• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Experiment to investigate the effect of different antibiotics on the bacteria Bacillus subtilis:

Extracts from this document...

Introduction

Experiment to investigate the effect of different antibiotics on the bacteria Bacillus subtilis: Aim: To see which antibiotic (Chloramphenicol, Erythromycin, Fusidic Acid, Oxacillin, Novobiocin, Penicillin, Streptomyan and Tetracycline) reacting with the Bacillus subtilis has the largest zone of inhibition in mm (+/- 0.5mm) and so which has the biggest effect on the bacteria. Introduction: Gram -positive bacteria are bacteria that are dark blue or violet when gram staining. Gram-positive organisms are able to keep the crystal violet stain because of a high amount of peptidoglycan in the cell wall. This makes up about 90% of the thick, more than 20 layers of peptidoglycan together. Gram-positive organisms normally do not have the outer membrane, whereas Gram-negative organisms do. ...read more.

Middle

Antibiotics are produced by microorganisms to kill or control the growth of other organisms. Inappropriate antibacterial treatment and overuse of antibiotics have contributed to the emergence of antibacterial-resistant bacteria. It is important to know that antibiotics only treat bacterial infections, not viral (e.g. common cold) or fungal infections. Variables: -Independent variable: The different antibiotics, which are placed in the Petri dishes with the Bacillus subtilis. C-Chloramphenicol, 25ug E- Erythromycin, 5ug FE-Fluidic Acid, 10ug OX-Oxacillin, 5ug NO- Novobiocin, 5ug, PG- Penecillin G, 1 unit S- Streptomyan, 10 ug T- Tetracyline, 25ug -Dependent variable: The zone of inhibition (of killed bacteria) in mm (+/- 0.5mm). Measured with a ruler. Results: The following is a table to show how large the zone of inhibition for each antibiotic is in mm. ...read more.

Conclusion

The zone of inhibition for these antibiotics is the largest. The different types of penicillin show very similar results in all five repeats and P1 has the smallest zone of inhibition, whereas P10 has the largest. Overall the table shows that Oxacillin has the largest average zone of inhibition with 22.6 mm. Looking at the table carefully the size of the zone of inhibition increases steadily from an average of 13.4mm until it reaches Oxacillin at an average of 22.6mm and then it decreases again. Only Tetracycline has a higher size of the zone of inhibition again. This shows that different antibiotics have differently strong effects on the same bacteria. Therefore it must be considered well which antibiotics to take against which infection. Biology-Miss Hardy By Rebecca Kriegbaum ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Here's what a teacher thought of this essay

4 star(s)

****

A very good, interesting scientific study.

Although not complete the foundation for an excellent investigation is present.

The method needs to be provided which would allow the reader to repeat the experiment. The data collection is excellent and answers the aim of the investigation well.

The conclusion does not put enough emphasis on the central question of which antibiotic is most effective and offer a scientific explanation of why this might be.

Marked by teacher Jon Borrell 22/05/2013

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Biology essays

  1. Marked by a teacher

    The effect of Pectinase Concentraton on the production of apple juice

    Excessive alkalinity and acidity may also denature enzymes so keeping a constant pH will make sure that this will not happen. * Temperature - Different enzymes work better in different temperatures as they have their optimum temperatures that allow them to react at different rates.

  2. To investigate how aerobic exercise affects the heart rate

    Press the start button and remain still 7. The cuff will inflate and numbers will be displayed 8. When the measurement is complete, the cuff will deflate 9. The blood pressure and pulse rate will be displayed on the screen Range and repetitions of experiment Range The range of my experiment is from 0 minutes to 5 minutes.

  1. Vitamin C concentration

    Type of solution Average number of drops [�1] Volume [�0.05] Ascorbic acid 8 0.55 Lemon 14 1.00 Old lemon 25 1.80 Tomato 48 3.45 Orange 36 2.55 Rutinoscorbin 14 1.00 Orange juice 18 1.30 Tomato juice 89 6.35 The concentration of vitamin C in the samples was calculated using the

  2. To investigate the amount of protein present in different types of milk by measuring ...

    The mean is calculated with the AVERAGE function Ex: Calculate the mean of the values in skimmed milk B5 to H5 fx = AVERAGE (B5:H5) - For standard deviation use the STDEVA function Ex: Calculate the standard deviation of the values in skimmed milk B5 to H5 fx = STDEVA (B5:H5)

  1. Determine the energy content of different types of Seed: Compare the calorie content of ...

    Another dependant variable is the mass (g) of each type of seed, which was 2g, we measured it using weighing scales, and this variable was controlled because if the mass of seed varied then the energy content would be directly affected.

  2. Biology Lab Report - Effects of Mouthwash on Oral Bacteria

    1. Purpose This experiment aims to find out the effectiveness of mouthwash against oral bacteria. 2. Hypothesis Mouthwash C: Listerine-Cool Mint is the most effective mouthwash at inhibiting the growth of oral bacteria. 3. Variables Independent Variables: 1. Types of mouthwash Control Variables: 1.

  1. Experiment-Effect of Temperature on the Action of Amylase Enzyme

    Place each of the test tubes in separate water baths for 5 minutes. Allow the temperature of each of the amylase solutions to come to equilibrium with that of the water bath. 4. Mix the solution with clean glass rod. Continue to monitor the temperature.

  2. Investigating the Effects of Salt on Seed Germination

    of each petri dish and ensure that there is 1cm gap between them. * The same conditions present around the experiment (room temperature, sunlight, disturbance, humidity, etc.). To keep the room temperature and sunlight consistent for each petri dish, we will place each petri dish next to each other at the same location.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work