Immunoglobulins Flashcards Preview

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Flashcards in Immunoglobulins Deck (13):
1

What are immunoglobulins?

They are glycoproteins (sugar proteins)

2

What are immunoglobulins used for?

Different functions
- Opsonize- immunoglobulins coat antigen (say bacteria) & mark it & get it phagocytized
- Neutralize- Can coat pathogen with antibodies & make it ineffective by taking up binding sites
- Activation of complement system- Antibody binds and activates complement system which introduces MAC which makes pores which destroys pathogen

3

What do B cells secrete? What type of response?

- Immunoglobulins (Ig's), they create immunoglobulins
- They make a lot of immunoglobulins
- But only one antigen type, one type of antibody specific to one antigen
- They have humoral response

4

Structure of immunoglobulin/antibody

- 2 Heavy regions & 2 light regions
- held together by disulfide bonds
- Fab region (top half) binds antigens (specific to antigen). Determines antigen binding
- Fc region (bottom half) binds to receptors on cells

5

Immediate response, acute infection

IgM

6

Delayed response

IgG

7

If we take blood sample from a patient and find IgG what does that mean?

It means they have been infected with the bug for awhile because the body takes awhile

8

Function of IgG

- It does everything
- Main Ig in blood
- Activate complement system, create membrane attack complex MAC.
- Kill it
- Opsonize
- Neutralize

9

What does IgM do?

- Immediate response
- Important structure (pentomeric) Fc region bound together in middle, Fab portions sticking out so it can bind many antigens (5)
- Great for agglutination because its huge
- Bind or fix complement
- Found on B cell surface

10

IgA points

- Mucous membrane
- Gets passed from mother to baby through breast milk, baby receives passive immunity
It coats:
- Saliva
- Gastric wall
- Intestinal mucosa
Anywhere where there is mucous
- Structure: diameric & dimer
- Does not fix complement (activate membrane attack complex)

11

What do the IgM & IgG have in common?

They both activate the complement system whereas the others do not

12

IgD

- Found in monomeric state
- Found on B-cell surface
- Does not fix complement

13

IgE

- Helminth (worm infection)
- Binds to helminth coat, this will signal to the eosinophils to attach to helminth & they will release contents which will kill the helminth
- Associated with mast cells & basophils
- Allergic allergies