Aim:
I want to investigate how different disinfectant concentrations can affect the reproduction and growth
of micro-organisms, bacteria.
I want to investigate how different disinfectant concentrations can affect the reproduction and growth
of micro-organisms, bacteria.
Hypothesis:
My hypothesis is, the more concentrated the dettol the more bacteria it will kill.
My hypothesis is, the more concentrated the dettol, the more bacteria that will die, meaning a larger
clear zone.
clear zone.
Variables:
Independent Variables:
The variable that I will be changing is the concentration of the disinfectant I will do this by adding the
same amount of disinfectant to different amounts of water to change its strength.
I will use:
The variable that I will be changing is the concentration of the disinfectant I will do this by adding the
same amount of disinfectant to different amounts of water to change its strength.
I will use:
- Full strength dettol
- Manufacturers instructions
- No dettol - just water
- Diluted dettol
Dependent Variable:
The variable that I will measure is the size of the clear zone around the Dettol disk.
The variable that I will measure is the size of the clear zone around the Dettol disk.
I will measure the diameter of the clear zone by using a ruler.
Other variables:
Other variables that can change the outcome of the experiment are:
- Growing temperature - we need to grow bacteria in the same temperature for each.
- Same environment - We need to grow the bacteria on the same medium (Seaweed jelly)
- Growing time - We need to grow the bacteria for the same amount of time.
- Size of the disc - we need to make sure we have the same amount of dettol .
- The age of the dettol, the length of time the seal has been broken i.e. shelf life
Reliability
To ensure reliability I will repeat the experiment three times.
Method:
Step 1
Gather the equipment
Gather the equipment
- Dettol
- Vivid - for labeling
- Filter paper
- Water
- Salatape
- Agar plate
- Hole punch
- Bacterial solution, a solution of bacteria
- Pipette
- Tweezers
Step 2
Get the filter paper and cut out 4 disks with the hole punch.
Get the filter paper and cut out 4 disks with the hole punch.
Step 3
Using your vivid, mark out the agar plate into four quadrants (sections), label each quadrant so you can identify which section is which, do not label the lid, label the bottom of the agar plate.
Step 4
Using the pipette transfer some of the bacteria solution onto the agar plate.
Swirl the bacteria around in the agar plate, with the lid on, to cover all the surface.
Swirl the bacteria around in the agar plate, with the lid on, to cover all the surface.
Step 5
Tip out the excess bacteria solution in the agar plate into a sink, do NOT rinse agar plate.
Tip out the excess bacteria solution in the agar plate into a sink, do NOT rinse agar plate.
Step 6
Using the tweezers, pick up the disc and dip them into the water, shake off any excess drops, and a
place it into the appropriate quarter.
place it into the appropriate quarter.
Step 7
Using the tweezers, pick up the second disc and dip them into the dettol, shake off any excess drops and place it into the appropriate quarter.
Using the tweezers, pick up the second disc and dip them into the dettol, shake off any excess drops and place it into the appropriate quarter.
Step 8
Make up the next solution in a measuring cylinder, put 400 ml of water in the cylinder and one cap full of dettol. Mix together and pick up the third disc, dip them into the watery dettol, shake off excess drops and place into the appropriate agar plate quadrant
Make up the next solution in a measuring cylinder, put 400 ml of water in the cylinder and one cap full of dettol. Mix together and pick up the third disc, dip them into the watery dettol, shake off excess drops and place into the appropriate agar plate quadrant
Step 9
Make up the last solution in a measuring cylinder, put 800 ml of water into the cylinder and one cap full of dettol. Swirl to mix together and pick up the third disc, dip them into the watery dettol, shake off excess drops and place into the agar plate quadrant
Make up the last solution in a measuring cylinder, put 800 ml of water into the cylinder and one cap full of dettol. Swirl to mix together and pick up the third disc, dip them into the watery dettol, shake off excess drops and place into the agar plate quadrant
Step 10
Name the side of the lid and tape the lid onto the agar plate.
Step 11
Incubate at 20 degrees, upside down. Leave it over the weekend and come back tuesday!
Incubate at 20 degrees, upside down. Leave it over the weekend and come back tuesday!
Step 12
Repeat 2 more times so you have 3 results.
Repeat 2 more times so you have 3 results.
What happened?
During our test, bacteria was able to grow in the environment given. But due to the dettol, bacteria was killed off, the clear zone increased with the larger amounts of concentrated dettol added.
During our test, bacteria was able to grow in the environment given. But due to the dettol, bacteria was killed off, the clear zone increased with the larger amounts of concentrated dettol added.
How does this happen?
During the process, dettol seeps into the bacteria and breaks down the cell wall, seeping right into the cytoplasm. The chemical in dettol, Chloroxylenol, stops the bacteria from producing ATP (produced by proton gradient distributor), Adenosine TriPhosphate or ATriPhosphate. ATP is the energy storer, it responds to the bodies need for energy, i.e. moving, breaking, or eating, this stops the bacteria from reproducing and gathering nutrition, promptly starving the bacteria to death. The ATP’s are produced by proton gradient distributor, by shutting this down ATP can not be produced.
The enzymes within bacteria gets shut down, the particular enzymes that are able to degrade down nutrients, organic materials, such as fats, oils, cellulose (an organic compound with multiple linked glucose units), xylan (found within plant cell walls and some algaes), proteins, and starches, are shut down due to the chloroxylenol within dettol. This will also stop the bacteria from being able to gather nutrients, again, promptly starving the bacteria to death.
During the process, dettol seeps into the bacteria and breaks down the cell wall, seeping right into the cytoplasm. The chemical in dettol, Chloroxylenol, stops the bacteria from producing ATP (produced by proton gradient distributor), Adenosine TriPhosphate or ATriPhosphate. ATP is the energy storer, it responds to the bodies need for energy, i.e. moving, breaking, or eating, this stops the bacteria from reproducing and gathering nutrition, promptly starving the bacteria to death. The ATP’s are produced by proton gradient distributor, by shutting this down ATP can not be produced.
The enzymes within bacteria gets shut down, the particular enzymes that are able to degrade down nutrients, organic materials, such as fats, oils, cellulose (an organic compound with multiple linked glucose units), xylan (found within plant cell walls and some algaes), proteins, and starches, are shut down due to the chloroxylenol within dettol. This will also stop the bacteria from being able to gather nutrients, again, promptly starving the bacteria to death.
What chemical in dettol kills the bacteria?
The chemical in dettol that kills bacteria is called Chloroxylenol, what is also known as
para-chloro-meta-xylenol, and antiseptic chemical used to disinfect skin, cleaning surgical instruments
and surfaces. Chloroxylenol contains the chemicals C8, H9 and CIO.
Chloroxylenol is not toxic to humans, non toxic to birds and is moderately toxic to freshwater invertebrates (Animals that do not possess vertebrate columns (Spine)). The chemical is known to be dangerous to cats, and is extremely lethal to the cane toad. The chemical was banned from being used as pest control in western Australia due to concerns of flora and fauna potentially being harmed.
Chloroxylenol is not toxic to humans, non toxic to birds and is moderately toxic to freshwater invertebrates (Animals that do not possess vertebrate columns (Spine)). The chemical is known to be dangerous to cats, and is extremely lethal to the cane toad. The chemical was banned from being used as pest control in western Australia due to concerns of flora and fauna potentially being harmed.
What is a cell wall?
A cell wall is a structural layer that some cells have, the bacteria we studied, a typical gram positive
bacterium, has this layer. In this bacteria, the cell wall resides underneath capsule, the outer layer.
The cell wall is what bacteria uses as protection, it being a key part of its survival. It provides the
bacteria structure, it also stops water from rushing into the bacteria and disrupting the large amounts
of protein they contain. The thickness of a cell wall can help identify weather the bacteria is gram
positive (Thicker cell wall, dettol being more effective on this type) or gram negative (Thinner cell wall,
dettol being less effective on this type), identification of this is called Gram Staining.
The cell wall is what bacteria uses as protection, it being a key part of its survival. It provides the
bacteria structure, it also stops water from rushing into the bacteria and disrupting the large amounts
of protein they contain. The thickness of a cell wall can help identify weather the bacteria is gram
positive (Thicker cell wall, dettol being more effective on this type) or gram negative (Thinner cell wall,
dettol being less effective on this type), identification of this is called Gram Staining.
The cell wall protects the bacteria, it determines what goes in at what goes out of the bacteria.
Although this effective, bacteria cell walls have holes in it, these holes are what allowed dettol to enter
the bacteria's system.
Although this effective, bacteria cell walls have holes in it, these holes are what allowed dettol to enter
the bacteria's system.
Capsule
The cell capsule is a well organised layer, the layer is the resides above the others. It is the cause of
various diseases, such as salmonella, this is done by enhancing the ability to create and spread the
diseases. The capsule is found in both gram negative and gram positive bacteria.
various diseases, such as salmonella, this is done by enhancing the ability to create and spread the
diseases. The capsule is found in both gram negative and gram positive bacteria.
The cell capsule is a well organised layer, the layer is the resides above the others. It is the cause of
various diseases, such as salmonella. The capsule is found in both gram negative and gram positive
bacteria.
various diseases, such as salmonella. The capsule is found in both gram negative and gram positive
bacteria.
The capsule can protect the cell from engulfment by eukaryotic cells (A type of cell with a nucleus
enclosed within membranes)
enclosed within membranes)
The capsule is made up of polysaccharide, a carbohydrate with molecules consisting of a number of
sugar molecules bonded together. The background, surface, that the bacteria resides on is stained
darker than the bacteria. The capsule is the light, either pale or colorless, residing as the outer layer
like a halo or ring.
sugar molecules bonded together. The background, surface, that the bacteria resides on is stained
darker than the bacteria. The capsule is the light, either pale or colorless, residing as the outer layer
like a halo or ring.
Cell wall
A cell wall is a structural layer that some cells have, the bacteria we studied, a typical gram positive
bacterium, has this layer. In this bacteria, the cell wall resides underneath capsule, the outer layer.
The cell wall is what bacteria uses as protection, it being a key part of its survival. It provides the
bacteria structure, it also stops water from rushing into the bacteria and disrupting the large amounts
of protein they contain. The thickness of a cell wall can help identify weather the bacteria is gram
positive (Thicker cell wall, dettol being more effective on this type) or gram negative (Thinner cell wall,
dettol being less effective on this type), identification of this is called Gram Staining.
bacterium, has this layer. In this bacteria, the cell wall resides underneath capsule, the outer layer.
The cell wall is what bacteria uses as protection, it being a key part of its survival. It provides the
bacteria structure, it also stops water from rushing into the bacteria and disrupting the large amounts
of protein they contain. The thickness of a cell wall can help identify weather the bacteria is gram
positive (Thicker cell wall, dettol being more effective on this type) or gram negative (Thinner cell wall,
dettol being less effective on this type), identification of this is called Gram Staining.
The cell wall protects the bacteria, it determines what goes in at what goes out of the bacteria.
Although this is effective, bacteria cell walls have holes in it, these holes are what allowed dettol to
enter the bateria’s system.
Although this is effective, bacteria cell walls have holes in it, these holes are what allowed dettol to
enter the bateria’s system.
Plasma Membrane
The plasma membrane regulates the movement of substances moving into and out of the cell,
maintaining the cell structure, holding proteins and linking together tissues and cellular components.
The cellular components provide hydrophilic signals, a molecule that has a better reaction with water
and other polar substances, than the reaction with oil or other solvents. The membrane contains
proteins which transport protein makers and salt in and out, which help other proteins attach and act
as a identifier for the bacteria. This helps the membrane communicate with each other.
maintaining the cell structure, holding proteins and linking together tissues and cellular components.
The cellular components provide hydrophilic signals, a molecule that has a better reaction with water
and other polar substances, than the reaction with oil or other solvents. The membrane contains
proteins which transport protein makers and salt in and out, which help other proteins attach and act
as a identifier for the bacteria. This helps the membrane communicate with each other.
Cytoplasm
Cytoplasm is made up of mostly water and salt. It is present beneath the plasma membrane and is a
jelly like fluid.
jelly like fluid.
The cytoplasm holds enzymes, this part of the bacteria is also responsible for breaking down waste
and aiding in metabolic activity (The life sustaining chemical transformation within cells)
and aiding in metabolic activity (The life sustaining chemical transformation within cells)
Cytoplasm helps form the shape of the bacteria, it fills the inside with a jelly like fluid making the
bacteria have a more solid form.
bacteria have a more solid form.
Ribosome
The ribosome function is as a form of workbench, it it translates the genetic instructions for the
formation of specific proteins, they are the cellular component that makes proteins from amino acids.
Ribosomes are made up of RNA, ribonucleic acid, RNA is a molecule essential in coding, decoding,
regulation and expression of genes. RNA is almost identical to DNA, but RNA is made of ribose sugar
instead of deoxyribose sugar and have nucleotides with a uracil base instead of thymine.
formation of specific proteins, they are the cellular component that makes proteins from amino acids.
Ribosomes are made up of RNA, ribonucleic acid, RNA is a molecule essential in coding, decoding,
regulation and expression of genes. RNA is almost identical to DNA, but RNA is made of ribose sugar
instead of deoxyribose sugar and have nucleotides with a uracil base instead of thymine.
Plasmid
Plasmid is a small DNA molecule within the cell that is physically separated from the bacterial DNA,
this can be replicated independently. When a bacteria is under stress, the plasmid helps keep them
alive longer, this gives the bacteria a better opportunity to reproduce and pass the plasmid onto their
daughter cells.
this can be replicated independently. When a bacteria is under stress, the plasmid helps keep them
alive longer, this gives the bacteria a better opportunity to reproduce and pass the plasmid onto their
daughter cells.
The form of plasmid is usually as a small, circular, double stranded DNA molecule, the genes carried
by plasmid provide bacteria with genetic advantages, such as a resistance to antibiotics.
by plasmid provide bacteria with genetic advantages, such as a resistance to antibiotics.
Pili
The pili are like small hairs, they enable some pathogens to attach and adhere (Stick fast) easily to
cell surface. The pili are shorter, straighter and more numerous than the flagella and are composed by
subunits of protein.
cell surface. The pili are shorter, straighter and more numerous than the flagella and are composed by
subunits of protein.
The main function of the pili is to attach the bacteria to surfaces and other cells. The pill also aid in the
attachment between bacteria.
attachment between bacteria.
Flagellum
The flagellum is a long hair like surface. It allows the bacteria to move and will span from 0.1 to 50
micrometers in diameters, averaging to around 2 micrometers.
micrometers in diameters, averaging to around 2 micrometers.
It is seen in three types of organisms, bacteria, archaea, and eukarya, yypes of single cell organisms.
The flagellum are used for locomotion, the three types of organisms have different flagellar structures.
Many different types of bacteria have flagella, consisting of: Monotrichous, Amphitrichous and
Peritrichous.
Peritrichous.
The flagellum has three parts, the filament, the hook and the basal body. The filament is a rigid helical
structure.
structure.
The hook is a flexible coupling, residing between the filament and basal body.
The basal body consists of a rod, a series of rings, these rings provide as an anchor for the flagellum
to the cell wall.
to the cell wall.
Binary Fission
Bacterial reproduction
Binary fission, division in half, is an asexul process. It is the most common form of reproduction,
occurring in a variety of organisms, such as bacteria.
occurring in a variety of organisms, such as bacteria.
During the process DNA and segregation occur simultaneously. The parent cell splits into two halves.
First it replicates its DNA, elongates, splits and produces two equal daughter cells.
First it replicates its DNA, elongates, splits and produces two equal daughter cells.
These cells are genetically identical, there are few occurrences of identical in daughter cells, this
occurs because of mutations present during binary fission.
occurs because of mutations present during binary fission.
Binary fission takes around 20 minutes to complete. Accurate timing for each step would be almost
impossible due to bacteria taking random times for each step, approximately adding up to around
20 minutes.
impossible due to bacteria taking random times for each step, approximately adding up to around
20 minutes.
Diffusion
Diffusion within bacteria works with bacterial transportation systems.The bacteria transport systems are
operated by proteins, more specifically transport proteins, these proteins reside within the plasma
membrane, these proteins and plasma membrane act as a sponge, taking in nutrients in large numbers
to keep the bacteria energized and healthy.
operated by proteins, more specifically transport proteins, these proteins reside within the plasma
membrane, these proteins and plasma membrane act as a sponge, taking in nutrients in large numbers
to keep the bacteria energized and healthy.
Solutes (a minor component of a solution) are what bacteria use for nutrients, these solutes are
transported through the membrane by the transport systems, the transport systems have three ways to
transport the nutrients through.
transported through the membrane by the transport systems, the transport systems have three ways to
transport the nutrients through.
The first is Uniport, uniport is where one solute will go through the the membrane in a straight/non-indirect
line.
line.
The second process is Symport, symport is where two solutes are transported at the same time through
the membrane in the same direction.
the membrane in the same direction.
The last process is Antiport, antiport is where two solutes are being transported at the same time, one
solute is transported into the bacteria, while the other is transported out, simultaneously.
solute is transported into the bacteria, while the other is transported out, simultaneously.
The solutes consist of carbons, such as sugars, fats, and amino acids. The plasma membrane lets these solutes in, but the enzymes are what breaks down the complex compounds to use the nutrients.
Plate 1
|
Plate 2
|
Plate 3
|
Plate 4
|
Average
| ||
Full Strength
|
30 mm
|
25 mm
|
30 mm
|
30 mm
|
31.67
| |
Manufactures Instructions
|
25 mm
|
10 mm
|
30 mm
|
30 mm
|
18.33
| |
Diluted
|
0 mm
|
10 mm
|
25 mm
|
25 mm
|
10.32
| |
Water
|
0 mm
|
0 mm
|
0 mm
|
0 mm
|
0
| |
Plate 4 is an unbelievable results. Full strength dettol would kill more
than the manufacturer's instructions. I am ruling this plate out as untrue. The reasons it could have been messed up is because of the tweezers used, the examiners mostlikely didn't rinse the tweezers before taking a sample of the manufacturers instructions and therefore left the disk with pure dettol on it. This can cause more bacteria to die and result in a larger clear zone, as seen in the results. |
As seen in the trend the disinfectant strength increased the clear zone, as I wanted to investigate the different strength of the dettol killed off at different rates micro-organisms, the higher concentration of dettol proved to be effect in this, but because of bacteria being set to die as soon as the dettol sets in it would be a waste to use a higher concentration of dettol on a larger surface.
Evaluation
During this investigation I found that the stronger the dettol was the larger the clear zone would be.
But, if I were to use undiluted dettol on a tile floor it would be a waste of dettol, the moment dettol
seeps into the bacterias system the bacteria is set to die, using the diluted dettol will kill off bacteria
effectively and will not waste any dettol.
But, if I were to use undiluted dettol on a tile floor it would be a waste of dettol, the moment dettol
seeps into the bacterias system the bacteria is set to die, using the diluted dettol will kill off bacteria
effectively and will not waste any dettol.
This investigation was fair due to having five different results, four with similar results and one with an
odd result, this result was left out of the graph. All instructions were followed correctly to get the best
results in the experiment giving a more accurate result. Our results were off due to the agar plate not
being placed in the incubation chamber straight away, this proved difficult for my results but due to
having other results to work with I could work out the information needed.
odd result, this result was left out of the graph. All instructions were followed correctly to get the best
results in the experiment giving a more accurate result. Our results were off due to the agar plate not
being placed in the incubation chamber straight away, this proved difficult for my results but due to
having other results to work with I could work out the information needed.
This is my results, as you can see the bacteria did not grow properly to get the information needed to
calculate my results.
calculate my results.
This is one of the more accurate result I used, as you can see the bacteria grew well and more
accurately when killed off. This provided good information to help calculate the information needed for
my results.
Here are the other results I used
accurately when killed off. This provided good information to help calculate the information needed for
my results.
Here are the other results I used
Perfluorinated: a chemical that contains carbon-fluorine bonds. Used in teflon, water resistance textiles
and fire-fighting foam. This chemical is a Heteroatoms, a compound of 3 chemicals.
and fire-fighting foam. This chemical is a Heteroatoms, a compound of 3 chemicals.
Carboxylic: An organic compound of 3, O, R, and OH. It occurs widely within the body, the acid
includes amino acids, the acid that creates protein, usually occurring within blood and tissue.
Note -
I worked with Kimberly during this experiment
http://hhskimberleym.blogspot.com/
includes amino acids, the acid that creates protein, usually occurring within blood and tissue.
Note -
I worked with Kimberly during this experiment
http://hhskimberleym.blogspot.com/
