4.1.7- Antibodies

Question 1

What are anti toxins?

Answer 1

Antibodies that render toxins harmless.

Question 2

What are opsonins?

Answer 2

A type of antibody that attaches to the antigen on a pathogen, making it easier for the phagocyte to bind.

Question 3

Explain what shit primary immune response is.

Answer 3

The initial response that is caused by first infection of a pathogen.

Question 4

What is the secondary immune response?

Answer 4

A more rapid and vigorous response that is caused by a second or subsequent infection of the same pathogen.

Question 5

Antigens are molecules that can…

Answer 5

Stimulate an immune response.

Question 6

What are most antigens?

Answer 6

Either proteins or glycoproteins in the plasma membrane of a pathogen.

Question 7

Antibodies are _________ to the pathogen.

Answer 7

Specific.

Question 8

How are antigens produced, simply?

Answer 8

The foreign antigen is detected by a he immune system and will stimulate the production of antibodies.

Question 9

antibodies are __________.

Answer 9

Immunoglobulins.

Question 10

Explain what an immunoglobulin (an antibody) is.

Answer 10

Complex proteins that are produced by the plasma cells in the immune system.

Question 11

What shape are antibodies?

Answer 11

Y shaped.

Question 12

Antibodies consist of ________ chains of polypeptides.

Answer 12

Four.

Question 13

In an antibody, there are two _______ polypeptide chains and two _______ chains.

Answer 13

Light.

Heavy.

Question 14

List the four main features of an antibody that help its function.

Answer 14

Hinge region
Disclose bridges
Constant region
Variable region

Question 15

Explain how disulphides bridges in the antibody help its function.

Answer 15

Holds the chains of polypeptides together stably and keeps the shape of the molecule preserved.

Question 16

Explain how the constant region of an antibody helps it for ta function.

Answer 16

It is the sand for all antibodies and allows binding to receipts inimitable system cells (eg phagocytes) for the easy binding of these cells.

Question 17

Explain what the hinge region of an antibody is and how it helps for its function.

Answer 17

It allows flexibility of the molecule so the molecule can grip into more than one antigen- improving the antibodies efficiency.

Question 18

Explain how the variable region of an antibody helps for its function.

Answer 18

This region forms the antigen binding site and the shape is complementary and specific to the antigen of the pathogen it defends against. It differs between antibodies in terms of shape.

Question 19

Antigens bind to the surface of an antibody to form a what?

Answer 19

Antigen- Antibody Complex.

Question 20

The structure of an antibody directly depends on what?

Answer 20

The sequence of amine acids in the polypeptide chain– the primary structure of the protein.

Question 21

How do antibodies reproduce?

Answer 21

Protein synthesis- translation and transcription

Question 22

List the three ways an antibody can work in defence against a pathogen.

Answer 22

• Agglutination of pathogens
• Neutralising toxins
• Opsonin action
• Preventing the pathogen from binding to human cells.

Question 23

Explain how opsonins (a type of antibody) work to defend against a pathogen.

Answer 23

They attach to the antigen on the pathogen and act as the binging site for phagocytes.

Question 24

Explain how an antibody can work by neutralising a pathogen.

Answer 24

The antibodies (called antitoxins in this case) can being to toxins produced by pathogens- neutralising them and preventing them from binding to human cells. The toxin has a specific shape and the toxin- antibody complex is also phagocytosed.

Question 25

Explain how an antibody can work by ‘preventing the pathogen from binding to human cells’.

Answer 25

An antibody can block the cell surface receptors a pathogen needs to bind to host cells when it binds to the pathogen’s antigen- stopping it attacking to or infecting a host cell.

Question 26

Explain how a pathogen can be prevented from exerting its effects on a cell by antibody ‘agglutinating’.

Answer 26

The agglutinins have two binding sites so bind to two antigens at once and the pathogens become clumped due to the ‘cross linking’ of them.

Question 27

Explain two advantages of pathogens being agglutinate do by agglutinins.

Answer 27

• the agglutinate do proteins are readily engulfed by pathogens.
• the agglutinated pathogens are physically impeded from carrying out some functions- eg entering host cells

Question 28

What makes a person immune from a disease?

Answer 28

The presence of B and T memory cells in the blood that will recognise the specific antigens of the pathogen when the pathogen enters the cell and swings the immune system into action.

Question 29

Explain how immunity is provided for a person the second time they get infected by a pathogen.

Answer 29

B+T lymphocytes are produced after first infection and B memory cells divide into Plasma cells after the second infection that procure the right antibodies and T memory divide into the correct T lymphocytes to kill the virus- making the response quicker and stronger.

Question 30

Why is the primary response slower than the secondary response?

Answer 30

There aren’t many B lymphocytes present that an differentiate into plasma cells to produce the antibodies needed.

Question 31

How is the primary response activated?

Answer 31

The antigens on the surface of the pathogen that’s entered the body is detected by the immune system that triggers the immune system.

Question 32

Explain reasons why the secondary response is faster than the primary one.

Answer 32

Clonal selection happens faster due to the presence of these memory cells and B lymph’s differentiate into plasma cells quicker to release antibodies to attack the pathogen faster.

Question 33

In what type of response do you not experience symptoms when infected with the pathogen?

Answer 33

The secondary response- due to the speed of it.

Question 34

Describe what cells are activated in the secondary and primary immune responses initially.

Answer 34

Primary; B and T lymphocytes.

Secondary; memory cells.

Question 35

What are agglutins?

Answer 35

Antibodies that cause pathogens to stick together.