Micro-organisms

Viruses

• average size:0.0001mm
• Structure:A strand of genetic material wrapped in a protein coat
• Found:Viruses can only reproduce inside living cells
• Uses:The kill pest animals
• Diseases:Common Cold, flu, measles, AIDS etc

Bacteria

• average size:0.001mm
• Structure:Single celled with a strong cell wall
• Found:water,soil,decaying matter
• uses:yoghurt,cheese, vinegar
• diseases:Typhoid, cholera, food poisining

Fungi

The size varies from small enough for the eye not to be able to see it to mushroom size. Its structure is a strong cell wall. Found in soil, body and houses. Uses are in yeast and beer. It creates Athletes foot.

Fungi,Bacteria and Viruses

The differences between those three is that Fungi is the biggest microbe but has a nucleus and vacuole. A bacteria doesn't have a nucleus but some have tails called flagella. Bacteria are smaller than fungi. Viruses can only reproduce inside other living cells, they are the smallest microbe, they have strands of genes instead of a nucleus.

Yeast

Yeast produces CO2 because it respires and when something repires it realeses CO2.

aerobic production of bread=glucose+oxygen=CO2+water+energy

anaerobic production of bread=glucose=CO2+water+energy

Harmful                                          Useful

• Germs                                    yeast
• Mould                                     yoghurt

Killing harmful Bacteria

• Washing hands before you eat
• Covering your mouth when you cough or sneeze
• Keeping away from people if you are ill
• Avoid food if it's not fresh or not cooked properly
• Keeping uncooked meat in a different place to other food as it contains harmful bacteria.

Cholera Outbreak

The cholera outbreak started in 1854. Injust a few weeks thousands of people caught cholera in Soho. A scientist called John Snow suggested that cholera was caused by drinking infected water but everyone else thought it was from bad air. Once most people in Broad street caught cholera smith suspected something and he found out that most people who died lived near the Broad street pump. Only 5 out of the 500 people died at the local warehouse who had their own well. No one at the local brewery died as they were all drinking beer. Two ladys who lived 5 miles away died of cholera as they had a bottle of watter from Broad Street pump brought to them as they liked the taste. It showed that it was the infected water as there was a crack in the well which was right next to a sewage pit which had infected the water.

Natural Body Defenses

• Tears contain an enzyme that kill bacteria
• Hairs in your nose that traps micro-organsims and the mucus contains an enzyme that can kill bacteria
• Enzymes in saliva can kill bacteria
• Most bacteria swallowed with food and drink are killed by the stomach acid
• Skin is tightly packed layers of dead cells- most micro-oragnisms can't get in