• 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 Action of Bile Salts on Fat in Milk

Extracts from this document...

Introduction

Experiment to Investigate the Action of Bile Salts on Fat in Milk Planning Variables Temperature - room temperature Full cream milk concentration - 2.5 cm3 per test tube Bile salts concentration - We will investigate this variable at different values Lipase concentration - 0.5 cm3 per test tube Sodium carbonate - 3.5 cm3 per test tube Distilled water - This will vary according to the amount of bile salts in each tube Phenolphthalein - 3 drops We can easily change the concentrations of bile salts by changing the amount of bile salts in each test tube. We can easily keep the temperature constant by doing all the experiments at the same time in the same part of the laboratory. Because we are going to work at room temperature this will keep the temperatures roughly similar. We have chosen room temperature because it is the easiest temperature to keep constant. We are using test tubes to carry out the experiment in so the values of the milk, lipase and sodium carbonate work best at this scale. We will use 3 drops of phenolphthalein as it is only an indicator and so does not need to be measured very accurately and 3 drops will show the colour change clearly enough. ...read more.

Middle

Phenolphthalein is pink/purple in acid and clear in alkali. We will use the syringes to add the rest of the necessary liquids. The lipase is the enzyme that will break down the fat in the milk. We will use full cream milk as it has more fat content. The milk will all be taken from the same carton to ensure that the experiment is a fair test. The bile salts are emulsifiers; they will break down the fats and so increase the surface area of the fat droplets. We will use distilled water to keep concentrations in all tubes equal. Distilled water is purer than tap water and so better for this experiment. The sodium carbonate is added to make the solution alkaline to begin with so the colour change is obvious. We will use the stopwatch to find the amount of time it takes for the solutions in the test tubes to turn cloudy white. Test Tube 1 Test Tube 2 Test Tube 3 Test Tube 4 Test Tube 5 Lipase 0.5 cm3 0.5 cm3 0.5 cm3 0.5 cm3 0.5 cm3 Milk 2.5 cm3 2.5 cm3 2.5 cm3 2.5 cm3 2.5 cm3 Sodium Carbonate 3.5 cm3 3.5 cm3 3.5 cm3 3.5 cm3 3.5 cm3 Bile Salts 0 cm3 0.1 cm3 0.25 cm3 0.4 cm3 0.5 cm3 Water 0.5 cm3 0.4 cm3 0.25 cm3 0.1 cm3 0 cm3 Phenolphthalein ...read more.

Conclusion

All we would need to do would be to keep the amount of bile salts and distilled water fixed. I would keep the amount of bile salts fixed at 0.5 cm3 so that the reaction does not take too long. We would not need to add any distilled water as there is water contained in the milk. We could use 5 test tubes and test at 20�C, 30�C, 37�C, 45�C and 55�C. We would use water baths to regulate the temperature in each test tube. However the disadvantages are that a water bath is not very accurate and takes a long time to warm up. Also it is hard to make sure that the contents of the test tubes are the same temperature as the water outside the test tubes. I would expect the test tube at 37�C to react the fastest as this is body temperature and therefore the temperature that lipase normally works at in the small intestine. At lower temperatures the enzymes have less energy and so works slower and at higher temperatures some of the enzymes become denatured and so do not work therefore the reaction is slower. If I drew a graph of temperature versus rate of reaction with temperature on the horizontal axis and rate of reaction on the vertical axis I would expect the graph to rise steeply from 20�C to 37�C and then to decline rapidly from 37�C to 55�C. ?? ?? ?? ?? Ahmed Luqman page 1 ...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. In this experiment, we aim to investigate the effect of sodium carbonate on hard ...

    would continue at the 1.50 cm3 of soap solution mark regardless of how much powder was used for the test. This is because the sodium carbonate loses its effectiveness due to the fact that all the calcium ions will have already been removed by it, and so it is just

  2. Preparation of Salts.

    The alkali is very caustic. This means it will wear away into wood or anything in its way. The only way to stop this from happening, is to neutralise it by pouring an acid over it. We then titrate the hydrochloric acid solution with the solution from the burette until we reach the 'equivalence point,' (end point).

  1. The action of amylase and pectinase in varying amounts when clarifying cloudy apple juice.

    I will also mark the 11cm� level up to which I have poured the distilled water. The amylase arrives as a powder and so I am going to mix it with water to make a 1% amylase solution. I will do one pilot experiment with everything at room temperature and

  2. What effect do different concentrations of bile have on the lipase activity?

    Using the grease pencil, label the test tubes 1 through 5. 2) Place test tubes in the test tube rack, 3) Take the test tube labelled 1 and measure 8mL of cream, 10mL NaCO3, and 2mL lipase into the test tube.

  1. Production of Epsom salts

    Inform staff and seek medical attention. Help the person if possible. Sulphuric acid Corrosive - it could burn the skin. Can be dangerous if it gets in your eyes. Low risk if low concentration is used. Wear safety glasses at all times that the practical is going on.

  2. Investigate and compare the amount of proteins, lipids and carbohydrates in three different types ...

    Place the test tube containing 1.3 cm3 of milk and the Benedict's solution in the beaker with hot water. 5. Observe and record any change in colour of the milk. If reducing sugars are present the milk should turn brown-orange.

  1. The action of lipase.

    With a graduate pipette 1 cm3 unboiled lipase solution is placed in test tube 2. 6. With a graduate pipette 2 cm3 unboiled lipase solution is placed in test tube 3. 7. With a graduate pipette 4 cm3 unboiled lipase solution is placed in test tube 4.

  2. Precipitation of Salts & Identification of Unknown Solutions

    In order to balance concentration levels of the solutions, a measurement of each required solution can be given so that more accurate results will be produced. Using thoroughly clean and dry test tubes will eliminate the possibility of cross contamination.

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