BTEC LEVEL 3 ASSIGNMENT 12A -Investigate different types of diseases and infections that affect humans
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ASSIGNMENT 12A
Investigate different types of diseases and
infections that affect humans
P1 - EXPLAIN THE CHARACTERISTICS
OF THE FIVE MAIN TYPES OF
PATHOGENS AND A DISEASE CAUSED
BY EACH.
A pathogen is a microorganism that has the ability to cause disease.
Pathogens are classified into different groups based off of their features, life
cycle and characteristics. The main five categories of pathogens are Protozoa,
fungus, parasites, viruses and bacteria. In this section of the assignment I will
discuss the features, characteristics, life cycle as well as the illness associated
with each pathogen.
CHARACTERISTICS OF PATHOGEN 1 – BACTERIA
bacteria is a classified group of pathogens which hold certain characteristics.
One of the many characteristics of bacteria is that they are defined as
prokaryotes since the organelles contained within bacteria lack the presence
of a membrane as well as a nucleus to hold its genetic information. The
genetic information of the bacteria is instead held within plasmids or is free
within the cytoplasm. The plasmids contain particular genes which assists in
antibiotic resistance. Additionally bacteria has the characteristic of being
unicellular meaning that bacteria is compromised of only one cell rather than
a range of different cells. Bacteria is encapsulated by an outer cell wall made
of a peptide linkage known as peptidoglycan. Lastly bacteria has the capacity
,to be able to divide at a rapid rate thus causing infection associated with this
pathogen to spread quicker.
Structural features of bacteria
there are many types of bacteria solely based off of their structure. Cocci is a
form of bacteria which is classified by a spherical oval shape, any bacteria
which takes this shape is considered to be cocci with a diameter around 0.5-
0.1 µm. Additionally bacilli bacteria has a rod shaped structure such as gram
positive bacteria with an average width of 0.5-0.1 µm In contrast bacteria
that has a curved structure is referred to as vibrio such as gram negative
bacteria with a length of around 2–3 μm. These are some of the many
structural features/shapes of bacteria. All bacteria posses a structure known
as flagella comprising of a protein known as flagellin allowing bacteria to
perform the function of movement. As well as flagella bacteria own a
structure known as the capsule which is the most outer layer which aids as
hydration preventing it from drying up. Moreover bacteria contain much
smaller ribosomes in comparison to eukaryotic cells (8OS) in this case the
ribosomes are known as (7OS ribosomes) responsible for the synthesis of
proteins. In order for bacteria to stick to other surfaces or bacterium
structures on the outside layer of the bacteria known as pilli aid in doing so.
These structures are often similar to the shape of hair.
Gram positive and gram negative bacteria
Some bacteria can be classified as gram negative or gram positive bacteria
where both types of bacteria have significant differences in terms of their
structural features. Gram positive bacteria is classified by having a thicker
peptidoglycan wall with the absence of an outer plasma membrane however
they do contain an inner plasma membrane. Since gram positive bacteria has
they no outer plasma membrane the crystal violet stain being used is able to
surpass and enter through to the thick peptidoglycan wall thus retaining the
stain. However in contrast gram negative bacteria has a much thinner
Peptidoglycan wall in comparison as well as the presence of an outer plasma
membrane. For this reason gram bacteria does not retain the crystal violet
2
, stain since the presence of an outer membrane acts as a barrier preventing
the crystal violet stain from surpassing.
The diagram on the right is an
illustration of both gram negative and
gram positive bacteria with their
structural features labelled
for bacteria to undergo full growth
there are four stages involved within
their life cycle. These four stages will https://www.thou
be discussed. The first of the four ghtco.com/bacter
stages is known as the lag phase. al-growth-curve-
This phase involves the adaptation of phases-4172692
bacteria against its environmental
conditions and metabolic activity taking place. In the duration of this period
the size of bacteria starts to increase rather than the number of bacteria
multiplying. Now upon completion of the lag phase bacteria will undergo its
next stage referred to as the log phase. This stage involves the generation of
new bacterial cells where the cells double in number by division. This
division occurs by the process of binary fission. Upon fulfilment of the log
phase the third stage will take place. This stage is identified as the stationary
phase. This stage of bacterial growth initiates when the number of cells
which undergo division are equal to the number of cells that die. Therefore
meaning that the growth of bacteria comes to a stationary point. It it also
significant to note that in the duration of this stage the requirement for
nutrients increases and the bacteria become t less active in terms of
metabolic activity and lastly the final stage will proceed. The final stage of
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