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

To investigate the effect of changing the P.H. level during the fermentation of yeast; and to see how much the yeast ferments at the different P.H ’s.

Extracts from this document...

Introduction

James Mckenzie 10L Biology Course-work Planning Experimental Procedures Aim To investigate the effect of changing the P.H. level during the fermentation of yeast; and to see how much the yeast ferments at the different P.H 's. Prediction When the P.H. level is at a neutral point the amount of fermentation will be consistently higher, than if not. Therefore when the P.H. level is at a low or high number i.e. acid or alkali, the amount of fermentation will be considerably less than if it is at neutral P.H. The stronger the alkalinity or acidity will give even less fermentation than a weak acid or alkali. ...read more.

Middle

* Dissolve 8g of sugar in 125cm� of warm water (40 centigrade) * Add 15g of yeast and stir well * Leave for 7 minutes for the yeast to become active The experiment was set-up as shown on the separate sheet of paper. 1st experiment * P.H. 3 during fermentation. * 7 minutes left fermenting * 5ml CO2 gas 2nd experiment * P.H. 6 * 7 minutes fermenting * 15ml CO2 gas Decisions about Experiment The preliminary experiment showed the outline of the prediction we made. The first experiment whereby the P.H. was 3 showed that a low P.H. i.e. a strong acid does not produce a huge amount of acids. ...read more.

Conclusion

In the preliminary as soon as the method was set-up properly. This did not allow a long enough time for the fermentation to take proper affect. This was because the glass tube linking the boiling tube and the measuring cylinder was full of water. This water has to be pushed back down the glass tube, this slows down the fermentation, and does not allow a vast amount of gas to be collected. To stop this from happening we must start the stopwatch when the gas has actually reached the measuring cylinder. The time allowed for the gas to be collected is too short; it does not give sufficient amount of gas in order to see how the P.H. effects the fermentation. Therefore the time for each experiment is extended to 10 minutes to allow sufficient gas to be collected. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Aqueous Chemistry 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 GCSE Aqueous Chemistry essays

  1. Marked by a teacher

    The Effect of pH on the Strength of Keratin (hair protein).

    4 star(s)

    There will be five different splints to be used for the five different pH solutions in test dishes.

  2. Investigating the effects of varying pH levels on the germination of cress seeds

    To further support my hypothesis, I also noticed that although the remaining samples did germinate, the success of germination decreased as the level of acidity increased (with the exception of the samples given only distilled water), indicating that pH level does affect the germination of seeds.

  1. How much Iron (II) in 100 grams of Spinach Oleracea?

    Moles = 0.0002158 mol dm-3 The ratio of Potassium Manganate (VII) (aq) to Oxalic Acid is 1:1. Therefore the mol of Potassium Manganate (VII) (aq) used is equal to those used of Oxalic Acid (aq). Now that I know the mols present in the Oxalic Acid (aq)

  2. Investigating the effects of changing the concentration of different solutions on the refractive index ...

    Resistance is measured in ohms. At one time, the unit of conductance is measured in mho (the reverse of ohm, representing the reciprocal relationship between the two). The unit is renamed siemens after W. Siemens, who carried out extensive research into the behaviour of electricity.

  1. Calibrating pH meters

    to become trapped between the lenses and they eye and create extensive eye damage. The goggles can also protect the eye from objects being hurled across the laboratory by immature minds or by the smashing of glass which would send pieces flying in all directions.

  2. Establish what types of soil holds the most water and to see if changing ...

    reacts with any of the properties in the soil causing a chemical reaction to take place so that new products are formed and maybe even gases given off which will reduce the amount of water passing through the funnel. It would be another test to see if acid or alkaline

  1. Plan an Experiment to Investigate the Effect of pH on Immobilised Yeast Cells on ...

    To explain why enzymes speed up reactions it is based on the collision theory. The enzyme's, which are immobilised in the yeast-based beads, will give many active sites for the substrate (Hydrogen Peroxide) to bind ('lock') with. This will increase the collisions and therefore the rate of reaction.

  2. Preparation of Lactate from the fermentation of cabbage (Sauerkraut).

    = (12 x 3) + (1 x 6) + (16 x 3) = 36 + 6 + 48 = 90g/mol % Lactic acid = 5.62cm� x 0.1M x 90 g/mol 50 = 1.0116 = 1.01 %. Evaluation: The aim of this experiment was to produce lactic acid and find the acid content produced.

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