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

How does temperature effect the rate of enzymes?

Extracts from this document...

Introduction

Sana Javed T11EP Biology Coursework How does temperature effect the rate of enzymes? Aim I am going to investigate the effect of temperature on enzymes, using a potato as a catalyst. The potato contains the catalyst CATALASE. An enzyme is a protein molecule that speeds up chemical reactions in all living things. Without enzymes, these reactions would occur too slowly or not at all, and no life would be possible. They are reusable. Basically they are like biological catalysts. Enzymes are classified into several categories, such as hydrolytic, oxidising, and reducing, depending on the type of reaction they control. Hydrolytic enzymes speed up reactions in which a substance is broken down into simpler compounds through reaction with water molecules. Oxidising enzymes, known as oxidises, speed up oxidation reactions; reducing enzymes speed up reduction reactions, in which oxygen is removed. Catalase is present in the peroxisomes of nearly all-aerobic cells. Peroxisomes break down fatty acids and amino acids. These reactions produce hydrogen peroxide that could harm cells if it were allowed to persist. The enzyme (catalase) breaks down the hydrogen peroxide to water and oxygen, both of which can be used by the cell. It serves to protect the cell from the toxic effects of hydrogen peroxide by catalysing it into oxygen and water. The reaction we will be doing is: Catalase Hydrogen Peroxide ---> Water & oxygen Enzymes work by joining the substances together to make the reaction work faster. ...read more.

Middle

For a mammal this is around 35-37 c. as the temperature gets higher the rate of reaction will start to decrease because the enzyme is becoming denatured. The structure of the enzyme is changing and the active site will become destroyed as the temperature increases, then the substrate (hydrogen peroxide) will no longer be able to fit into the active site and the reaction will then stop (lock & key mechanism). This is shown in the graph below. The rate initially goes up as the temperature increases this is because the temperature changes the rate, as the temperature rises, the movement of enzyme molecules and substrate molecules increases. This causes more collisions between enzyme and substrate, and the result is the formation of more product, as the rate of reaction increases. Then the temperature rises beyond a certain point and the enzyme activity declines gradually because the heat, which destroys the active site so the lock and key mechanism cannot take place, as it denatures the enzyme. Also, if I apply twice as much heat there will be twice as much particle vibration therefore the reaction will happen twice as quickly. This is the kinetic theory. In the graph above we can see that the enzyme activity has increased quite quickly and as It reaches the optimum temperature which is 37 around this temperature the activity starts to fall as the enzyme has reached the temperature where it works best and now it is starting to become denatured as the temperature starts to cook the active site which is ...read more.

Conclusion

The anomalous results which I found could have been caused by many things such as the losing of gas during the experiment e.g. the bung might not have been tight enough which could of let some of the gas given off into the temperature rather than into the burette. Also as I said before the temperature wasn't as accurate as I could have been this could have caused there to be anomalous results. If I look at my graph I can see two main anomalous results, which are at 50 and 60, they were firstly too close together showing that the gas given off was mostly the same amount, this may be due to that temperature was not correct or gas was given off into the atmosphere. Though my results are in line with those that I predicted. The graph indicates the rise in temperature up to a point leads to an increase in oxygen production. This is in lint with the kinetic theory. However it is very clear that after a certain temperature is reached the enzyme actually stops and starts to decrease this supports my theory of lock & key fit. Overall, due to reliable repeats and in general predictions being confirmed I feel my results are reliable. Further experiments that I could do, would be to change the catalase used. Also, I would have done the experiment with a piece of liver too, just to make sure that the catalyse activity is the same in the liver as the potato. Although, I already know from what I have been taught, that the liver would give similar results to the potato. Sana Javed T11EP 02/05/2007 ...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 Life Processes & 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 GCSE Life Processes & Cells essays

  1. Marked by a teacher

    Plan: The effect of the end product, phosphate, on the enzyme phosphatase

    5 star(s)

    * Time for enzyme activation In this experiment, if given sufficient time the enzyme will break down all the substrate in all tubes since phosphate is probably a competitive inhibitor, and it will result in no color difference between any test tubes.

  2. Marked by a teacher

    Biology Coursework Enzymes

    4 star(s)

    * Fourthly I will measure 2 ml of 1% starch into my cleansed 10ml-measuring cylinder and then pour the starch into another one of my boiling tubes. * I will then measure 8 ml of water using my washed

  1. The effect of temperature upon the enzyme catalase

    Also the error bars for the set of results at 23oC and 40oC overlapped, the highest result for 23.4 was higher than the lowest result at 40. I also worked out the standard deviations for each set of data at each of the temperatures.

  2. Investagating the Action of the Enzyme Catalase On the Surface Area of a Potato.

    produced as the surface area increased was less than what I should have gained allowing the results not to fit in with the line of best fit. These results do not seem as reliable as the other two sets. However, even in set 2, there are two results, which do

  1. What influence does pH have on the enzyme Catalase?

    However, the method did not manage to control all the possible variables. Temperature also has a significant effect on the rate of enzyme reactions, so it should have been controlled as having different temperatures would have given very different readings.

  2. The Effect of Temperature on Enzyme Activity.

    Having the same shape and size means that the cores will all have the same surface area. The surface area of the potato cores affects the rate of oxygen production as the larger the surface area, the more catalase molecules make contact with the hydrogen peroxide molecules and thus the more oxygen produced.

  1. The effect of hydrogen peroxide on catalase if you change the temperature.

    � Also to average out the results. Safety precautions � Wear goggles � Tuck tie in skirt � Wear work shirt � Handle the hydrogen peroxide with care as it is corrosive and an irritant Predictions and Reasons From my research I think that the enzymes will denature after 40�C and any other temperature above that.

  2. For my coursework I had to study enzymes (catalysts) and the rate of reaction ...

    outliers as we cannot guarantee the performance of the equipment and the variables surrounding it. I also predict that the Preliminary test will go in my favour and support my hypothesis. This will then be further supported hopefully, by the reliability of my graph.

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