RAW (2) ANTIBODIES

Question 1

Define an antigen

Answer 1

• A molecule that can stimulate the production of an antibody
• Large and complex molecules eg protein/glycoprotein
• Specific shape
• Associated with organisms surface (eg cell surface membrane/cell wall)
OR
Secreted/excreted by the organism

Question 2

Define antibodies

Answer 2

Antibodies:
• Known as IMMUNOGLOBULINS
• Specific complementary shapes to specific antigens
• Produced in lymph nodes by B-lymphocytes —> travel in lymph to blood stream —>circulated around the body
• Several forms
○ IgG most common (75% in humans)

Question 3

Label an antibody

Answer 3

Add photo

Question 4

What are some antibody actions

Answer 4

Antibody actions:
• Antibodies act in several diff ways:
○ Agglutination (sticking pathogens together)
§ Prevents spread through tissues & cell entry
§ Phagocytes respond more aggressively to bacteria bound to antigens
○ Neutralisation of bacterial toxins
§ If an antibody binds to an antigen which has a complementary host cell, the pathogen is harmless
□ (it cannot attach to host cell)
○ Lysis
§ As antibodies bind, they may cause release of proteins in blood
□ They digest bacterial wall
® Causes bacterial immobilisation (paralysis of flagella)

Question 5

Define the primary immune response

Answer 5

Primary immune response:
• Slow
○ Time lag from infection to production
§ Complementary B and T lymphocytes contacting antibodies
§ Mitosis
§ Antibody production
• Low antibody production
• Does not lead to immunity

Question 6

Define the secondary immune response

Answer 6

Secondary immune response:
• Fast
○ Shorter time lag from infection to production
§ Faster production
§ Antibody concentration stays higher for longer
• High antibody production
• Long-lasting immunity

Question 7

Draw the antibody content against time graph

Answer 7

Add photo