8C MICROBES AND DISEASE
MICROBES
• What is a microbe?
• What are the three types of microbes? Give an
example of each.
• What do we use microbes to make?
Top trumps
Micro-organisms
The word MICRO
means very small.
(So you need a
Microscope to see
it!)
http://www.cellsalive.com/howbig.ht
m
Micro-organism Man!

Micro-organisms
Micro-organisms
Micro- very small
Organism- a living thing.
So Micro-organisms are very
small living things!
N.B Viruses are often classed as microorganisms but technically they are NON-Living
so call them Microbes instead!
Microorganism
man

Microbe uses carousel
• You will be assessed in this activity for AF2
Seven wonders of the microbe world
Bread mould experiment
• You are going to look at mould growing on bread
over 2 weeks.
Diseases
• What is the scientific word for a microbe that
causes disease?
• Name an example of a disease caused by a
bacteria, virus and fungus?

Bacteria
The good the bad and the ugly!
Bacteria are small living single celled
organisms that can come in good
(beneficial) forms and bad (pathogenic)
forms that cause disease.
Some
different
shapes of
bacteria
Bacteria can double in number every
20 minutes!
The motility (movement) of some
bacteria in culture.
How fast!

Pseudomonas aeruginosa
Good bacteria
Bacteria help to
break down
faeces (poo) in
sewage works.
Bad bacteria in the mouth
cause teeth to rot.
Mouth bacteria
Mouth bacterium
MRSA- the bacterial superbug!
Methicillin Resistant
Staphylococcus aureus
Methicillin
(an
antibiotic)
WON’T
Work to
cure this
infection!

Bacteria
Cell wall
Cytoplasm
Cell membrane
Circle of DNA
Bacteria
Cell wall
Cytoplasm
Cell membrane
Circle of DNA
Sometimes has a TAIL to help it
swim
Structure of
viruses
How viruses replicate
inside cells
Examples of
viruses
A T4 bacteriophage. This
infects only bacterial cells,
in this case only E. coli
The HIV virus. This attacks
T4 lymphocytes. It is
responsible for AIDS.
One sneeze can transmit
many cold virus particles

Bird flu virus

Measles virus
Electron microscope
picture of the
measles virus
Boy with measles
Viruses cause
warts,
cold sores and verucae
Conjunctivitis
Foot and mouth disease is caused by a
virus and is VERY infectious for cows
From
this
To this
Treatment of
viral infections

Virus
Protein Coat
Strand of DNA
Virus
Protein Coat
Strand of DNA
SMALLEST microbe
Also NOT technically alive…
Fungi
Why did the mushroom want
to go out with the toadstool?
Because he was a Fungi to be
with!
Fungi are organisms that produce spores
and come in the form of moulds, yeasts,
mushrooms and toadstools.

They also help things to rot and breakdown
which is an essential process in the cycle of
life.
Examples of fungi
Mould growing a
bread bun
There can be good forms of
fungus (used to make
bread/beer) and bad forms
(Mould, Athletes foot and
thrush).
Yeast cells budding
Mould and fungus causes things
to breakdown
Fungus taking
over
Athletes
foot
Oral thrush
Thrush yeast cells
Fungi
Cytoplasm
Cell membrane
Cell wall
Nucleus
Starch granule
Vacuole
Fungi
Cell wall
Starch granule
Vacuole
Nucleus
Cytoplasm
Cell membrane
BIGGEST
microorganism
Sort the cards into if they are caused
by a bacteria, virus or fungus
MICROBE BINGO
Similarities and differences
• What do bacteria and viruses have in common?
• How are viruses different to bacteria and fungi?
Mould
• What is mould?
• Why does food go mouldy?
• Name 5 different methods of stopping mould
growth and explain why they stop it.
Mould investigation
Aim: To investigate how to stop mould growing in
gravy
Variables
Independent:
Dependent:
Control:
Prediction
• http://www.ehow.com/how_6317533_makenutrient-agar-home.html
Gravy experiment results and
conclusion
PEER ASSESSMENT FOR AF5
Yeast
• What type of microbe is yeast?
• What do we use yeast to make?
• What types of respiration does yeast do?
Plan an investigation into one factor
that affects yeast growth
• You are going to put yeast, sugar, a drop of
washing up liquid and warm water in a
measuring cylinder
• Choose one factor to change and investigate
Write the Aim, prediction, and variables
Aim: to observe yeast growth
Time (mins)
Height of bubbles (mm)
The first line of defense
• How can diseases be passed from one person to
another?
• What is the bodies’ first line of defense to stop
microbes entering?
Bread mould 2 week results
Match the defense mechanism to its
use
The immune system
• What is the immune system?
• Which cells defend us against disease?
• How do they defend us?
Video
Vaccination
• Which cells produce antibodies?
• How do these cells respond when the body is
infected?
• Why do vaccinations stop you getting ill again?
Video