CIE 11.2 Structure and Function of Antibodies (A-level biology + Osmosis)

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Questions and Answers

What is the main function of the variable region of an antibody?

To allow for the clumping of multiple pathogens

To serve as a binding site for specific antigens (correct)

To provide stability to the antibody structure

To facilitate the neutralization of toxins

Which statement best describes the hinge regions of antibodies?

They consist of identical amino acid sequences across all antibodies

They enable flexibility to allow binding with multiple antigens (correct)

They are rigid and do not allow movement between chains

They contain the antigen binding site

How do antibodies contribute to agglutination?

By neutralizing the toxins produced by bacteria

By binding to multiple pathogens and clumping them together (correct)

By marking pathogens for destruction without directly binding

By directly destroying pathogens via enzymatic action

What role do antibodies play in neutralizing viral infections?

They block viral attachment proteins from binding to host cells Signup and view all the answers

Which component of antibodies is constant across all antibody types?

The constant region Signup and view all the answers

What is a unique structural feature of antibodies that aids in their function?

They contain both heavy and light chains Signup and view all the answers

In what manner can antibodies mark pathogens for immune response?

By providing a beacon for phagocytes and lymphocytes Signup and view all the answers

What happens when antibodies bind to endotoxins produced by pathogens?

They neutralize the endotoxins and protect the host Signup and view all the answers

What is the primary characteristic that distinguishes monoclonal antibodies from polyclonal antibodies?

Monoclonal antibodies have a binding site that recognizes specific and unique antigenic sequences. Signup and view all the answers

Which of the following best describes the hybridoma method used in the production of monoclonal antibodies?

It utilizes the fusion of splenic and cancerous cells to continuously produce antibodies. Signup and view all the answers

What is one key function of monoclonal antibodies in cancer treatment?

They recognize and bind to specific tumor markers on cancer cells. Signup and view all the answers

Which statement accurately reflects the application of monoclonal antibodies in medical diagnosis?

They help in detecting specific antigens in blood or tissue samples. Signup and view all the answers

What role does the spleen play in the production of monoclonal antibodies?

It produces B cells that are essential for antibody production. Signup and view all the answers

Which of the following correctly describes the binding ability of polyclonal antibodies?

They have a diverse binding site allowing recognition of multiple variations of the same antigen. Signup and view all the answers

How are monoclonal antibodies utilized in treating poisoning?

They neutralize specific poisons present in the bloodstream. Signup and view all the answers

Which statement about the mass production of monoclonal antibodies is incorrect?

The production method is limited to infections acquired from humans. Signup and view all the answers

Study Notes

Overview of Antibodies

Antibodies are glycoproteins that recognize specific antigens.
Their structure, a Y-shape consisting of four polypeptide chains (two heavy and two light), determines their function and specificity.
Each antibody has a constant region for binding with phagocytes and a unique variable region that serves as the antigen binding site, analogous to an enzyme's active site.
Flexible hinge regions allow for movement, enabling antibodies to bind to multiple antigens.

Antibody Functions

Neutralisation:
- Antibodies neutralize pathogens by binding to and neutralizing harmful endotoxins produced by bacteria.
- They can also bind to viral attachment proteins, preventing viral infection of host cells.
Agglutination:
- Antibodies can clump pathogens together, making it easier for phagocytes to engulf multiple pathogens simultaneously.
Marking:
- Bound antibodies act as markers for immunological cells, recruiting phagocytes and lymphocytes to the pathogen.
Lysis:
- Enzymes can attach to antibodies linked to pathogens. These enzymes catalyze reactions that break down associated bacteria.

Monoclonal vs. Polyclonal Antibodies

Monoclonal Antibodies: Highly specific, recognizing only unique antigenic sequences.
Polyclonal Antibodies: Diverse binding sites that recognize different variations of a specific antigen, including variations among species or mutants.

Functions of Monoclonal Antibodies

Treating Poisoning: Neutralize various poisons in patients.
Cancer Treatment: Target tumor markers on cancer cells, attracting T-cells and possibly shipping anti-cancer drugs.
Medical Diagnosis: Identify specific antigens in blood or tissue samples, such as using monoclonal antibodies for pregnancy testing by detecting hCG in urine.

Producing Monoclonal Antibodies

The hybridoma method is used for mass production of monoclonal antibodies:
- A mouse is injected with an antigen, stimulating an immune response and antibody production.
- Spleen cells, rich in B cells for antibody production, are extracted from the mouse.
- These spleen cells are fused with myeloma cells (cancerous white blood cells), creating hybridoma cells that can divide indefinitely and produce monoclonal antibodies.
- Hybridomas are cultured, and the produced monoclonal antibodies are harvested for use.

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Description

This quiz provides an overview of antibodies, focusing on their structure, function, and specificity. You will learn how antibodies recognize specific antigens and the importance of their Y-shaped structure. Test your knowledge on these essential components of the immune system.