Antibodies

Question 1

How many proteins make up an antibody?

Answer 1

4

Question 2

What is the variable region on an antibody?

Answer 2

the area on an antibody that contains the antigen binding site. They are different on each antibody, this is caused by the difference in the primary structure of the protein.

Question 3

What is the constant region of an antibody?

Answer 3

an area of the antibody that stays the same on every antibody

Question 4

What is agglutination?

Answer 4

When antibodies bond to more than one pathogen causing them to clump together

Question 5

Why does agglutination aid the immune response to a pathogen?

Answer 5

It leads to an increased rate in phagocytosis, as more than one pathogen can be engulfed and destroyed at the same time. (also increases the concentration of chemicals, attracting more phagocytes)

Question 6

Why are antibodies specific to one antigen?

Answer 6

• the variable region of an antibody contains the antigen binding site
• the 3° structure of this protein is specific and is complementary to one antigen
• this is caused by the different 1° structures that result in the variable region having a varied, specific shape
• as the shape of the antigen binding site is specific is can only form antibody-antigen complexes with the antigens on a specific pathogen

Question 7

What is an antibody?

Answer 7

a protein specific to an antigen
that is produced by B cells/plasma cells

Question 8

What is a Monoclonal antibodies?

Answer 8

a single type of anti-body that can be isolated and cloned

Question 9

How does an ELISA test test for the presence of antigens?

Answer 9

• sample is attached to slide, excess is washed off
• complementary antibody to the antigen being tested for is added, unbound antibodies are washed off
• a 2nd complementary antibody is added, it is complementary to the firstand has an enzyme attached Unbound antibodies are washed off
• substrate is added, it will produce a coloured product in the presence of an enzyme
  colour change = antigen
  no colour change = no antigen

Question 10

Describe the process of direct monoclonal antibody therapy to treat cancer

Answer 10

• MAB designed with a binding site complementary to the antigen on the cancer
• once bound, antibodies stop chemicals binding to the cell that cause division
• cancer cells stop growing

Question 11

What bond occurs between 2 cysteine amino acids?

Answer 11

disulfide bridges

Question 12

Why do antibodies bind to a specific substrate?

Answer 12

antibodies have a specific tertiary structure which is complementary to a specific substrate