biology

diet and exercise;

• A healthy diet ha the right balance of carbohydrates, fats and proteins.
• Minerals ions and vitamins are needed to stay healthy.
• If the diet is unbalenced you would become malnourished
• metabolic rate is the rate that chemical reatctions in cells work at.

weight problems;

• If the energy you take in equals the energy you use then your mass will stay the same.
• Eating too much can lead to being overweight, obese or having type 2 diabetes (high blood sugar)
• the opposite of this is a dificiency disease due to ack of vitamins or minerals.

Inheritance, excercise and health;

• your metabolic rate can be effected by genes.
• there are two types of cholesterol, you need 'good' cholesterol for your cell membranes to make vital substances.
• few people inherite high levels of 'bad' cholesterol wich can lead to heart disease.
• by exerciseing a person can increase their metabolic rate and lower high cholesterol levels.
• pathogens and disease;

• pathogens can casue infectious diseases. Pathogens are tiny microorganisms- usually bacteria or viruses
• ^these reproduce rapidly when entered the body, producing toxins (poisons)
• they make you feel ill by damaging cells.
• semmelweiss realised that infection could be pased from patient to patient through the doctors, he made his staff wash their hands before and after treating a patient.

Defence mechanisms;

• the skin acts as a wall to stop pathogens. They are also trapped by mucus and kille by stomach acid.
• white blood cells  are also part of the immune system: they ingest pathogens, they produce antibodies to help distroy them, they produce antitoxins to counteract the toxins that pathogens produce.

using drugs to treat disease;

• Antibiotics kill bacteria in the body.
• pennacilin in an antibiotic, but there are many others. it was descovered by flemming in 1928.
• viruses are hard to kill becasue they reproduce inside body cells so any treatment used could harm the body cells.

growing cultures for bacteria;

•  liquid or gel containing nutrients- a culture medium (agar jelly)
• warmth and oxygen
• incubated at 25 degrees c in a lab or 35 degrees c in industry.

changing pathogens;

• some pathogens, mainly viruses can mutate creating a new form of itself (a mutation)
• very few people are immune to these so disease spreads quickly.
• In a country= epidemic
• world wide= pandemic
• The MRSA 'super bug' is a bacteria that have evolved through natural selection, it has become resistant to the common antibiotics. 

immunity;

• dead or ineffective pathogens are used to create a vaccine.
• white blood cells make react by producing antibodies.
• this makes the person immune.
• the antibodies recognize the antigen [the shape] of the pathogen if they come across it again.
• the MMR vaccination is one of several. it prevents measles mumps and rubella

how do we deal with disease?.

• most people in a population are vaccinated to protect society form serious diseases.
• diseases such as measles can lead to long term damage to the body, such as deafness and occasionally death.
• over use of antibiotics can lead to the development of new strains of bacteria.