KEGS Biology Blog

Friday 18th January Section 4
January 18, 2013, 10:28 pm
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15 Comments so far
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Antibodies have a specific shape that is complementary to a particular antigen.

Comment by candicetam

Antibodies are proteins which have a shape complementary to specific antigens. They attach themselves to those antigens and destroy it.

Comment by yuansun

Antibodies are protein molecules that detect antigens and neutralize them and render them harmless.

Comment by hinalipatel

Antibodies are large proteins that have a specific shape to a complementary to a specific antigen.

Comment by helenquah

Antibodies are substances that are produced by the body in response to invasion by a foreign pathogens

Comment by nisithadissanayake

Structure of an antibody:
An antibody molecule is Y-shaped
It has 4 polypeptide chains held together by disulfide bridges
It has a constant region, which enables the antibody to attach to phagocyticeclls and helps in the process of phagocytosis.
It has a variable region, which differes between each antibody, and depends on its amino acid sequence. It ensures that the antibody can only attach to the correct antigen, by complementary shaping.
It has a hinge region, which allows flexibility, it allows the Y shape to move further apart in order to allow attachment to more than one antigen.

Comment by spencerfinch

Definition of an antibody (from the textbook so suitable for the exam): A protein molecule that can identify and neutralise antigens.

Specificity: An antibody is specific to a particular antigen because of the shape of the variable region. Each type of antibody has a differently shaped variable region.

Comment by danialnaqvi

The first time an anitgen is detected production of the coresponding antibody (immune response) takes a few days before it is effective.
Once the pathogens are destroyed the number of antibodies drops rapidly.
However if the same infection occurs anitbody production will be much quicker and will start sooner (secondary Immune Response)

Comment by bensubhani

Antigens are classically defined as any foreign substance that elicits an immune response. They are also called immunogens. The specific region on an antigen that an antibody recognizes and binds to is called the epitope, or antigenic determinant.

Comment by hannahgooch – this website is quite useful but I’m not sure how much of it we need to know because its not exam specific or anything

Comment by hannahgooch

B lymphocytes (B-cells) develop into B-plasma cells and B-memory cells. When the B-cells have gone through clonal selection to identify the correct complimentary protein for the pathogens antigen, they differentiate and through mitosis expand in numbers the B plasma cells then float around in the blood releasing the anti-bodies specific to the particular antigen being faced. B memory cells will remember the variable shape of the antibody being released so if a secondary infection occurs anti-bodies can be released almost immediately.

Comment by jaimieclifford

Antibodies, also called immunoglobulins, are large Y-shaped proteins which function to identify and help remove foreign antigens or targets such as viruses and bacteria. Every different antibody recognizes a specific foreign antigen. This is because the two tips of its “Y” are specific to each antigen, allowing different antibodies to bind to different foreign antigens.

Antibodies are produced by the immune system in response to the presence of an antigen. Antigens are large molecules, usually proteins, on the surface of cells, viruses, fungi, bacteria, and some non-living substances such as toxins, chemicals, and foreign particles. Any substance capable of triggering an immune response is called an antigen

Comment by halima101

Antibodies in mammals are grouped into 5 kinds known as isotypes. Each of these 5 isotypes perform different roles and direct the immune response action for each foreign object they encounter

Comment by phillipmarriage

Isotype or class switching is a biological process which happens after activation of the B cell, which allows the cell to produce different classes of antibody (IgA, IgE, or IgG). Class switching is triggered by cytokines; the isotype generated depends on which cytokines are present in the B cell environment.

Comment by alexgurton

Antibodies function in the body as a double-edged sword. With one edge they protect the body from microbes and with the other they can cause severe allergic reactions to relatively harmless proteins and other molecules present in food, environment, medicines etc.

IgE is the most important mediator of hypersensitivity or allergic reactions. When it binds to multivalent antigens there is activation of the mast cell, which releases chemical mediators stored in granules and capable of mediating local inflammatory reactions. This is called mast cell degranulation.

Comment by matthewbesley

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