© Boardworks Ltd 2003 Taken from: Porter, S. (2003). Microbes and disease. 8+Science .

© Boardworks Ltd 2003

MICROBIOLOGY

FERMENTATION

& DISEASES

Taken from: Porter, S. (2003). Microbes and disease. http://mrsimonporter.wikispaces.com/Year+8+Science

http://www.sherwood.k12.or.us/?q=node/522


As the name suggests, MICROBES are microscopic organisms.

They can only be seen using a microscope.


MovementRespirationSensitivityGrowthReproductionExcretionNutrition

A living organism must be able to demonstrate that it can perform ALL the 7 life processes.

Microbe can be put into a number of categories. The four types which you need to know about are listed below:

Microbe uses

BACTERIA VIRUS FUNGI

PROTOZOA


Microbe pictures

Microbes multiply very rapidly. Two can, very quickly, become four then eight and so on.


Microbe uses

Microbes have many uses. This is mainly because we can ‘grow’ microbes if we wish to.

Microbes (in this case bacteria) will grow in milk to make it ‘go off’. This is used in the yoghurt making process. Cheese is also another product made due to the use of microbes in industry.


Yeast is a microbe which RESPIRES to give off carbon dioxide. This is used in baking bread and in winemaking.

Microbe uses

We can use the AEROBIC respiration of yeast to make bread rise. Yeast uses the sugar in bread dough to respire. The reaction is:

Glucose + oxygen + water + energycarbon dioxide

The carbon dioxide given off causes the bread to rise.


Microbe uses

We can use the ANAEROBIC respiration of yeast to make beer and wine. This means that the yeast respires WITHOUT oxygen. This process produces alcohol (ethanol) and is known as FERMENTATION.

Glucose + ethanol + energycarbon dioxide

Yeast converts the sugar into alcohol:


Virus

A virus is a simple organism which does not completely display ALL the characteristics of living things. It consists of a protein coating and a strand of genes.


Bacteria

A bacteria is a single celled organism which does not completely have a nucleus. Their genes are found in the chromosomes.


Fungus

Yeast is a fungus and as can be seen below, it has a more complex structure than the other two types of microbes.


Microbes can cause disease

The diseases and their severity caused by microbes depend on the type of microbe. Some of these are listed below.

VIRUSES BACTERIA

Influenza (flu) Food poisoning

Mumps Sore throats

Chickenpox Tuberculosis (TB)

Smallpox Tetanus

Polio Cholera

Rabies Typhoid

German measles Whooping cough

FUNGI

fungal sinusitis

Athletes foot

OnychomycosisCauses discoloured

toe nails

Viralmeningitis

Bacterialmeningitis


How do microbes enter the body

Mouth

Skin

Cuts

Nose

EarsEyes

Genitals

A number of these places where microbes can enter the body are defended.


The spreading of microbes and disease is known as Transmission.

How do microbes spread?

Dirty water can transmit many diseases, for example, cholera which can be transmitted by drinking the water.

• Transmission in water

A cough or a sneeze can release millions of microbes into the air which could then infect somebody else.

• Transmission by air


• Transmission by animals

An animal, e.g. a mosquito (which spreads the MALARIA PARASITE) can carry the microbe from one place to another.

Many microbes can be exchanged from one person to another by direct or indirect contact:• Direct contact by hand.• Indirect contact by walking on a wet floor

already contaminated by someone else who has Athlete’s foot.

• Sexual contact.

• Transmission by contact


• Transmission by contact

There are other forms of indirect contact, the transmission of microbes from mother to unborn child.

If the mother develops the HIV/aids infection, it can be passed on to the unborn child through the placenta.

Transmission through the Placenta

Transmission via Breastfeeding

A child can also pick up microbes from the mother, via the milk, if the child is being breastfed.


How do we stop microbes spreading disease

We can prevent the spread of disease by making sure that good hygiene is used in key places such as bathrooms and kitchens.

Chemicals called antibiotics can be used to treat bacterial infections.

People can be immunised against some diseases by the injection of a vaccine.


Fighting disease


2. We will start a lab practice: Diversity of microorganisms in our environment. You need to bring:- Lab coat (no body can enter with out one) - In groups of 3, select 4 different places around the school

to compare the diversity of microbes between them.

For Thursday 26th January

1. HOMEWORK: On your notebook. - Summary about the types of transmission.- From tha table on page 11, select 5 diseases caused by

virus and 5 caused by bacteria and find the scientific name of the microbes that cause them.

- Afterwards, select one disease and explain the way it is transmitted and its treatment.

© Boardworks Ltd 2003 Taken from: Porter, S. (2003). Microbes and disease. 8+Science .

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Transcript of © Boardworks Ltd 2003 Taken from: Porter, S. (2003). Microbes and disease. 8+Science .