavy polypeptide chain
- Light polypeptide chain
74
What is the name of the bonds on an antibody
Disulphide bridges
75
What is the name of the site at the top of an antibody
The antigen binding site
76
What type of biological molecule is an antibody
Protein
77
What structure protein is an antibody
Globular, quaternary structure
78
What makes the region on an antibody variable, and where on the antibody is this region
Because it has a different amino acid sequence, its at the antigen binding site
79
Why do antibodies need to have variable regions
Because antibodies need to be complementary to different antigens and in order for this to be the case antibodies need to have different antigen binding sites and the variable region makes these sites different
80
How many types of antigens can one antibody bind to
One type
81
How many antigens can an antibody bind to at one time
2, there are 2 antigen binding sites
82
What are the 5 actions of antibodies
- Cause bacterial lysis
- Prevent pathogens entering host cells
- Coat pathogens to aid phagocytosis
- Deactivate flagella to aid phagocytosis
- Cause pathogens to agglutinate
83
What does it mean when pathogens agglutinate
They stick together - so they can be consumed at once
84
What word is motility fancy for
Swim
85
What are monoclonal antibodies
Artificial antibodies that are produced in a lab specific to one type of antigen only
86
How are monoclonal antibodies produced
- The specific antigen is injected into small mammals which stimulates a humoral response
- isolated the B plasma cells that secrete the antibodies that responded to the antigen
- Plasma cells fuse with myeloma cell
- Forming a hybridoma
- clone the hybridoma
87
What type of cell does the plasma B cell fuse with to make monoclonal antibodies
Myeloma
88
What is formed when a plasma B cell binds to a myeloma cell during the process of making monoclonal antibodies
Hybridoma
89
What type of response is stimulated in the small mammal once the antigen has been injected into them during the process of making monoclonal antibodies
Humoral response
90
What are the 2 types of monoclonal antibody treatments
- Direct
- Indirect
91
How does direct monoclonal antibody cancer treatment work
- You inject the patients cell into a small mammal - so the antibodies are specific to the individual
- So the antibodies are complementary to the cancer's antigens so they bind and this stops the uncontrolled cell division by mitosis
92
How does indirect monoclonal antibody therapy work
A cytotoxic drug is attached to an antibody that is complementary to the cancer's antigen so the cytotoxic drug only kills the cancerous cells instead of all the cells
93
What are the advantages of monoclonal antibody treatments
- Monoclonal antibodies are non-toxic
- Monoclonal antibodies are specific so a lower dosage is needed: meaning there are fewer side effects and its cheaper
94
When you reach this card look on the 2.4 powerpoint and look at the pregnancy testing with monoclonal antibodies
95
What does PSA stand for
Prostate Specific Antigen
96
In direct ELISA, what attaches to the well in the test plate
A monoclonal antibody that is specific to the antigen that is being tested for
97
In the direct ELISA, after the monoclonal antibodies attach to the well in the test plate, what happens
Wash the test plate to remove any unattached monoclonal antibodies
98
After washing the test plate to remove any unattached monoclonal antibodies the first time during the direct ELISA, what happens
You add the patients blood sample - if any of the antigens you're testing for are in the sample then they bind to the antibodies
99
After the patients blood sample if added to the test plate during direst ELISA, what happens
You wash the plate to remove any unattached antigens
100
After the plate is washed after adding the patients blood during direct ELISA, what happens
You add another monoclonal antibody that has an enzyme attached and then wash to remove any unattached antibodies
101
Why does the second monoclonal antibody need to have an enzyme attached during direct ELISA
It reacts with a colourless substrate to produce a coloured product and this shows a positive result
102
What are the 3 ethical issues of using monoclonal antibodies
- Small mammals are used to produce them and we induce diseases upon them
- Requires informed consent from patients (being aware of the good and the bad)
- Have been failed drug trials (people have gone into organ failure)
103
What are the 4 types of immunity
- Artificial active
- Natural active
- Natural passive
- Artificial passive
104
What induces artificial active immunity
Antigen injection
105
What induces natural active immunity
Having the disease/ encountering the pathogen
106
What induces natural passive immunity
Breastfeeding
Across from the placenta
107
What induces artificial passive immunity
Antibody injection
108
What type of immunity is obtained from an antibody injection, and why
Artificial passive immunity because it's deliberate exposure but no memory cells are produced since the B cells don't get activate
109
What type of immunity is obtained from an antigen injection, and why
Artificial active immunity because it's deliberate exposure and the B cells get activated to produce antibodies and memory cells are made
110
What is the difference between active and passive immunity
Active immunity activates the B cells to produce the organisms own antibodies and memory cells
Passive immunity is when antibodies are retrieved from somewhere else - e.g. an injection
111
What's the difference between artificial and natural immunity
Artificial immunity is when there's deliberate exposure to get immunity
Natural is when immunity is obtained through some kind of natural life process
112
What does an attenuated pathogen mean
A weakened pathogen
113
What is in a vaccine (6 options)
- Dead/ inactive pathogen
- Attenuated pathogen
- Antibodies
- Antigens
- Toxoids
- Live pathogens
114
What 2 things make a vaccine successful
- Antigen that's highly immunogenic (produces high concentration of antibodies/ triggers strong immune response)
- Only 1 antigenic type of pathogen (a none mutating pathogen)
115
What type of vaccine is the most effective, what type of pathogen inside the vaccine, and why
Live pathogen because it's living so it can continue to replicate so there's continuous exposure to the pathogen
116
What type of vaccine is the least effective, what type of pathogen inside the vaccine, and why
Dead pathogen since they can't replicate so there's limited exposure
117
Why are booster vaccines useful
They trigger a secondary response which increase the antibody concentration in the blood so increases the number of memory cells
118
What is herd immunity
The majority of the population are vaccinated to interrupt transmission of pathogen in population
119
Who is protected when there's herd immunity
Those who haven't been vaccinated are also protected
120
What is ring immunity
When the people around the infected individual are vaccinated
121
What type of virus is HIV
Retro virus
122
What is a retro virus
A virus that has RNA so has the enzyme reverse transcriptase
123
How many RNA strands does HIV contain
2 RNA strands
124
What does reverse transcriptase do
It uses an RNA template to make DNA copies
125
Where does the lipid double membrane come from in a HIV molecule
The host cells membrane
126
What cells are effected by HIV
T helper cells
127
After HIV attaches to the receptor proteins on the surface of the T helper cells, binding, what happens
Fusion occurs where the HIV membrane fuses with the T helper cell membrane allowing entry of viral capsid and contents
128
Once the HIV has fused with the T helper cell membrane what happens
Reverse transcription- uses viral RNA as template to make DNA
129
Once reverse transcriptase has happened to HIV, what occurs
Integration- The viral DNA enters the T helper cells nucleus and becomes inserted into the T helper cells DNA
130
How long does the HIV viral DNA stay in the T helper cells nucleus
For years and even decades
131
What is the name of the process, where the HIV viral DNA is activated and uses the T helper cell to synthesise viral proteins and viral RNA
Activation
132
After the HIV viral DNA has been activated, what happens
Assembly- viral proteins and RNA synthesised by the T helper cell moves towards the cell membrane and begin to assemble into HIV
133
After HIV has been assembled in the T helper cell, what occurs
Budding- HIV pushes itself out of T helper cell taking a section of the T helper cell's membrane with it
134
Why does continuous budding off of HIV from T helper cells, decrease the number of T helper cells
Since T helper cells continue to shrink since the HIV takes part of the membrane and because there are many T helper cells undergoing this the number of T helper cells decreases
135
Why does HIV spread
It gets into the T helper cells and these T helper cells undergo clonal expansion so divide by mitosis so the viral DNA is passed on into new cells
136
Can you die from AIDS
No, it's the weakened immune system that fails when the patients encounters a disease
137
Why are antibiotics not effective against HIV
Antibiotics work by preventing cell wall synthesis and viruses don't have a cell wall
138
What is phagocytosis
An example of the non-specific immune response. Where pathogens are engulfed and digested by phagocytes
139
What is the role of Helper T cells (4 things)
- Develop into memory cells
- Activate cytotoxic T cells
- Stimulate phagocytes to carry out phagocytosis
- Stimulate B cells to divide and secrete their antibodies
140
Describe how HIV is replicated (4 marks)
- Attachment proteins attach to receptors on helper T cell
- RNA enters cell
- Reverse transcriptase converts RNA to DNA
- Viral protein produced
- Virus particles assembled and released from cell
141
Describe how the HIV is replicated once inside helper T cell ( 4 marks)
- RNA converted into DNA using reverse transcriptase
- DNA inserted into helper T cell DNA
- DNA transcribed into HIV mRNA
- HIV mRNA translated into new HIV proteins for assembly into viral particles
142
Describe how a phagocyte destroys a pathogen present in the blood (3 marks)
- Engulfs
- Forming phagosome and fuses with lysosome
- Enzyme digests
143
Give 2 types of cells, other than pathogens, that can stimulate an immune response
- Cells from other organisms/ transplant
- Abnormal/ cancer / tumour
- Cells infected by virus
144
Explain how HIV affects the production of antibodies when AIDS develops in a person ( 3 marks )
- Less/ no antibody produced
- Because HIV destroys helper T cells
- So few/ no B cells activated/ stimulated
145
Determining the genome of the viruses could allow scientists to develop a vaccine. Explain how. ( 2 marks)
- The scientists could identify proteins
- They could then identify potential antigens
146
Describe how the B lymphocytes of a frog would respond to a vaccination against a virus, assuming B cells act as they do in humans (3 marks)
- B cells binds to viral, complementary antigen
- B cells clones
- Plasma cells release antibodies against the virus
- B cells produce memory cells
147
What is a monoclonal antibody
Antibodies with the same tertiary structure
148
Describe the role of antibodies in producing a positive result in an ELIZA test (4 marks)
- First antibody binds to antigen
- Second antibody with enzyme attached is added
- Second antibody attaches to antigen
- Substrate added and colour changes
149
Describe and explain the role of antibodies in stimulating phagocytosis (2 marks)
- Binds to antigen
- Antibodies cause aggluntination
150
Describe how phagocytosis of a virus leads to presentation of its antigens ( 3 marks)
- Phagosome fuses with lysosome
- Virus destroyed by lysozymes
- Antigens are displayed on the cell membrane
151
Describe how presentation of a virus antigen leads to the secretion of an antibody against this virus antigen (2 marks)
- Helper T cells binds to the antigen
- This helper T cells stimulate to a specific B cell
- B cell clones
- Forms plasma cells that release antibodies
152
What is an antigen (2 marks)
- Foreign protein
- That stimulates an immune response
153
What is an antibody (2 marks)
- A protein specific to an antigen
- Produced by B cells
154
Describe how vaccination can lead to protection against bacterial meningitis ( 6 marks )
- Antigen binds to surface protein on a B cell
- Activated B cell divides by mitosis
- Division stimulated by T cells
- B cells/ plasma cells release antibodies
- Some B cells become memory cells
- Memory cells produce plasma/ antibodies faster
155
When a vaccine is given to a person, it leads to the production of antibodies against a disease-causing organism. Describe how. (5 marks)
- Vaccine contains antigen from pathogen
- Macrophage presents antigen on its surface
- T cell with complementary receptor protein binds to antigen
- T cells stimulate B cells
- With complementary antibody on its surface
- B cell secretes large amounts of antibody
- B cell divides to form clone all secreting same antibody
156
Describe the difference between active and passive immunity (5 marks)
- Active involves memory cells, passive does not
- Active involves production of antibody by plasma cells/ memory cells
- Passive involves antibody introduced into body from outside
- Active long term, becuase antibody produced in response to antigen
- Passive short term, because antibody given is broken down
- Active can take time to develop / work, passive fast acting
