Unit 4 - Specific immune response

Question 1

What are antibodies?

Answer 1

Y-shaped glycoproteins made by B cells of the immune system in response to the presence of an antigen

Question 2

What is a specific immune response?

Answer 2

The immune system ‘remembers’ an antigen after an initial response leading to an enhanced response to subsequent encounters

Question 3

What shape are antibodies?

Answer 3

Y-shaped

Question 4

Where do T-cells mature?

Answer 4

Thymus gland

Question 5

Where do B-cells mature?

Answer 5

Bone marrow

Question 6

What is the function of B plasma cells?

Answer 6

To produce antibodies

Question 7

How does the sequence of amino acids affect an antibody?

Answer 7

The sequence of amino acids determines the shape of the variable region (sequence of amino acids) and so which antigen is detected

Question 8

How many polypeptide chains does an antibody contain?

Answer 8

4

Question 9

What type of molecule is an antibody?

Answer 9

Protein

Question 10

What is the relationship between the two light chains of antibodies?

Answer 10

They are identical

Question 11

What is the relationship between the two heavy chains of antibodies?

Answer 11

They are identical

Question 12

What sort of protein are antibodies?

Answer 12

Globular

Question 13

How many binding sites are there on an antibody?

Where are they?

Answer 13

3
Two antigen binding sites
One receptor site that allows the body to recognise the antibody as self

Question 14

How are all antibodies in the body similar?

Answer 14

They share the same common region

Question 15

What type of bonding occurs between the heavy and light strands in antibodies?

Answer 15

Disulfide

Question 16

How are the heavy strands attached in antibodies?

Answer 16

Disulfide bonds

Question 17

How many light strands are in an antibody?

Answer 17

2

Question 18

How many heavy strands are in an antibody?

Answer 18

2

Question 19

What is the relationship between the variable region and the antigen?

Answer 19

They have complementary shapes

Question 20

What allows for sulfide bonding?

Answer 20

The amino acid cysteine

Question 21

Why do antibodies have a hinge?

Answer 21

Allows antibodies to flex slightly and accommodate differently sized antigens

Question 22

What is the difference between the light and heavy chains of an antibody?

Answer 22

The light chains are much shorter than the heavy chains

Question 23

How many amino acids form a binding site?

Answer 23

110

Question 24

What is formed when an antibody binds to an antigen?

Answer 24

An antigen-antibody complex

Question 25

How do antibodies defend the body? (4 reasons)

Answer 25

• Act as opsonins so the antigen is ‘tagged’ and easily engulfed
• Act as antitoxins, binding to toxins produced by pathogens to render them harmless
• Cause agglutination (clumping together) of pathogens which have antigen-antibody complexes, preventing them from spreading through the body and makes it easier for phagocytes to engulf several pathogens at once
• Prevents pathogens from effectively invading a host

Question 26

Name the 4 types of T cells

Answer 26

• Killer T cells
• Helper T cells
• Memory T cells
• Regulator T cells

Question 27

Name the 3 types of B cells

Answer 27

• B Plasma cells
• B effector cells
• B memory cells