http://www.sherwood.k12.or.us/?q=node/522
Taken from: Porter, S. (2003). Microbes and disease.
http://mrsimonporter.wikispaces.com/Year+8+Science
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As the name suggests, MICROBES are
microscopic organisms.
They can only
be seen using a
microscope.
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Microbe can be put into a number of categories. The four
types which you need to know about are listed below:
BACTERIA
VIRUS
FUNGI
PROTOZOA
A living organism must be able to
demonstrate that it can perform ALL the 7
life processes.
Movement
Respiration
Sensitivity
Growth
Reproduction
Excretion
Nutrition
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Microbes multiply very
rapidly. Two can, very
quickly, become four then
eight and so on.
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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.
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REVIEW of
past
concepts....
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Chemical Energy
and Food
REVIEW of
past
concepts....
– Organisms get the
energy they need
from food.
– Food molecules
contain chemical
energy that is
released when its
chemical bonds
are broken
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Cellular respiration is the process
that releases energy from food in the
presence of oxygen. It happens in the
mitochondria of the cell.
REVIEW of
past
concepts....
– In symbols:
6 O2 + C6H12O6  6 CO2 + 6 H2O + Energy
– In words:
Oxygen + Glucose  Carbon dioxide + Water + Energy
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Microbe uses
Yeast is a microbe which RESPIRES to give off carbon
dioxide. This is used in baking bread and in winemaking.
We can use the AEROBIC respiration of yeast to
make bread rise. Yeast uses the sugar in bread
dough to respire.
The reaction of CELL RESPIRATION (the same
done for most of our cells in the mitochondria) is:
Glucose + oxygen
carbon + water + energy
dioxide
C6H12O6 + 6 O2
6 CO2 + 6 H2O + ATP
The carbon dioxide given off causes the bread to rise.
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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.
Yeast converts the sugar into
alcohol:
carbon
Glucose
+ ethanol + energy
dioxide
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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.
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Bacteria
A bacteria is a single celled organism which does not
completely have a nucleus. Their genes are found in the
chromosomes.
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Fungus
Yeast is a fungus and as can be seen below, it has a more
complex structure than the other two types of microbes.
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