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

Investigating the Effect of Sodium Fluoride on Respiration in Yeast

Extracts from this document...

Introduction

Biology IA The Effect of Sodium Fluoride on Respiration in Yeast 2013 Design Research Question Does changing the amount of Sodium Fluoride effect the rate of respiration as measured by the colour change of resazurine? Variables Independent Variable Different amounts of sodium chloride 0,5,10,15 and 20mL Dependant Variable Rate of production of H+ ions as measured by the colour change of resazurine, the degree of colour change shall be measured on the gradient below using the assigned numerical value to the colour. Results Raw Data Table showing the effect different volumes of Sodium Fluoride has on the rate of production of H+ ions as measured by the colour change of resazurine Amount of Sodium Fluoride ±1 Colour change assigned a numerical value from the above gradient Observations Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 0 1 1 1 1 - Large colour change, froth 5 2 2 3 2 - Large colour change, bubbles 10 2 3 4 3 - Colour change, bubbles, layers 15 3 ...read more.

Middle

This indicates that sodium fluoride is an inhibitor of respiration, the scientific theory behind by results is explained below. During respiration glucose is oxidised and hydrogen released at various stages, controlled by a dehydrogenase enzyme. In our experiment we used yeast, a microscopic, unicellular organism as a respiratory substrate as it contains stored food. To measure the rate of respiration we used resazurine as changes colour when it is reduced (gains H2), which occurs during respiration. The lighter the final colour the larger the amount of respiration, or according to our colour gradient the small number equates to a higher rate of respiration. In the yeast an enzyme enolase catalyzes the conversion of phosphoglycerate into phosphoenol pyruvate. Yet this conversion can be inhibited by the introduction of sodium fluoride as it is an inhibitor of the enzyme "enolase" an enzyme necessary for glycolysis(2). Therefore as we increased the volume of sodium fluoride added to the yeast less colour change will occur as the sodium fluoride is precenting glycolysis and the subsequent production of H2 ions which react with the resazurine causing it to change colour. ...read more.

Conclusion

Because the reaction is effected by light there would have differing light levels between trials causing there to be different respiration rates effecting the validity and reliability of our results. Conduct the experiment in pitch black with one lamp 30cm away for the test tube and have an automated device which measures the amount of light let through the test tube. Temperature of the water bath was difficult to maintain. As respiration is enzyme controlled and enzymes are effected by temperature it is important to keep the temperature consistent. Otherwise decreases in temperature will cause the enzymes kinetic energy to decrease and less collisions will be made and the rate of respiration will decrease. Which will significantly decrease the validity of our results. We could use an electronic thermostatic water bath. Which would keep the temperature consistent. Low concentration of sodium Fluoride Because we were using a low concentration we were not getting differences between our results. Therefore the conclusion was difficult as out results were clustered together. Use a 0.5 mol/dm3 of sodium fluoride. 1http://www.courseworkbank.info/courseworkbank.info.php?f=R0NFIEEgLSBMZXZlbC9DaGVtaXN0cnkvUmF0ZSBvZiByZXNhenVyaW4gZWNwZXJpbWVudC5wZGY= 2http://www.faculty.fairfield.edu/genbio/lab171/LabManual1_201201.pdf ...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

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. IB biology Respiration IA

    36.73 28.59 26.26 Jumping Jacks 10.0 1 30 6 25.21 29.08 15.55 Jumping Jacks 10.0 1 30 7 31.07 17.50 14.22 Jumping Jacks 10.0 1 30 8 32.28 28.68 19.03 Jumping Jacks 10.0 1 30 9 35.16* 23.46* 23.83* Jumping Jacks 10.0 1 30 10 34.29 32.47 21.17 Jumping Jacks

  2. The effect of the tempereature on yeast metabolism.

    Also, as it will take longer for the temperature inside the test tube the same as the water bath, I will leave them to equilibrate for 5 minutes and then mix the solutions together (glucose-yeast and TTC a redox indicator.)

  1. The effect of toliet cleaning products on E-coli ...

    -Keep container tightly closed. -In case of contact with eyes rinse with plenty of water and contact Doctor or Poisons Information Centre. R18 R36 R52 R67 S22 S24 S39 S51 S49 S40 S07 S26 Methylated spirits -Highly flammable. - Irritating to eyes.

  2. In this extended essay I am looking at the effect of different kind of ...

    is covered too deeply within the soil or the soil is covered with a lot of water then the seed can starve for the oxygen which can result in the death of the embryo. Several seeds have water-resistant seed coats that stop oxygen from entering the seed, causing a sort

  1. Testing the effect of characteristics of leaves on the transpiration rate of * ...

    � water � a clamp stand � 2 x clamps � stopwatch � a 30cm ruler (� 0.1 cm) � sheets of squared paper (1cm grid) � a calculator Method 1. Cut four different kinds of branch of plants using secateurs *Make sure the thickness of the branches fits well to the rubbing tube of a potometer 2.

  2. How does changing the percentage of sucrose added to yeast affect the rate of ...

    - http://easycalculation.com/statistics/standard-deviation.php Graph showing the effect changing the percentage of sucrose added to yeast has on the rate of respiration of yeast, as measured by the mean rate of gas bubbles (froth) produced by the yeast above the yeast-sucrose suspension in 360 seconds and the standard deviation in the form of error bars from the mean.

  1. Comparing the effect of different antimicrobials on the growth of E.coli

    All of the procedures were carried out as close to the bunsen burner as possible in order to avoid any contamination. A sterile cotton-stick was dipped into the broth culture of the organism (50% overnight culture of Escherichia coli and 50% sterile saline solution; prepared by the tutor)

  2. Investigating The Effect Of Temperature On The Respiration Of Yeast

    The enzyme’s optimum temperature is at 37°C, and starts denaturing at around 42°C; yeast contains enzymes which are required to carry out anaerobic respiration. When the temperatures reaches around 40°C, the active enzyme cell deforms and the hydrogen bonds break due to the increased kinetic energy, denaturing the yeast enzyme

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