Antibodies - 18/12/23 Flashcards
In the humoral response what do plasma cells produce?
Antibodies
What are antibodies made of?
4 polypeptide chains
What protein structure does antibodies have?
Quarternary structure
Describe the structure of Antibodies.
[5]
- Two large and two small chains (heavy/light)
- Two antigen binding sites
- Variable region
- Constant region
- Disulfide bridges
What shape does the 4 polypeptides chains in an antibody form?
Y shape
What does the Variable Region in an antibody do?
- It makes the antibody specific
- Forms antigen binding sites
What is the protein structure of variable region in an antibody?
Unique tertiary structure
How can the antibody bind to specific antigens?
[2]
- Because the antigen-binding sites (variable region)
- is complementary to only one specific antigen
When antibody attaches to antigen what does it form?
Antigen-antibody complex
How does Antibody-Antigen Complex form?
[2]
- Antibodies randomly collide with non-self antigens on a foreign cell
- It will bind if antigens have complementary shape
What is Agglutination?
[2]
- The antibody has two-antigen binding sites so they can bind to more than one pathogens
- This results in pathogens being clumped together
What can antibodies do after Agglutination?
[2]
- Neutralise pathogen
- Attract phagocytes to engulf and destroy cells
What does B-Cells have on surface? What is it specific to?
Antibodies that’s specific to one specific antigen
Is humoral response specific or non-specific?
Specific
What stimulates the specific humoral response?
When receptor binds to complementary antigen of non-self pathogen
What do B-Cells have on surface membrane?
Receptor antibodies
When the receptors are released form B-cells, what do they become?
Antibodies
What happens in Humoral Response?
- Pathogens invade the body
- Non-specific response: macrophage (phagocytosis)
- Pathogen antigens embed in cell membrane of macrophage
- This activates B-cells with complementary antibodies on its membrane (aided by Helper T Cells)
- Activated B cells produce many clones by mitosis
- Some clones become Plasma cells or Memory B Cells
- Plasma cells secrete specific antibody (monclonal)
- Antibody-Antigen complex formed
- This Inactivates Pathogens or Stimulates Phagocytosis
- The memory B cells continue to secrete antibodies for years, reproduce rapidly to produce lots of plasma cells if same pathogen entered
What is the first Non-Specific response in Humoral response?
Macrophage (phagocytosis)
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How is the B-cells activated in Humoral response?
Pathogen antigens embed in cell membrane of macrophage
What are the two types of cells produced when activated B cells produce clones?
- Plasma cells
- Memory B Cells
What do Plasma Cells secrete in humoral response?
Monoclonal antibody
When an antibody-antigen complex is formed in humoral response, what two things can this do?
- Inactivate pathogen
- Stimulate phagocytosis
What do Memory B Cells do in humoral response?
Continue to secrete antibody for years, repoduce rapidly to produce lots of plasma cells if same pathogens are encountered
