Infectious and non-infectious diseases
Introduction
In this assignment I am going to describe the characteristics of the five main types of
pathogens which are: viruses, bacteria, fungus, protozoa and parasites and giving an
example of disease caused by each. I will also be talking about the causations of non-
infectious diseases and then expand further on to explaining the effects of an infectious and
a non-infectious disease on the body and analyse how they evolve over time and the effects
it may have on the infected individuals.
P1 - Explain the characteristics of the five main types of pathogens and a disease
caused by each.
Something that causes a disease is called a pathogen. A disease is a condition that effects
the health of the body including altering its functionality and affecting its overall
performance. They are five main types of pathogens: virus, bacteria, fungus, protozoa and
parasite.
Bacteria
Bacteria are living microorganisms that come in a variety of forms ranging from spirals, rods
and spheres. Some bacteria cause diseases while some are good for the human body.
Bacteria have special characteristics that enables them to survive in a variety of conditions
including outside the human body. (CK-12 Foundation - Jessica Harwood and Douglas
Wilkin,2020)
Bacteria are not visible to naked eye and therefore can only be seen through a microscope
as they are micrometres long in length. They can be recognised and categorised by their
forms or shapes which are three: bacteria that are rode shaped are called bacilli, bacteria
that are sphere like shape are known as cocci and the ones that are spiral shaped are
referred to as spirilla. (CK-12 Foundation - Jessica Harwood and Douglas Wilkin,2020)
As shown by the bacteria image below they have similarities to eukaryotic cells. Bacteria
cells have a fluid like substance called cytoplasm where many chemical reactions occur.
They have cell membrane which functions as a barrier around the cell controlling what goes
in and out of the cell. Bacteria also contain ribosomes which is the site of protein syntheses.
The DNA of the bacteria is protected inside a big circular strand which is found in the
nucleoid found within the cytoplasm. (CK-12 Foundation - Jessica Harwood and Douglas
Wilkin,2020)
Majority of the Bacteria have an extra feature called the plasma which is small ring of DNA
as shown by the image below. They also have a cell wall made up of peptidoglycan (made up
of amino acids and sugars) which is an important feature that surrounds and protects the
bacteria. Some bacteria have a structure known as flagella or a tail that assists the bacteria
with movement as shown by the image below. (CK-12 Foundation - Jessica Harwood and
Douglas Wilkin,2020)
, Bacteria also has a special structure called pili that allows them to attach to the receptors of
other cells allowing them to evade and colonise them. Bacteria lack features like
mitochondria and chloroplasts. Bacteria can cause many different diseases an example
would be Bacterial Pneumonia (inflammation of lungs ) which is caused by Streptococcus
bacteria. (CK-12 Foundation - Jessica Harwood and Douglas Wilkin,2020)
And finally, many bacteria are contagious meaning they can spread from person to person
through direct contact, cough, sneeze and sharing infected materials such as needles with
non-infected person.
Virus
Viruses are microorganisms just like bacteria that can cause diseases and infections. They
are super small and not visible to naked eyes; therefore, a microscope is required to see
them. However, their survival and reproduction are dependent on the cells of other
organisms such as humans due to their inability to store or capture energy. This means they
cannot survive outside its host (not for a long time) which is why scientists considered them
as non-living microorganisms.
Viruses differ in sizes too; they range anywhere from twenty to three-hundred nanometres
and compared to bacteria they are 10 to 100 times smaller in size. This is an advantage for
them as their smaller sizes can allow them to pass through bacteriological filters without
much effort.
The genome (big molecule made up of RNA or DNA) of the virus is found at the core of the
virus and it contains the genetic information for the reproduction of viruses. This genome is
wrapped in a structured called the capsid which is a coat like material consisting of proteins
and its main function is to protect the genetic make-up.
Some versus also has an extra feature made up of lipids called the outer envelope which
protects the capsid and the genome of the virus. Viruses can combine with one another and
mutate and are also resistant to antibiotics. What makes viruses so dangerous is that they
can evade the body for a very long time without causing any negative effects.
Introduction
In this assignment I am going to describe the characteristics of the five main types of
pathogens which are: viruses, bacteria, fungus, protozoa and parasites and giving an
example of disease caused by each. I will also be talking about the causations of non-
infectious diseases and then expand further on to explaining the effects of an infectious and
a non-infectious disease on the body and analyse how they evolve over time and the effects
it may have on the infected individuals.
P1 - Explain the characteristics of the five main types of pathogens and a disease
caused by each.
Something that causes a disease is called a pathogen. A disease is a condition that effects
the health of the body including altering its functionality and affecting its overall
performance. They are five main types of pathogens: virus, bacteria, fungus, protozoa and
parasite.
Bacteria
Bacteria are living microorganisms that come in a variety of forms ranging from spirals, rods
and spheres. Some bacteria cause diseases while some are good for the human body.
Bacteria have special characteristics that enables them to survive in a variety of conditions
including outside the human body. (CK-12 Foundation - Jessica Harwood and Douglas
Wilkin,2020)
Bacteria are not visible to naked eye and therefore can only be seen through a microscope
as they are micrometres long in length. They can be recognised and categorised by their
forms or shapes which are three: bacteria that are rode shaped are called bacilli, bacteria
that are sphere like shape are known as cocci and the ones that are spiral shaped are
referred to as spirilla. (CK-12 Foundation - Jessica Harwood and Douglas Wilkin,2020)
As shown by the bacteria image below they have similarities to eukaryotic cells. Bacteria
cells have a fluid like substance called cytoplasm where many chemical reactions occur.
They have cell membrane which functions as a barrier around the cell controlling what goes
in and out of the cell. Bacteria also contain ribosomes which is the site of protein syntheses.
The DNA of the bacteria is protected inside a big circular strand which is found in the
nucleoid found within the cytoplasm. (CK-12 Foundation - Jessica Harwood and Douglas
Wilkin,2020)
Majority of the Bacteria have an extra feature called the plasma which is small ring of DNA
as shown by the image below. They also have a cell wall made up of peptidoglycan (made up
of amino acids and sugars) which is an important feature that surrounds and protects the
bacteria. Some bacteria have a structure known as flagella or a tail that assists the bacteria
with movement as shown by the image below. (CK-12 Foundation - Jessica Harwood and
Douglas Wilkin,2020)
, Bacteria also has a special structure called pili that allows them to attach to the receptors of
other cells allowing them to evade and colonise them. Bacteria lack features like
mitochondria and chloroplasts. Bacteria can cause many different diseases an example
would be Bacterial Pneumonia (inflammation of lungs ) which is caused by Streptococcus
bacteria. (CK-12 Foundation - Jessica Harwood and Douglas Wilkin,2020)
And finally, many bacteria are contagious meaning they can spread from person to person
through direct contact, cough, sneeze and sharing infected materials such as needles with
non-infected person.
Virus
Viruses are microorganisms just like bacteria that can cause diseases and infections. They
are super small and not visible to naked eyes; therefore, a microscope is required to see
them. However, their survival and reproduction are dependent on the cells of other
organisms such as humans due to their inability to store or capture energy. This means they
cannot survive outside its host (not for a long time) which is why scientists considered them
as non-living microorganisms.
Viruses differ in sizes too; they range anywhere from twenty to three-hundred nanometres
and compared to bacteria they are 10 to 100 times smaller in size. This is an advantage for
them as their smaller sizes can allow them to pass through bacteriological filters without
much effort.
The genome (big molecule made up of RNA or DNA) of the virus is found at the core of the
virus and it contains the genetic information for the reproduction of viruses. This genome is
wrapped in a structured called the capsid which is a coat like material consisting of proteins
and its main function is to protect the genetic make-up.
Some versus also has an extra feature made up of lipids called the outer envelope which
protects the capsid and the genome of the virus. Viruses can combine with one another and
mutate and are also resistant to antibiotics. What makes viruses so dangerous is that they
can evade the body for a very long time without causing any negative effects.
