• 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 temperature on enzyme activity

Extracts from this document...


5/2/02 Experiment to investigate the effect of temperature on enzyme activity Aim The effect of temperature on enzyme activity can be tested in different ways using different enzymes. In this experiment we will be testing the effect of temperature on the activity of Rennilase in the clotting of milk. We will test the time it takes for the milk to clot with this enzyme at different temperatures. Background Information * Enzymes are biological catalysts. * The way enzymes work can be described as the lock and key theory * Enzymes are affected by concentration * Enzymes are affected by PH * Enzymes are affected by temperature 1) Enzymes are Biological Catalysts * Enzymes speed up chemical reactions without changing them (making them a catalyst as this is what a catalyst does). * Reactions that build up larger molecules are called Anabolic reactions. * Reactions that break larger molecules to smaller molecules are called catabolic reactions. 2) The way enzymes work can be described as the lock and key theory * An enzyme provides a place for a reaction to take place. This is called the active site. * The molecule that is going to react is called a substrate molecule. It fits exactly into the active site (hence the lock and key theory the active site is the lock and the substrate molecule the key). * The enzyme then tweaks the substrate molecule so that they form a product. ...read more.


Diagram Safety Safety glasses were worn throughout the experiment to protect our eyes from the rennilase and other substances. Lab coats were worn also to protect us from rennilase as it can digest protein and therefore could be irritable to our skin. If our skin came into contact with rennilase it was washed off immediately. Method 1) Water baths for the temperatures 30,40 and 50�C were prepared. 2) For 0�C ice was placed in one of the large beakers. 3) For 60 and 70�C water of those temperatures were placed in the two other beakers. 4) All of these baths had their temperatures checked and maintained through out the experiment. 5) 6 test tubes were placed in a test tube rack. 6) 1cm� of rennilase was added to 3 of them. 7) 9cm� of milk was added to the other 3. 8) All six test tubes were placed in the beaker containing ice and the temperatures of the milk and rennilase monitored. 9) When the temperatures of the contents in the 6 test tubes reached the temperature of the water in the water bath, the contents of the 3 test tubes containing milk were added to the 3 test tubes containing rennilase and a timer was started. 10) The contents of the test tubes were observed and when the milk clotted the timer was stopped and the time it took for the milk to clot was recorded. ...read more.


This means that the accuracy of the times recorded may have varied. If I was doing the experiment again I would make sure that only one person was assessing this. Limitations If I could repeat the experiment I would give myself a lot more time. I would do this because it was difficult to monitor the results from several sections of the experiment running at the same time. If there had been more time the problem of subjective judgement would have been reduced because one person could obtain all the results. There were insufficient stop watches to monitor each sample. There were insufficient water baths as there were not ones for 0�C, 60�C and 70�C. Further research If I had unlimited time I would investigate the following because I believe they may have an effect on the reaction time: * Types of milk. * PH -Buffer solutions to make different acidities of the medium. Rennilase works in the stomach, which has a PH of about 2. Where as in this experiment the medium in which the rennilase was working had a PH of 7. I would investigate the effect of PH on rennilase. Anomaly In this experiment we had to repeat one of the results for 50�C because the rennilase denatured before we mixed it with milk and so no clotting took place. This confirms that while the reaction rate was maximum at 50�C it is not the optimum temperature. ...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. Investigating the effect of pH on the activity of an enzyme.

    The results will be plotted on a graph and the points will be joined this is so that the data will be easier to analyse and to see trends between the absorbency and pH. By looking at the result of averages on the graph it shows that it is a

  2. Investigating the Effect of pH on Enzymes

    there for a further eight minutes in the boiling water so the Benedict's test for reducing sugars could take place. The Benedict's test- This is a test for the presence of a reducing sugar or sugars. The Benedict's reagent is made up from an alkaline solution of copper sulphate CuSO4 that is blue in colour.

  1. Trypsin. Hypothesis: - I hypothesize that as the temperature increases the rate of enzyme ...

    Test tubes: - To keep the potato piece and hydrogen peroxide for the reaction to take place. 7. Rubber tubing: - To stop the oxygen release during the reaction to go out into the atmosphere. 8. Knife: - To cut the potato into pieces.

  2. for this experiment my main aim is to investigate the effect of temperature on ...

    Enzyme has various factors affecting its activity. But the one to be considered in this experiment is Temperature: Temperature can directly affect the rate of an enzymatic reaction. Firstly, all chemical reactions are affected by temperature, according to the laws of thermodynamics; in general chemical reactions speed up as the temperature is raised.

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

    result in a faster rate of reaction up until the point where lipase becomes rate limiting and milk lipid molecules are hugely in excess of the lipase enzyme. In this case, there would simply be too few enzymes to catalyse much of the substrate (milk lipid)

  2. To investigate the effect of pH and temperature on the rate of hydrolysis of ...

    Seek medical attention if irritation develops or persists. * As glassware will be used, the up most care to prevent breakage will be taken. This includes never placing cylindrical glassware on the bench where it is able to roll off.

  1. The effect of concentration of vegeren on clotting times with three different milks, whole ...

    I think that the higher the concentration in vegeren added to the milk, the more the milk will coagulate in the set time and the longer it will take to drain the milk mixture from the syringe. Also the milk with the higher content of fat will coagulate more in

  2. I am going to investigate the effect of pH and temperature on the activity ...

    * Repeat steps 4 & 5 (for the amylase & starch solution mixture) every 30 seconds until a blue/black colour no longer develops. * When there is no further change in the colour of the iodine, take the starch-amylase test tube, add Benedict's reagent, and place in the water bath for 1 minute.

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