Module 4, Section 1: Antibodies and the immune system.

Describe the structure of an antibody.

2 variable regions attached to a constant region, which are attached via the disulfide bridge. The hinge region allows the antibody to move.

What mechanisms do antibodies use to neutralise pathogens?

1. Agglutination. Due to having two variable regions, the antibodies can clump the pathogens together. Phagocytes then engulf this clump.

2. Neutralising toxins. Antitoxins can bind to the toxins released by bacterial cells, minimising their effect on the body. The antibody-antitoxin complex is then phagocytosed.

3. Preventing pathogens from binding. Antibodies can bind to all available antigens, meaning the pathogen cannot bind to the host cell.

What’s the difference between the primary and secondary immune response?

Primary takes a while to produce the necessary antibodies to fight the disease. Also produces memory cells that remember how to fight the disease.

The secondary response is far faster, because of memory cells.

Why is continua exposure to pathogens required?

Because memory cells have limited life spans, so more copies of b and t lymphocytes are needed.

What are the two types of active immunity.

1. natural. immunity that is gained after catching a disease.

2. artificial. immunity that us gained from outside intervention, like a vaccine.

What are the two types of passive immunity.

1. natural. like when a fetus gains immunity from its mothers milk, in the form of antibodies.

2. artificial. like when being injected with antibodies.

What is herd immunity and how does it limit the spread of disease?

Where most of the population is vaccinated against a specific pathogen, and thus the pathogen has no people to transmit to. Chains of transmission are broken.

What are different ways to fight diseases?

Antibiotics. They stop bacteria from being able to replicate, thus averting further harm to the patient.

Why is maintaining biodiversity important for the future of medicine?

There could be compounds in animals and plants that could prove useful, and they need to live long enough for us to have a chance to study them.

What is personalised medicine?

Medicine that is tailored to a patients indvidual geonme, thus analysing what medication they might respond best to.