Exam (elaborations)
CMB 2004 IMMUNITY EXAM QUESTIONS AND ANSWERS
- Course
- Institution
CMB 2004 IMMUNITY EXAM QUESTIONS AND ANSWERS...
[Show more]
Content preview
CMB 2004 IMMUNITY EXAM QUESTIONS ANDANSWERS
What must an effective immune response do? (4 things) - ANSWER Be able to
recognise and respond to invading pathogen
Not over-react to to benign or self
Be able to direct different effector mechanisms against different pathogens
Links innate and adaptive responses
What is adaptive immunity? (3 details) - ANSWER It is induced by exposure to a
PARTICULAR infection, it has a high degree of specificity.
It exhibits memory
What is the clonal selection theory? Why? - ANSWER It states that each
lymphocyte has membrane-bound immunoglobulin receptors specific for a
particular antigen and after the receptor is engaged, proliferation of the cell occurs
such that a clone of antibody-producing cells is produced.
This is because there's a low frequency of cells specific for any antigen, more
receptors than cells.
Describe the level of antibody production in the primary and secondary immune
response? - ANSWER When first exposed to antigen, low antibody production
(innate response, non specific)
Adaptive starts to with increased Ig production.
Decrease in Ig means the immune response has been successful.
With a secondary infection the lag phase would be quicker, so more antibodies are
produced quickly.
Where's the BCR expressed? - ANSWER by B lymphocytes (The membrane form
,of Ig), secreted when the B cell is activated)`
What does the BCR bind? - ANSWER Free antigen
Where's the TCR expressed? - ANSWER On T lymphocytes, membrane form only
What does the TCR bind? - ANSWER Recognizes peptide fragments (processed
antigen)
bound to MHC
What's the immunoglobulin superfamily? - ANSWER a large group of cell surface
and soluble proteins that are involved in the recognition, binding, or adhesion
processes of cells. Including Antibodies T cell receptors, MHC molecules
What are the two main functions of antibodies? - ANSWER To activate
complement- for oposonisation, classical pathway activation and MAC
Activation of effector cells- Cells that express FcR (the receptor that binds to the
FC region of the antibody)
Describe the structure of an antibody - ANSWER Formed via 4 polypeptides
C terminus at the constant region, N terminus at the variable regions.
Has different domains, Hc identical as are Lc
held by both covalent and non covalent bonds
What region of an antibody is the antigen binding site made up of? - ANSWER The
variable regions of one heavy and one light chain
What is the constant region of an antibody? - ANSWER The region which is the
same in any antibody. Responsible with interacting with molecules such as FcR and
cells of the innate system for antibody effector functions
What's the structure of a light chain of the antibody? - ANSWER It has a lamda or
kappa regions
What are Fc regions? - ANSWER They are Ch regions which interact with effector
cells via FcR and complement
What are the 5 classes of antibodies? - ANSWER IgM---- largest antibody, first to
,appear, pentamer (10 binding sites)
IgA---- mucosal immunity, including tears and saliva
IgD--- coexpression with IgM, Secreted in blood serum
IgG---Most common, crosses placenta so protects the fetus, causes opsonisation
IgE--- immunity to helminths, least abundant, allergies
What are domains in an antibody? - ANSWER The domains are highly conserved
between bits of the immune system,
The heavy chain has 4 or 5 whilst the light has 2
Composed of 2 beta sheets held via disulphide bridges
each 110 aa in length
What is the MHC? - ANSWER Major histocompatibility complex
A set of genes which encode cell surface molecules, bind peptide fragments and
display then on the surface for recognition.
How do antibodies and antigen interact? - ANSWER Via the binding site, variable
regions are specific to a given antibody..
possess hypervariable regions, variable regions within variable regions ( 3 in Hv
and 3 in Lv) HV1-3
6 hv loops make up the binding site
What are complementary determining regions? - ANSWER CDRs are the same as
hypervariable regions (CDR1-3)
Antigen binds to amino acids in CDRs (affected by the size and shape)
What are the two types of antigen recognition? - ANSWER Linear (continuous)
epitope: 3 single amino acids/ 3 regions of antigen , sequential
Non linear/discontinuous epitope: conformational
What is an epitope? - ANSWER The region of an antigen that the antibody
recognises
, Describe the structure of the TCR? - ANSWER Recognises short peptide
fragments, bound to MHC
It's a heterodimer of alpha and beta
each chain possesses a V and C region
4 domains are Ig like
V domains interact with antigen
each chain contributes 3 CDRs to antigen binding
What's the difference in structure between MHC class I & II? - ANSWER Class I:
1 TM domain (expressed on ALL nucleated cells)
Class II: 2 TM domains (on only APC)
What's the MHC in humans? - ANSWER Human Leukacytes Antigen (HLAs):
What are class I HLAs? - ANSWER HLA-A, HLA-B and HLA-C
They are heterodimers
the alpha chain changes but the beta 2 chain remains the same (microglobulin,
12kD)
Alpha 1 & 2= peptide binding site
Alpha 3 and beta 2 are Ig like
What are class II HLAs? - ANSWER HLA-DP, HLA-DQ and HLA-DR
they are heterodimers where the alpha and beta chains are similar in size as they are
both transmembrane
encoded by seperate genes
alpha 2 and beta 2= Ig like
alpha 1 and beta 1= form peptide binding site
What type of peptides do different MHC bind? - ANSWER Class I: Short peptides,
snaps around
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller luzlinkuz. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $12.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
84146 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now