Healthy Diets Correct balance of the different foods which our body needs: carbohydrates, fats, proteins, vitamins, minerals, and water. A person is malnourished if their diet isn't balanced. Leads to a person being too fat or too thin. Can lead to deficiency diseases and conditions such as Type 2 diabetes.
Exercise Increases the amount of energy expended by the body. A person will lose mass if the energy content of food taken in is less than the amount of energy expended by the body. People who exercise regularly are usually healthier than people who take little exercise.
Metabolic Rate The metabolic rate is the rate at which all chemical reactions are carried out in the cells of the body. The rate varies with The amount of activity you do (your metabolic rate increases with the amount of exercise you do, and stays high for some time afterwards. The proportion of muscle to fat in your body.
Bacteria and Viruses They are pathogens. The differences Defence against Pathogens White blood cells ingest pathogens produce antitoxins to neutralize toxins produce antibodies to destroy particular pathogens (this leads to immunity from that pathogen) Bacteria: very small, reproduce very quickly, can produce toxins that make us feel ill, responsible for illnesses such as tetanus, cholera, tuberculosis Viruses: smaller than bacteria, reproduce very quickly once inside the living cell (which is then damaged), can produce toxins, responsible for illnesses like colds, flu, measles, polio
Treatment for Diseases Painkillers Antibiotics Vaccination Alleviate symptoms but don't kill pathogens Often used to kill bacteria inside the body Cannot kill viruses Overuse of Antibiotics Specific bacteria have to be treated with specific antibiotics It is difficult to develop drugs that kill viruses without damaging the body's tissues When antibiotics are overused, the bacteria may mutate to develop strains that are immune to that certain antibiotic Some individual bacteria may have natural resistance to an antibiotic When bacteria of the non-resistant strain are killed, the resistant strain survive and reproduce, thus increasing the population of the resistant strain A person acquires immunity to a particular disease by being vaccined An inactive/dead pathogen is injected into the body If a large proportion of the population are immune to a pathogen then the spread of the pathogen is very much reduced White blood cells produce antibodies to destroy the pathogen White blood cells are now sensitized to this pathogen and will respond to any future infection rapidly and therefore the body has acquired immunity to this pathogen
Preparing Cultures Culture Medium Uncontaminated Cultures Microorganisms can be grown in culture mediums containing various nutrients that the microorganism may need May include: carbohydrates, mineral ions, vitamins, proteins Agar is most commonly used as the growth medium Soft jelly-like substance that melts easily and re-solidifies at around 50 degrees Celsius The other nutrients are added to agar in order to provide the ideal growing conditions for cultures Required for investigating the action of antibiotics and disinfectants Sterilization of petri dishes and culture medium using an autoclave Sterilization of inoculating loops (do not blow on the loop or wave it around as it will pick up more microorganisms) Sealing the petri with tape dish after the agar has been poured in and allowed to cool. The dish should be stored upside down so the condensation forms in the lid.
Ignaz Semmelweiss Reduced patient deaths in wards from 12% to 1% in his local hospitals by insisting that doctors washed their hands after surgery and before visiting another patient His work and the work of other subsequent scientists has led to the creation of many modern hygiene standards in hospitals and has reduced the chance of infections being spread
B1 Keeping Healthy