do the experiment at the start of this session, watch it develop as the topic gets explored


Why do we miss school ?

Why do we get sick ?

germ theory


The word Influenza, comes from Italian for 'Influence' ,

the term was originally used because the illness was attributed to astrological origins.

It then became, influenza del freddo, influence of the cold.

Influenza was 1st used in english in 1743

Our bodies are not usually sick,

The first line of defence is the body's natural barriers. These include:

  1. skin
  2. nasal hairs, mucus and cilia
  3. tears

Then in the blood, platlets serve to close wounds quickly, and form a barrier to pathogens

The last natural line of defence is the white blood cell


Bacteria and Viruses are called Pathogens


the cell is oval, with tail-like features attached to the outside

Salmonella bacterium cell

Bacteria come in many shapes and sizes, but even the largest are only 10 micrometres long (10 millionths of a metre). Bacteria a single celled organisms, that means they are each only one cell in size. The bacterium cell does not have a nucleus but their genes are carried on a loop of DNA in the cytoplasm.Bacteria are much too small to see, yet they cause many diseases of plants and animals whose effects can be seen.Bacteria are living cells and, in favourable conditions, can multiply rapidly. Once inside the body, they release poisons or toxins that make us feel ill.They are often spread in dirty water, but can be killed by boiling this water.

Examples of Bacterial Diseases

Diseases of humans include actinomycosis, anthrax, brucellosis, bubonic plague, cholera, cystitis, dental caries (tooth decay), diptheria, dysentery, food poisoning, gangerine, gastroenteritis, gingivitis, gonorrhoeae, infection of post-operative wounds, infectious jaundice, legionnaires disease, leprosy, meningitis, pinta, pneumonia, psittacosis, pus-forming diseases, rat-bite fever, relapsing fever, rheumatic fever, rocky mountain spotted fever, scarlet fever, septicemia, shigellosis, skin infections, syphilis, tetanus, trachoma, tuberculosis, typhoid fevers, typhus, whooping cough and yaws.

Bacterial infections can be cured by the use of an anti-biotic when symptoms get bad.

However it's not all bad news. Bacteria can bring some benefits too.

Despite their relative simplicity, bacteria carry out most of the key chemical changes of carbon, nitrogen, and sulfur in the living world. The eukaryotes, like us humans, perform relatively small changes to their molecules.

Benefits of bacteria include:

* Bacteria are the only living things which can fix nitrogen. They are therefore essential to all other life on Earth.

* Some plants such as beans keep nitrogen fixing bacteria as symbionts in nodules on their root.

* Bacteria are the major decomposers of dead plants and animals, so freeing their atoms to be re-used by other living things.

* Cows and other animals keep bacteria in their stomachs, as only bacteria can break down the tough cell walls of plants.

* People use bacteria to turn wine into vinegar and milk into cheese and yogurt.

* They are increasingly used in biotechnology to manufacture proteins.

Bacteria need

  • Food
  • Water
  • Suitable temperature
  • Suitable pH

in order to survive.

Making Cheese

Milk is heated to 70 C for 30 minutes to kill harmful bacteria. This is called pasteurisation.

After cooling to 30 C useful bacteria are added.

These bacteria produce an enzyme which changes lactose into lactic acid.

This makes the milk turn sour.

Rennet is added which contains the enzyme rennin. This makes the milk curdle.

The lumps are called curds and these are the basis for cheese.

Other bacteria or fungi are added to ripen the cheese. This gives each type of cheese its characteristic smell and flavour.


Viruses are many times smaller than bacteria. They are the smallest organisms known and consist of a fragment of genetic material inside a protective protein coat.

Structure of Viruses

• Tiny structures

• Outer protein coat

• Strand of either DNA or RNA

• No cell membrane of organelles

Viruses can only reproduce inside host cells,

and they damage the cell when they do this.

A virus can get inside a cell

and, once there, take over

and make hundreds of thousands of copies of itself.

Eventually the virus copies fill the whole host cell and burst it open. The viruses are then passed out in the bloodstream, the airways, or by other routes.

A virus has no ribosomes, water molecules or cell membrane. It cannot build any proteins itself, so it is not a living thing, but it does contain a chromosome which it can inject into a living cell.

When a cell is infected, the virus's genes are taken into the cell's chromosome, -where they begin to give out messages for making new viruses.

The infected cell is turned into a factory for making copies of the virus.

When it is full of viruses the cell bursts open, sending out millions of viruses to infect more cells.

spherical shaped virus showing a cross-section through the core

Hepatitis C virus. DNA are enclosed in a protein coat.

Shapes of Viruses

1. Rod-shaped

2. Round

3. Complex

Virus Replication

1. A virus lands on a host cell.

2. Virus’s nucleic acid enters the cell.

Viruses cause many diseases in plants and animals.

For example the human virus diseases include acquired immune deficiency syndrome (AIDS), burkitt's lymphoma, chickenpox, the common cold, conjuctivitis, creutzfeldt-jacob disease (CJD),(mad cow disease), encephalitis, enterovirus disease, gastrointestinal infections, glandular fever, hepatitis, herpes simplex, infectious mononucleosis, influenza, kuru, lassa fever, measles, mumps, polio, rabies, respiratory infections, rubella (german measles), shingles, smallpox, some cancers, warts and yellow fever.


However, viruses also bring some benefits.


more more more



Fungi not only feed on dead matter.

They can also invade living plants and animals.

Fungal diseases affect many of our crops, as well as causing human diseases such as athlete's foot, dermatitis, and ringworm

Fungi thrive in damp conditions.

Examine yeast and two fungi.

bakers yeast. Two hosts. Sealed boxes, (clean chinese take away boxes - Ireland), Microscope. Slides & coverslips.

Use instructions on back of bakers yeast, to wake the yeast.

By spooning the soaked spore masses onto the hosts

Grow two fungi,

1 on tomatoes or orange

and 1 on bread.

in the sealed boxes

Observe/Draw on a daily basis.

The worlds most dangerous fungus ??


follow these other links to help learn about different species of fungus and their mushroom



Could you name 5 clean surfaces, and 5 dirty surfaces?

OB65 investigate the presence of micro-organisms in air and soil

Follow on here

OB66 state two uses of biotechnology in industry and two uses of biotechnology in medicine

Making of alcohol


The making of beer is a very simple transformation of sugar molecules, in grains, to ethanol molecules. The fungus Yeast does this and also gives off CO2.

Yeast (a micro-organism) contains enzymes which change sugar into ethanol (alcohol).

A second product of the reaction is carbon dioxide.

Uses of fermentation include:

Beer Brewing, Wine making, bread baking

Cheese! We would have no cheese without bacteria


Or Yoghurthttp://howto.wired.com/wiki/Make_Your_Own_Yogurt

Enzyme action in washing powders



Vaccines are when a bacteria or virus similiar to another (more dangerous) bacteria or virus is given to a human. The Humans immune system attacks & destroys this alien pathogen. The immune system has now learned how to destroy this bacteria / virus and will be able to do so again in the future.

Worlds 1st Vaccine,

On 14 May 1796, Edward Jenner tested his hypothesis by inoculating James Phipps, a young boy of 8 years (the son of Jenner's gardener), with material from the cowpox blisters of the hand of Sarah Nelmes, a milkmaid who had caught cowpox from a cow called Blossom,[7] whose hide hangs on the wall of the library at St George's medical school (now in Tooting). Blossom's hide commemorates one of the school's most renowned alumni. Phipps was the 17th case described in Jenner's first paper on vaccination.

A Non life threatening Virus can be given to a human patient to make them IMMUNE to similar viral threats. This is known as immunisation.

Sir Alexander Fleming (6 August 1881 – 11 March 1955) was a Scottish biologist and pharmacologist. Fleming published many articles on bacteriology, immunology and chemotherapy. His best-known achievements are the discovery of the enzyme lysozyme in 1923 and the antibiotic substance penicillin from the fungus Penicillium notatum in 1928, for which he shared the Nobel Prize in Physiology or Medicine in 1945 with Howard Walter Florey and Ernst Boris Chain.[1]


It must be understood that penicillin is a secondary metabolite of fungus Penicillium, which means the fungus will not produce the antibiotics while it is growing, but will produce penicillin when it feels threatened. There are also other factors that inhibit penicillin production. One of these factors is the synthesis pathway of penicillin

Antibiotic's (medicines that fight bacterial infections) are made by Fungi in response to percieved threats. We harvest this and make antibiotics

biotechnology in industry and medicine


While fungi usually grow on dead humas and dead wood, research is now being put into fungi that eat plastics at the City of Manchester University

Enzymes in the washing powders are used to digest some stains. Proteases would remove protein stains such as blood. Lipases would remove fat stains and cellulases remove loose bobbles

OB67 list three common illnesses caused by viruses and three caused by bacteria.

click on the following link to determine who where and why people are dying



or search the machine you are working on for bodgbddeathdalyestimates

Top Killers

Communicable, maternal, perinatal and nutritional conditions A. Infectious and parasitic diseases 1. Tuberculosis 2. STDs excluding HIV a. Syphilis b. Chlamydia c. Gonorrhoea 3. HIV/AIDS 4. Diarrhoeal diseases 5. Childhood-cluster diseases a. Pertussis b. Poliomyelitis c. Diphtheria d. Measles e. Tetanus 6. Meningitis 7. Hepatitis B (g) Hepatitis C (g) 8. Malaria 9. Tropical-cluster diseases a. Trypanosomiasis b. Chagas disease c. Schistosomiasis d. Leishmaniasis e. lymphatic filariasis f. Onchocerciasis 10. Leprosy 11. Dengue 12. Japanese encephalitis 13. Trachoma 14. Intestinal nematode infections a. Ascariasis b. Trichuriasis c. Hookworm disease B. Respiratory infections 1. Lower respiratory infections 2. Upper respiratory infections 3. Otitis media

Don't forget food poisioning


Water pollution Culture bacteria and/or fungi.

Agar plates. Inoculating loop. Bunsen burner. Oven. Labels. Microscope. Slides & coverslips

Pre-prepared agar plates.

Use two water samples from different sources.

Lake or stream water could be used.

Compare both samples.

Observe and draw.


BBC tells us how to fight infection


They then tells us if pro-biotic works!

You could also explain this as Scientific reason!

Testing effectiveness of disinfectant on food spoilage organisms.

4 petri dishes containing bacteria grown using food stuffs.

3 commercially available disinfectants.

3 pieces of filter paper soaked in each of the disinfectants.

Place soaked filter papers in 3 dishes.

Label each with the name of the disinfectant

as a control no disinfectant in the 4th dish.

Observe and compare.

Algae & Protazoa

Algae range from single celled ________ up to complex multicelled seaweeds


are single celled organisms.

They are the cause of Malaria and sleeping sickness,

However the can be used to treat sewage, killing the harmful bacteria in the sewage.