Keeping Healthy

• Carbohydrates, fats and protiens are used by the body to release energy and build cells
• Mineral ions and vitamins are needed for a healthy functioning body
• A person looses mass when the energy content of the food eaten is less than the amount of energy needed.
• The rate at which all the chemical reactions in the body take place is called the metabolic rate. This varies with the amount of activity you do.
• The metabolic rate can also be affected by inherited factors.
• Cholestrol is a substance found in the blood- It is made in the liver and needed for healthy cell membranes. 
• The blood stream transports cholestrol around the body attatched to protiens.
• This combination is called a lipoprotien
• Low Density Lipoprotien- LDL's- Carry cholestrol from the liver to the cells ('bad cholestrol'- build up fat on artery walls-cause heart disease)
• High Denisty Lipoprotien- HDL's- Carry excess cholestrol from cells back to liver.('good cholestrol' stop fat building up on artery walls) 
• Vegetable oil helps lower the amount of cholestrol in blood and increase proportion of HDL's to LDL's.

• Pathogen- A disease causing organism. (Bacteria, Virus, Fungi)
• Antibodies- White blood cells produce antibodies to fight disease (Antibodies and antitoxins are not living things, they are specialised protiens)
• Antigens\Markers- Found on all cells It recognises self\non-self bacteria and if it doesnt belong to itself it will produce antibodies.
• 2 Types of white blood cells - White blood cells produce anti toxins that stick to make the toxins (produced by pathogens) neutralise (stop working) - Producing Antibodies that fight a particular bacteria/virus - Engulfs/Ingests the bacteria.
• Virus'- Reproduce inside host cellsand damage the cell whilst doing this. Gets inside cell and makes thousands of copies of itself. Eventually the virus takes over the entire host cell and it explodes. The virus is then passed into the bloodstream and airways.
• Vaccination- Vaccination involves putting a small amount of an inactive form of a pathogen, or dead pathogen, into the body.
• Ignaz Semmelweiss realised the importance of cleanliness in hospitals. To wash hands before seeing to patients, this greatly decreased the number of deaths of infectious diseases. 

Medicenes

• Painkillers: Painkillers help to relieve the symptoms of an infectious disease but do not kill pathogens involved. Paracetamol, aspirin and morphine block nerve impulses from the painful part of body.
• Antibiotics- Kill bacteria and stop their growth. Do not work against virus' as they live inside and reproduce inside cells. Different antibiotics work in different ways, it is important that specific bacteria is treated with specific antibiotics. 

• Bacteria strains  can develope resistance to antibiotics due to natural selection. In large amounts of bacteria some will not be affected by the antibiotic. They survive and reproduce producing more cells not affected by the antibiotic. 
• MRSA- A strain of bacterium that is resistant to most antibiotics. Vaccinations and antibiotics will no longer work. This will spread. New antibiotics must be developed
• Actions of Antibiotics and disinfections can be investigated using cultures of organisms in petri dishes.