Purpose: How the concentration can effect the rate in killing bacteria
What is Bacteria: Bacteria is a micro-organism. Bacteria is known to be one of the first life forms on earth and in the soil
What is the life process if bacteria? MRS GREN - Movement, Reproduction, Sensitivity, Growth, Respiration, Excretion and Nutrition
How does disinfectant work? Disinfectants kill bacteria extremely fast when they come into contact It works on living things a swell as non living things
What is savlon? Savlon is an antiseptic that is used to kill bacteria, you can put savlon on cuts to clean the injury from any bacteria
What is the active ingredient in savlon? It is called cetrimide. It is a mixture of different kinds of ammonium salts. When it comes into contact with bacteria it disrupts the cell wall on the bacteria which stops the function of enzymes in the nucleoid. Savlon also kills bacteria within 15 seconds
Trial Experiment
Aim: I want to investigate how the concentration of dettol effects the growth and reproduction of bacteria
Hypothesis: I predict that the higher the concentration of dettol will create a large clear zone in the agar plate
Independent variable: Concentration of dettol, 1% 10% 100% and control (just water)
Dependent variable: The inside of the clear zone (mm)
Equipment:
- Agar plate
- Dettol
- Yogurt
- Filter paper
- Marker
- Ruler
- Ethanol
- Dropper
- Spotting tile
- Cotton bud
- Tweezers
- Cellotape
Method:
1. Get Equipment
2. Use the marker to divide the agar plate into 4 sections (on jelly side) In each section label the different concentrations of dettol
3. Get the cotton bud and smear the yogurt onto the jelly on the agar plate
4. (make sure dropper is always clean so there is no contamination) Using a dropper put a few drops of dettol into the spotting tile (100% concentration) Add 1 drop of dettol onto another spotting tile than add 9 drops of water (10% concentration) then take the 10% concentration and add some of that to 9 drops of water on the spotting tile (1% concentration)
5. Use a whole punch to punch 4 holes out of the filter paper (circles must be the same)
6. Dip ends of tweezers in ethanol and run it through the Bunsen burner to sterilize them
7. Using the tweezers now pick up the filter paper and dip each paper into a different concentration and then blot the filter paper do their is no excess concentration and put onto agar plate under the right label
8. Put cello-tape around the edges to close the agar plate and wait for the bacteria to grow
9. Leave overnight and measure clear zone.
Equipment
- Savlon
Equipment:
- Agar plate
- Dettol
- Yogurt
- Filter paper
- Marker
- Ruler
- Ethanol
- Dropper
- Spotting tile
- Cotton bud
- Tweezers
- Cellotape
Method:
1. Get Equipment
2. Use the marker to divide the agar plate into 4 sections (on jelly side) In each section label the different concentrations of dettol
3. Get the cotton bud and smear the yogurt onto the jelly on the agar plate
4. (make sure dropper is always clean so there is no contamination) Using a dropper put a few drops of dettol into the spotting tile (100% concentration) Add 1 drop of dettol onto another spotting tile than add 9 drops of water (10% concentration) then take the 10% concentration and add some of that to 9 drops of water on the spotting tile (1% concentration)
5. Use a whole punch to punch 4 holes out of the filter paper (circles must be the same)
6. Dip ends of tweezers in ethanol and run it through the Bunsen burner to sterilize them
7. Using the tweezers now pick up the filter paper and dip each paper into a different concentration and then blot the filter paper do their is no excess concentration and put onto agar plate under the right label
8. Put cello-tape around the edges to close the agar plate and wait for the bacteria to grow
9. Leave overnight and measure clear zone.
Equipment
- Savlon
- Agar plate
- Beaker
- Marker
- Filter paper
- Whole punch
- Tweezers
- Yogurt
- Dropper
- Ethanol
- Paper towel
- Ruler
- Spotting tile
- Cello-tape
- Ethanol
- Paper towel
- Ruler
- Spotting tile
- Cello-tape
Method:
1. Get your equipment.
2. Start by using a permanent marker (on the jelly side) to divide the agar plate into 4 sections. In each section label them with the different concentrations of Savlon. (eg. 100%, 10%, 1% and water)
3. Get a beaker and add the yogurt. Then put some water into the beaker to dilute it, which will make the yogurt more of a runnier texture. This will make it easier for you to just pour it onto the agar plate and move it around so the whole surface is covered, and you can get a clear look at the bacteria.
4. Using a dropper, put a few drops of Savlon into a spotting tile. This is the concentration of 100%, and again using the dropper put 1 drop of the Savlon into a separate tile. Then this time add 9 drops of water to equal a concentration of 10%. Repeat this step again by taking a drop of the 10% concentration, to then create a concentration of 1%. (Make sure the dropper is always clean so there is no contamination)
5. Then punch 4 full circles into the filter paper using a hole punch. (If the circles aren't the same the test won't be fair)
6. Dip tweezers in ethanol and then but through the Bunsen burner to sterilize them
F
7. Get some tweezers and dip the filter paper into the different concentrations. Blot the filter paper onto a paper towel to get rid of any excess. Then put them onto the agar plate in the right percentages
2. Start by using a permanent marker (on the jelly side) to divide the agar plate into 4 sections. In each section label them with the different concentrations of Savlon. (eg. 100%, 10%, 1% and water)
4. Using a dropper, put a few drops of Savlon into a spotting tile. This is the concentration of 100%, and again using the dropper put 1 drop of the Savlon into a separate tile. Then this time add 9 drops of water to equal a concentration of 10%. Repeat this step again by taking a drop of the 10% concentration, to then create a concentration of 1%. (Make sure the dropper is always clean so there is no contamination)
5. Then punch 4 full circles into the filter paper using a hole punch. (If the circles aren't the same the test won't be fair)
6. Dip tweezers in ethanol and then but through the Bunsen burner to sterilize them
F
7. Get some tweezers and dip the filter paper into the different concentrations. Blot the filter paper onto a paper towel to get rid of any excess. Then put them onto the agar plate in the right percentages
8. Put cello tape around the agar plate and wait for the bacteria to grow
9. Measure the clear zones on the agar plates
10. Repeat if needed
*graph at bottom*
Conclusion
Conclusion
The aim of this experiment was to investigate how different concentrations of savlon can effect the growth and reproduction of bacteria. I predicted that the larger the concentration of savlon there was that then the larger the clear zones were. After looking at my data i can see that there is an increasing trend. If you increase the concentration of bacteria then the larger the clear zone will be.
Discussion
What is disinfectant? Disinfectant is liquid the you can apply to the surface of non-living things and living things to kill good and bad bacteria rapidly when in contact. Antiseptic is used on skin, it is made so that it kills bacteria in cut but yet it won't hurt. There are wide ranges of substances which are used as disinfectant including alcohols. Disinfectant works in different ways, Hydrogen peroxide reacts to produce free oxygen radicals and bleaches. They are based on chlorine compounds which are very powerful oxidising agents. They oxidise the complete molecules which are present on the surface of bacteria, causing their cell membranes to disrupt. Proteins on the surface become damaged and they then start to stick together in clumps. Bacteria cannot respond to the damage quickly enough and the whole cell splits open and dies.
The structure of bacteria: Reproduction of bacteria:
Capsule - Protective outer layer
Cell wall - Structure to give shape and protect it aswell
Ribosomes - Build protein for the cell
Plasmid - Extra bits of DNA
Cell membrane - Nutrition and excretion (lets food in and lets waste out)
Pili - Bridge to other bacteria
Flagellum - Used for movement
Cytoplasm - The soup of the cell that holds the DNA, ribosomes, plasmids but it mostly holds water
Nucleoid - Holds DNA for essential life
URL: https://www.thoughtco.com/bacterial-reproduction-373273
http://www.thebigger.com/biology/monera/explain-the-nutrition-system-in-bacteria/
Reproduction and Nutrition of bacteria:
Reproduction (binary fission)
During their asexual reproduction a single DNA replicates and both copies attach, at a different point on the bacteria. As the cells begin to get bigger and join the distance between the DNA molecules begin to increase. Once the bacteria doubles in size the cell membrane begins to pinch in the centre, Then a cell wall forms which ends up separating the two cells. That original cell is now two identical daughter cells.
Nutrition
Bacteria are autotrophs or heterotrophs but most are autotrophs, The autotrophs make their own food from outside sources of energy. Heterotrophs don't make their own food, they rely on readymade food from outside to be able to survive
Evaluation
The data I created wasn't as reliable as it should've been to use and measure. We ended up having 3 valid results although it could have been better. We almost had to redo our experiment due to using too much yogurt on the agar plates. We were able to fix this due to the fact that the bacteria did grow and left some clear zones. Which we were able to work with and measure the other clear zone that occurred. The other clear zones that didn't work to well we were able to estimate where the clear zone and draw a circles around it with the marker. We did this to make it easier to measure and easier to find the results
Hi Jordana,
ReplyDeleteI appreciate that you added photos to your post - great thinking! Make sure you check everything off as you go. Specifically what are your dependent and independent variables?
Miss Huddleston