Why Wash Your Hands

Prevention of Diseases Caused by Microorganisms

1. Some people believe that prevention is better than cure.

2. Diseases caused by microorganisms can be prevented by the following methods.
(a) Washing hands: Wash your hands with soap and water after you touch an animal, after using the toilet and before you handle or eat food.
(b) Boiling water: Most microorganisms die under high temperature, Therefore, all food or drink must be cooked or boiled thoroughly.
(c) Covering mouth: To help the people around you stay well, use a tissue to cover your mouth when you sneeze or cough. This is to prevent the microorganisms from being released into the air.
(d) Covering woungs: This can prevent the wound being infected by harmful microorganisms.
(e) Quarantine: Put the patients with contagious diseases under quarantine. This can help to prevent the spread of the diseases.

3. Washing fresh fruits and vegetables before eating them and storing and cooking food properly can also help you avoid getting contagious diseases.

Diseases Caused by Microorganisms

1. There are many types of diseases with many different causes.

2. Many diseases are caused by microorganisms like bacteria and viruses. Some are caused by fungi and protozoa.
     
      Diseases caused by microorganisms

• Bacteria - Cholera, Conjunctivitis, Mumps, Scabies
• Virus - AIDS, Flu, Cough, Measles, Chicken pox
• Fungi - Ringworm, Tinea
• Protozoa - Malaria

3. Diseases caused by micro organisms can spread from one person to another. These are called contagious diseases.

4. A contagious disease can spread through different ways such as air, food or water and direct contact.

5. Air
(a) Microoganisms are very small and light.
(b) Thus, when an infected person sneezes or coughs, these microorganisms are released into the air. Healthy people may inhale these microorganisms and get infected.
(c) An example of a diseases caused by fungi such as ringworm and tinea.

6. Direct contact
(a) Direct contact with a sick person can cause the microoganisms to spread and cause infection.
(b) Measles can spread from one person to another by direct contact such as shaking hands.
(c) The sharing of clothing or personal items such as towels, may lead to the spread of diseases caused by fungi such as ringworm and tinea.

7. Food or water
(a) Some diseases spread when people drink water containing harmful microorganisms. Cholera, caused by a bacterium, can spread this way.
(b) Other diseases spread when people eat food containing harmful microorganisms.
(c) Food which are not covered is exposed to microorganisms in the air. If a person eats the food, he will get infected.
(d) Food can be infected if it is prepared or handled in an unclean way, for example, handling food with dirty hands.

Harmful Effects of Microorganisms

1. Not all bacteria are useful. Some bacteria are harmful to people.

2. Harmful microorganisms include certain bacteria, virus, fungi and protozoa. These microorganisms can cause:

(a) illnesses

(b) food poisoning

(c) food to turn bad

(d) tooth decay

3. Food poisoning is caused by eating food that is infected by harmful microorganisms.

4. Food  poisoning can lead to stomach upset, diarrhoea and vomiting.

5. Spores of microorganisms such as bacteria and fungi in the air which land on our food make food turn bad.

6. Bacteria and fungi feed on the nutrients in food and their waste products (toxin) cause food to smell and taste bad.

7. Tooth decay also caused by microorganisms.

8. Food in our mouth and on the surface of our teeth encourages the growth of bacteria. The activity of these bacteria causes tooth decay.

Uses of Microorganisms

1. Some microorganisms are widely used in making food.
(a) Yeast (fungi) makes bread dough rise and the bread becomes fluffy.

(b) Other fungi are used in making soy sauce and tempe.

(c) Some bacteria turn milk into cheese.

(d) Some bacteria also turn milk into yoghurt.

2. Yeast is used in making tapai. Tapai is a tradisional food which is produces by the fermentation of glutinous rice or tapioca.
3. Bacteria that live in soil help to break down the remians of dead organisms. It helps in fertilizing the soil for plants growth.

Some Microorganisms are Harmful and Some are Useful

(a) Microorganisms can be useful or harmful.
(b) Useful microorganisms can be used in making food.
(c) Harmful microorganisms cause diseases.

Microorganisms Move

(a) Microorganisms move in their own ways depending on where they live.
(b) We can see the movement of microorganisms such as protozoa which live in water.
(c) The movement of microorganisms can be seen using a microscope.
(d) Most aquatic microorganisms move by whisking their tails rapidly in water.

Microorganisms Grow

(a) Mircoorganisme are found everywhere in our surroundings.
(b) When conditions are suitable, they grow very fast.
(c) Mould grows on moist bread. It gets its nutrients when the bread decay. It causes the bread to turn bad.
(d) Bread mould grows in a moist, warm airy environment.
(e) Other examples of food that can get mouldy or spoilt due to microorganisms are oranges and stale rice.

Microorganisms Breathe

(a) Yeast is an example of fungi.
(b) Yeast exists all around us - in soil, on plants and even in the air.

Fungi

(a) Fungi are the largest of the four types of mircoorganisms
(b) They live in soil,litter, on other organisms and even on our food.
(c) Fungi reproduce from spores.
(d) Mushrooms, moulds and yeast are examples of fungi.
(e) Some fungi, such as yeast , are so small that we need the help of a microscope to see them.
(f) Like bacteria, most fungi are harmless and many are helpful. However, certain fungi can cause diseases.

microorganisms under microscope

Protozoa

(a) Protozoa are larger than viruses and bacteria.

(b) They are aquatic organisms.

(c) Protozoa also can be harmless or harmful. Malaria is one disease caused by a type of protozoa.

Virus

(a)Viruses are the smallest microorganisms. They can only be seen using the most powerful mircoscopes.
(b)They can ifect plants, animals and bacteria.
(c)Colds ang flu are caused by viruses. Viruses are responsible for many serious and sometimes deadly diseases like AIDS.

Bacteria

(a)Bacteria are very tiny.

(b)They exist in various forms. Most bacteria can be classified according to their shapes.

(c)Bacteria can be found in the air, in water, in soil and on the surfaces that you touch.They live in your body too.

(d)Bacteria can reproduce very fast under a suitable temperature,and with enough water and food.

(e)Bacteria are most active in places that are warm, dark, moist and dirty.

(f)Most kings of bacteria are harmless, and many are eyen helpful.

(g)However, some kinds of bacteria cause diseases such as diarrhoea, sore throat, etc.

(h)Bacteria which cause diseases called germs.

Types of Microorganisms

there are four main types of microorganisms:

(A)bacteria

(B)virus

(C)fungsi

(D)protozoa