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Biology Essay : How bacteria can affect the lives of humans and other organisms
Bacteria are a form of microorganisms and these can have huge impacts on the lives
of humans and other organisms
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Bacteria specifically can cause damage to
organisms as they can produce toxins which can cause damage and lead to the
destruction of cells
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Firstly with the gaseous exchange system some
examples of bacteria are tuberculosis and bronchitis
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Tuberculosis is a lung disease and is caused by mycobacterium tuberculosis and this
is spread through the air via liquid droplets by coughing and sneezing and this is a
form of resistant bacteria that can survive for several weeks even after it's dried out
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Bacteria can also cause damage through the digestive system for example cholera
via the mouth
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Another way in which tuberculosis and cholera can impact the lives of people is that
it is hard to control the diseases e
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It's difficult to use vaccines for cholera because it's an intestinal disease so it isn't
easily reached by the immune system so it isn't effective also the antigens of the
cholera pathogen rapidly changes its tertiary structure so it's difficult to produce a
long lasting, effective vaccine
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Another issue to treating disease such as TB is antibiotic resistance and this is
where the bacteria has adapted and changed its tertiary structure so its no longer
impacted the antibiotics so it can't as a treatment anymore
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Bacteriophages are viruses that infect bacteria
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The lysogenic cycle: The phage infects a bacterium and inserts its DNA into the
bacterial chromosome, allowing the phage DNA (now called a prophage) to be

copied and passed on along with the cell's own DNA which can overall reduce the
effect of bacteria to humans
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Bacteria are essential within nutrient cycles for example, the
phosphorus cycle this is where phosphorus is stored within the sedimentary rocks
where weathering and erosion causes the phosphorus to be released into the soil
where plants can take up this phosphate to form their biomass, animals can then
feed on these plants to help with the synthesis of DNA and helps with the production
of ATP and nucleic acids
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So this gives a positive effect on animals and plants which can help with growth and
repair via protein synthesis
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During the first stage
of the nitrogen cycle (nitrogen fixation) nitrogen fixing bacteria turns atmospheric
nitrogen (N2) into ammonia (NH3) there are 2 types of nitrogen fixing bacteria: free
living bacteria - these bacteria obtain the nitrogen containing compounds when the
plant dies
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The final stage is Denitrification where the Nitrates are converted back into
atmospheric nitrogen via denitrifying bacteria, this is normally in waterlogged soil
conditions
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Relating to both of these nutrient cycles, a key aspect is specifically the mycorrhizae
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It
helps with the absorption of water and nutrients such as phosphate and ammonium
ions

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