5.5 Antibodies

Question 1

What are antibodies?

Answer 1

Proteins with specific binding sites synthesised by B cells.

Question 2

Why is a massive variety of antibodies possible?

Answer 2

Because they are made of proteins, molecules that occur in an almost infinite number of forms.

Question 3

How many polypeptide chains are antibodies made out of?

Answer 3

4

Question 4

What type of chains are the 4 polypeptide chains sorted into?

Answer 4

The long pair are called heavy chains, while the shorter pair are called light chains.

Question 5

Each antibody has a specific binding site that fits very precisely onto a specific antigen to form a …..?

Answer 5

antigen-antibody complex

Question 6

Why is the binding site on an antibody known as the variable region?

Answer 6

Because the binding site is different on different antibodies.

Question 7

What does a binding site consist of?

Answer 7

A sequence of amino acids that form a specific 3-D shape that binds directly o a specific antigen.

Question 8

What do you call the rest of the antibody?

Answer 8

The constant region

Question 9

What are the 2 ways antibodies assist in destruction of antigens/bacterial cell?

Answer 9

1. they cause agglutination of bacterial cells. In this way clumps of bacterial cells re formed, making it easier for phagocytes to locate them as they are less spread-out within the body.

Question 10

What are the 2 ways antibodies assist in destruction of antigens/bacterial cell?

Answer 10

1. they cause agglutination of bacterial cells. In this way clumps of bacterial cells re formed, making it easier for phagocytes to locate them as they are less spread-out within the body.
2. they then serve as markers that stimulate phagocytes to engulf the bacterial cells to which they are attached.

Question 11

Why is agglutination possible?

Answer 11

Because each antibody has 2 antigen binding sites.