B2- KEEPING HEALTHY
MICRO-ORGANISMS AND DISEASE
§ Micro organism include things like bacteria, viruses and fungi
§ Some of these can cause infectious diseases
§ Infections can cause fevers, sick stomachs, sickness, or rash. These are called symptoms different micro organisms cause different kinds of harms to the body. This damage is done to the body’s CELLS
§ Some damage cells directly. Malaria causes blood cells to burst after they duplicate. They give flu-like symptoms
§ Many infectious micro organisms can produce toxins that damage cells.
§ Some bacteria produce proteins which damage the material holding the cells together. This causes bacteria to invade the body more deeply. (food poisoning- staphylococcus)
§ Toxins in cells cause fever or inflammation.
§ Bacteria multiply every 20 minutes. For this they need warmth, nutrients and moist conditions
§ In the body, there are lots of places with these conditions e.g. intestines.
§ Few bacteria can become a large colony inside the body
§ Need cells to reproduce
§ Use parts of other cells to make copies of themselves
§ Certain viruses can reproduce easily because there are lots of the right kinds of cells in the human body
CALCULATING THE GROWTH OF MICRO ORGANISMS:
§ They make copies asexually.
§ If at the start you have 1 MO, at 20 mins you will have 2 and at 40 mins you will have 4 so on
§ You must know (to work it out)
Should always be in minutes or hours. Both…