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

Investigation into the effect of temperature on the digestion of fat by Lipase.

Extracts from this document...


Investigation into the effect of temperature on the digestion of fat by Lipase: by Chris Lisle Lipase is an enzyme- enzymes are biological catalysts made up from protein. Catalysts speed up the rate of reaction in an experiment without using itself up. Enzymes can be denatured at conditions of high pH or temperature this occurs because increased temperature causes the molecules of the enzymes to vibrate so violently that they break their weak bonds. Enzymes also have an optimum temperature of 37 which is about body temperature, which explains why they work very well within the human body. The process of the digestion of fat by lipase will be maintained by using the pink phenolphalein, coloured pink- which will turn colourless when in acidic conditions. In order to show the phenolphalein at a pink colour it must be regulated at an alkaline pH in order to do this we must add Sodium carbonate to give an alkaline pH. ...read more.


The phenolphthalein turns colourless due to the production of acid throughout this experiment. Fat -----------> fatty acids + Glycerol. The aim of this experiment is to discover the effect of temperature on the digestion of fat by lipase. The Independent variable in this investigation is temperature the other factors will remain the same to see what effect the temperature will have on the dependent variable digestion. I will test the digestion of fat in the following temperatures: 20 ,30 , 40 , 50 , 60 ,this is because the range covers the optimum temperature of an enzyme's rate of reaction and also allows it to experience high temperatures. Method: 1. Place in a test tube. 3cm milk 1cm lipase 3drops phenolphalein 2cm Sodium carbonate 2. Place the test tube in a water bath at room 20 . 3. Using a stopwatch time how long it takes for the colour to change from pink to colourless. ...read more.


The results above do not show the relationship between digestion of fat by lipase and temperature to that I would have hoped. The table of results show that the fastest reaction in this experiment was 60 These results do not confirm my prediction that enzymes would work best at around body temperature. However as the enzymes haven't been denatured it shows that the enzymes must have been more heat stable- this can depend on a number of things- for example how old the enzymes are. Evaluation. I believe that I worked well throughout this experiment and although my results did not follow my prediction that they are a "one off" dependent on the nature of the enzyme. I think this experiment could have been improved by using a computer to time the experiment and use a computerised thermometer to check the temperature of the water baths to more accuracy. You could test this experiment for another type of food e.g. sugar using benedict's solution at different temperatures to see if the enzyme followed the same pattern or followed my prediction. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Molecules & Cells 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 AS and A Level Molecules & Cells essays

  1. An investigation into the effect of lipase concentration on the rate of lipid digestion ...

    36 cm3 The bile salts will be added in one set of 6 tests to investigate their effect in addition to lipase.

  2. A2 coursework- The effects of bile salts on digestion of fat

    7.69 9.33 24 10.04 7.68 9.33 26 10.04 7.62 9.33 28 10.02 7.55 9.33 30 10.00 7.43 9.33 Percentage change in 30 minutes Food stuff milk Cream Egg % change (2 decimal places) 3.29 24.65 5.47 Conclusion I have found out from my preliminary work that cream has the biggest

  1. Comparing the effect of different temperatures on free lipase and immobilised lipase

    When the digestion of fats produces enough acid to bring the pH below 8.3 the phenolphthalein changes from pink to white. This is obvious result but it is not always easy to tell when all the pink colour has disappeared Key Variables The lipase and sodium carbonate concentration must be the same for all the experiments.

  2. An experiment to investigate the effect of enzyme concentration on the rate of milk ...

    is simply not enough lipid for it to emulsify all at once. ==> How bile concentration will be kept constant. Most obviously the same type of measuring instruments will be used each time and the same measures (2cm3 ) will be taken, using the same graduated pipette.

  1. Amylase Investigation

    A theory to explain the catalytic action of enzymes was proposed by the Swedish chemist Savante Arrhenius in 1888. He proposed that the substrate and enzyme formed some intermediate substance, which is known as the enzyme substrate complex. The reaction can be represented as: S + E ES Or it

  2. Catalyse Investigation

    Its decomposition therefore needs to be speeded up greatly in order to prevent it from intoxicating the cell. This is where catalase comes in. Catalase has to be very fast acting to keep the hydrogen peroxide levels low, and it is one of the fastest acting enzymes known.

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