B4

A bacteria that causes diseases.

A virulent pathogen called EBOV.

Ebola is spread by someone who has become sickened by the virus. From there, the actual transmission occurs through contact with bodily fluids. Those bodily fluids include sweat, blood and feces. The virus can also spread through bodily fluids after the infected victim dies.

Malaria is caused by organisms of the genus Plasmodium, a parasite that infects human red blood cells. There are 3 different eukaryotic organisms from the genus Plasmodium that are responsible for the contraction of malaria.

Viral replication is the formation of biological viruses during the infection process in the target host cells. Viruses must first get into the cell before viral replication can occur. From the perspective of the virus, the purpose of viral replication is to allow production and survival of its kind.

An infectious bacterial disease characterized by the growth of nodules (tubercles) in the tissues, especially the lungs.

• Coughing up blood
• Fever
• Chest pain
• Chills
• Weight loss
• Night sweats
• Long-term cough
• No appetite
• Fatigue

A fungus thats causes disease.

They don't have a cellular structure.

• Your age - risk increases as you get older.
• Your family history - your risk may increase if close blood relatives experienced early heart disease.

Cardiovascular disease symptoms may be different for men and women. For instance, men are more likely to have chest pain; women are more likely to have symptoms such as shortness of breath, nausea and extreme fatigue.

Can be passed from person to person e.g. colds.

Can't be passed from person to person e.g. mental health.

The reaction of the cells and fluids of the body to the presence of a substance which is not recognized as a constituent of the body itself.

• Skin
• Mucus membranes
• External barriers
• Immune system

• Combined acidity
• Protein digesting enzymes

The mucus membanes because it's a thinner layer of cells.

• Fever
• Inflamatory response
• Immune response

Cilia movement carries the mucus in the back of your throat away because they are long so can reach the mucus. But if you smoke, the cilia gets shorter and can't reach the mucus. This is bad because the mucus is carrying all the bad stuff in a ciggarette. The cilia also helps the pathogens get coughed up or swallowed.

• DNA replication
• Metabolition (enzyme activity)
• Protein production (ribosomes)

Prevents the cell from building a cell wall.

Penicillin V : Sore throats

Amoxicillin : Chest infections

Flucloxacillin : Skin infections

They kill the natural flora of the gut. This can cause diarrhoea.

BACTERIOSTATIC : Viruses incorporate themselves into a host cell in order to multiply.

BACTERICIDAL : Cannot kill viruses.

Viruses don't have a cell wall.

• Sneezing
• Coughing
• Kissing
• Contact
• Breathing
• Food
• Water
• Sex

Lymphocytes.

People can be immunised against a pathogen through vaccination. Different vaccines are needed for different pathogens.

Vaccination involves putting a small amount of an inactive form of a pathogen, or dead pathogen, into the body. Vaccines can contain:

• live pathogens treated to make them harmless
• harmless fragments of the pathogen
• toxins produced by pathogens
• dead pathogens

These all act as antigens. When injected into the body, they stimulate white blood cells to produce antibodies against the pathogen.

Because the vaccine contains only a weakened or harmless version of a pathogen, the vaccinated person is not in danger of developing disease - although some people may suffer a mild reaction. If the person does get infected by the pathogen later, the required lymphocytes are able to reproduce rapidly and destroy it.

Monoclonal antibodies are laboratory-produced molecules engineered to serve as substitute antibodies that can restore, enhance or mimic the immune system's attack on cancer cells. They are designed to bind to antigens that are generally more numerous on the surface of cancer cells than healthy cells.

New medical drugs have to be tested to ensure that they work, and are safe, before they can be prescribed. There are three main stages of testing:

1. The drugs are tested using computer models and human cells grown in the laboratory. Many substances fail this test because they damage cells or do not seem to work.
2. Drugs that pass the first stage are tested on animals. In the UK, new medicines have to undergo these tests, but it is illegal to test cosmetics and tobacco products on animals. A typical test involves giving a known amount of the substance to the animals, then monitoring them carefully for any side-effects.
3. Drugs that have passed animal tests are used in clinical trials. They are tested on healthy volunteers to check they are safe. Very low doses of the drug are given to begin with. If there are no problems, further clinical trials are done to find the optimum dose for the drug.

Clinical trials are not without risk. Sometimes severe and unexpected side effects occur. Most substances do not pass all of the tests and trials, so drug development is expensive and takes a long time.

• Insect repellents
• Insecticides
• Caffeine
• Mint
• Cinnamon
• Ricin
• Citronella