Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology Paper 1 > Cells: Cell recognition and the immune system > Flashcards

Cells: Cell recognition and the immune system Flashcards

1
Q

What is antigen?

A

A protein in the cell surface membrane that triggers an immune response.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where are B cells produced?

A

Bone marrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are non-self cells?

A

Not our body’s cells and molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Name two pathogens can stimulate an immune response:

A
  • Virus
  • Bacterium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the two types of phagocytes?

A

Neutrophils
Macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does a neutrophil do?

A

Engulfs and digests pathogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does a macrophage do?

A
  • Punch holes in bacteria.
  • Stick proteins to the outside of bacteria to make them more appealing for the neutrophils to destroy.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is phagocytosis?

A

Engulfing pathogens.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe how phagocytes destroy non-self antigens in the blood:

A

1) Complementary protein receptors on the cell-surface membrane of the phagocyte binds to non-self antigens.
2) Cell membrane forms around the pathogen, engulfing it.
3) The pathogen is internalised in a phagosome.
4) Lysosomes fuse with the phagosome, releasing lysozymes, which digest the pathogen.
5) Non-self antigens are presented on the cell-surface membrane of the phagocyte.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why must patients who receive organ donations take anti-rejection medicines?

A

Donor cells are non-self antigens, which will be destroyed by phagocytes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

State the four types of non-self cells that lymphocytes can recognise:

A
  • Toxins
  • Tumour cells
  • Transplanted cells
  • Pathogens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are cells that belong to us called?

A

Self cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are cells that can trigger an immune response called?

A

Non-self cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are pathogens?

A

Any microorganism that causes disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Lymphocytes are _________ to one antigen.

A

Specific

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How are lymphocytes able to recognise antigens?

A

They have complementary receptors that bind to antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How many antigens can a lymphocyte recognise?

A

One (specific antigen)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When lymphocytes bind to an antigen, they trigger a _______ immune response.

A

Specific

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why are phagocytes non-specific?

A

Their receptors are complementary to the molecular patterns found on all pathogens.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

When a pathogen invades the body, the pathogen releases _______ that attract phagocytes towards it.

A

Chemicals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When a pathogen has released chemicals that attracts the phagocyte, the phagocyte moves towards it along a _____________.

A

Concentration gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

When the phagocyte reaches the pathogen, it binds to the pathogen via complementary _________.

A

Receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How to lysozymes aid in the digestion of a pathogen?

A

They speed up the hydrolysis reaction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Do phagocytes or lymphocytes carry out a nonspecific response against a pathogen?

A

Phagocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Where are B cells matured?

A

Bone marrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Where are T cells matured?

A

Thymus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the role of the disulphide bridge in forming the quaternary structure of an antibody?

A

Holds and stabilises the polypeptides together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the two types of white blood cells that lymphocytes can differentiate into?

A

T lymphocytes
B lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

If lymphocytes mature in the bone marrow, they are __-lymphocytes.

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

If lymphocytes mature in the thymus, they are __-lymphocytes.

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Which type of lymphocytes are involved in humoral immunity?

A

B-lymphocytes

32
Q

What is meant by humoral immunity?

A

Immunity involving the body’s humours, such as blood plasma or lymph.

33
Q

Humoural immunity involves the production of ________ antibodies.

A

Monoclonal

34
Q

Which type of lymphocytes are involved in cell-mediated immunity?

A

T-lymphocytes

35
Q

What do T lymphocytes deal with?

A

Cells that have antigens on their cell surface membranes only.

36
Q

What are the 4 types of T cells that T cells can differentiate into?

A
  • T memory cells
  • T helper cells
  • Cytotoxic T cells
  • Suppressor T cells
37
Q

Role of T-helper cells:

A
  • Releases cytokines (chemicals) to active B cells.
38
Q

Role of cytotoxic T cells:

A
  • Perforate cell walls.
  • Destroy infected cells
39
Q

How does cytotoxic T cells perforating cell walls cause the antigen to die?

A
  • Osmosis will occur.
  • Water will move into the antigen and cause it to burst.
40
Q

What is the role of B plasma cells?

A

Produce and secrete antibodies.

41
Q

What makes the non-specific immune response non-specific?

A

Response occurs immediately to infection and is carried out in the same way regardless of the pathogen.

42
Q

What stimulates the production and secretion of B cells.

A
  • When T helper cells produce cytokines
  • When antibody molecules on their CSM bind to a complementary antigen.
43
Q

Phagocytosis is an example of a _______ immune response.

A

Non-specific

44
Q

What do B-memory cells do when infection is rencountered?

A

Stimulate the rapid production of plasma B cells.

45
Q

Antibodies have a _____ structure.

A

Quaternary

46
Q

Antibodies have a quaternary structure made up of 4 _____ chains.

A

Polypeptide

47
Q

Describe 2 features of the 4 polypeptide chains in an antibody:

A
  • 2 dense chains, 2 light chains
  • Connected by disulfide bridges
48
Q

Antibodies are composed of a ____ region and an ________.

A
  • Variable
  • Antigen binding site
49
Q

Why is it called the variable region?

A

It is different in different antibodies.

50
Q

What makes an antibody specific to an antigen?

A

The antibody’s antigen-binding site is specific to the complementary antigen.

51
Q

The constant region is ___ ____ for all antibodies.

52
Q

What is the role of the constant region of an antibody?

A

Contains another binding site which allows the antibody to bind to immune cells.

53
Q

Name the 3 ways that antibodies work to destroy pathogens:

A

1) Agglutination
2) Neutralising toxins
3) Blocking access to human cells

54
Q

Explain agglutination as a way that antibodies work to destroy pathogens:

A
  • Antibodies will use their two binding sites to bind to two pathogens.
  • Clumps pathogens together.
  • Allows for phagocytes to efficiently engulf pathogens.
55
Q

Explain neutralising toxins as a way that antibodies work to destroy pathogens:

A
  • Antibodies will bind to toxins which neutralises them
  • Antibody-toxin complex can be destroyed by phagocytes.
56
Q

Explain blocking access to human cells as a way that antibodies work to destroy pathogens:

A
  • Antibodies will bind to antigens to prevent antigens from binding to human cells
57
Q

Immunity can either be ____ or _____.

A

Active or passive.

58
Q

What are the two types of active immunity?

A
  • Natural
  • Artificial
59
Q

What is natural active immunity?

A

When you become immune after catching a disease.

60
Q

What is artificial active immunity?

A

When you become immune after you’ve been given a vaccination containing an antigen.

61
Q

What is active immunity?

A

Immunity you get when your immune system makes its own antibodies after being stimulated by an antigen.

62
Q

What is passive immunity?

A

Immunity you get from being given antibodies produced by a different organism.

63
Q

What are the two types of passive immunity?

A
  • Natural
  • Artificial
64
Q

What is natural passive immunity?

A

When a baby becomes immune due to the antibodies it receives from its mother, through the placenta and breast milk.

65
Q

What is artificial passive immunity?

A

When you become immune after being injected with antibodies from someone else.

66
Q

A person has contracted tetanus. Explain how artificial passive immunity can help treat the illness:

A
  • Person can be injected with antibodies against the tetanus toxin, collected from blood donations.
67
Q

Name the 4 features of active immunity:

A
  • Requires exposure to an antigen
  • Protection develops over time
  • Memory cells are produced
  • Protection is long-term as the antibody is produced in response to the complementary antigen being present.
68
Q

Name the 4 features of passive immunity:

A
  • Doesn’t require exposure to an antigen
  • Protection is immediate
  • Memory cells are not produced
  • Protection is short-term as the given antibodies are broken down.
69
Q

What is the disadvantage of orally taking vaccines?

A
  • May be broken down by enzymes in the gut
  • Molecules may be too large to be absorbed into the blood.
70
Q

What is antigenic variation?

A

When pathogens change their surface antigens.

71
Q

What is the impact of antigenic varitation?

A

Means memory cells will not recognise the antigen and the primary response will occur again.

72
Q

What are monoclonal antibodies?

A

Antibodies produced from a single group of genetically identical plasma B cells.

73
Q

What does the ELISA test stand for?

A

Enzyme-linked immunosorbent assay

74
Q

What does the direct ELISA use?

A

A single antibody that is complementary to the antigen that is being tested for.

75
Q

What are the two types of ELISA test?

A
  • Direct
  • Indirect
76
Q

What does the indirect ELISA test use?

A

Two different antibodies.

77
Q

Define an antigen:

A

A protein found on the cell surface membrane which triggers an immune response.

Biology Paper 1 (32 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions