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Bacteria make up, the basic structure....
1 Slime capsule Capsules can be a source of nutrients and energy to microbes.
2 Cell wall A backbone
3 Cell membrane a selective barrier
4 Cytoplasm include proteins ,vitamins, ions, nucleic acids and amino acids and,
carbohydrates, fatty acid.
5 Plasmids A plasmid is an extrachromosomal element, often a circular DNA.
6 Genetic material most cell's nucleus contain the genetic material, however, this is not the
case for bacteria.
7 Flagella The numbers of flagella, as well as their
location on the cell surface are characteristic of a species
How they cause disease...
Bacteria are single celled organisms 1/100th time smaller than a normal body cell. Once bacterium
has entered the body they (like viruses) reproduce. Bacterium does this by each splitting into 2
every 20 minutes, so within a suitable environment a single bacterium can reproduce and become
8 within the hour. They can continue to split at this rate (2 to 4, 4 to 8, 8 to 16...) until a factor within
their environment significantly changes. These then go on to make you feel very ill by producing
toxins and damaging your cells. However not all bacteria is bad some if in the right places can be
very useful like the ones used in you digestive system.
Viruses are not cells however they are tiny about 1/100th the size of a single bacterium.
These amazing organisums are no more than a coat of protein set around a strand of DNA or
genetic material. Like Bacteria they do not have a nucleus like most other cells.
How viruses cause disease...
To make you feel ill they (the Viruses) basically damage your body's cells by replicating
themselves when invading the nucleus of any body cell and using the DNA to produce many copies
of itself. The cell then bursts, releasing all the cloned or copied versions of itself to repeat this
process for the rest of the body. They then pass out through the bloodstream, the airways, or by
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First lines of defence...
Microbes can enter our bodies in many ways and it therefore is vital that we do have some
The first way pathogens can enter is through our skin and eyes however undamaged skin
is a very effective barrier against microbes. If it gets damaged, the blood clots quickly (due to the
Platelets of which are small fragments of cells, which have no nucleus but continuously travel
around in the Plasma) this keeps the pathogens out.…read more
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Second Lines of Defence...
As said before, as microorganisms enter the body, they release toxins and reproduce
rapidly and unless stopped the victim's health will become severely compromised. this is the job of
the immune system and the white blood cells.
What are they?
The main role of the white blood cell is to defend against disease, they have a large
nucleus and ingest the unwelcome microbes, and produce two different substances to fight
bacteria and protect the body.…read more
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Within Viral diseases
such as, colds and Flu's (carried by droplets in the air) polio (through drinking dirty water) HIV
(when a sharp object makes a break in the skin) hepatitis A (through eating contaminated
Unnatural defences... immunisation!
Once your white blood cells have produced antibodies to tackle a new strain of bacteria or
virus you have developed a "natural immunity" to it.…read more