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

Investigation: Enzymes

Extracts from this document...

Introduction

Investigation: Enzymes BACKGROUND INFORMATION Aim To discover how temperature will effect the reaction rate between the enzyme Catalase and Hydrogen Peroxide. PROPERTIES OF ENZYMES * They are specific in their work; one enzyme speeding up one reaction only. * They are all proteins * Heat alters enzymes so they work at different rates. At certain high temperatures enzymes denature * They can be reused * They all require water before being able to function * Living cells are the only producers of enzymes. * They work within a narrow range of temperature. ENZYME CONTROLLED REACTIONS Enzymes are usually given a similar name to that of the substrate but ending in 'ase'. The reaction has two arrows because the reaction is reversible. If there is more maltose than glucose, the reaction will go from left to right and the other way round. How do enzymes work? Molecules are constantly active. When a substrate molecule bumps into a molecule of the correct enzyme, it fits into a depression (the active site) on the surface of the enzyme molecule like a key into a lock. The reaction occurs and then the molecules leave the site freeing it to react again with another substrate. If an enzyme is altered by heat, the shape of the active site is changed so that the substrate no longer fits. ...read more.

Middle

RESULTS These results below are the ones collected from the final experiment: Temp �C Time taken to collect 10cm� (s) Average Time (s) 10 236 255 251 247.3 20 165 181 154 167.3 30 90 97 86 91 40 52 60 57 56.3 50 122 143 286 183.6 60 / / / / 70 / / / / The result in read is anomalous and will be explained in my evaluation. This table shows the reaction rates of the experiment: Temp (�C) Volume of O2 given off Time taken Reaction Rate (1/t) 10 10 cm3 ? 247.3 seconds = 0.040 Secs-1 20 10 cm3 ? 167.3 seconds = 0.059 Secs-1 30 10 cm3 ? 91 seconds = 0.109 Secs-1 40 10 cm3 ? 56.3 seconds = 0.177 Secs-1 50 10 cm3 ? 183.6 seconds = 0.054 Secs-1 From this table above, the highest rate of activity is at the temperature of 40�C and these results show very clearly what I predicted earlier in my hypothesis. My hypothesis stated that the best temperature to keep the enzyme Catalase working at is 40�C and anything higher than this optimum temperature will decrease because the enzyme has denatured. My two graphs portray this theory clearly. The first one is showing the increase in the release of gas is affected by the increase in temperature and the second graph is showing the energy levels of the enzyme throughout the ...read more.

Conclusion

Investigation variations This experiment went very well overall, although the factors I have discussed above did not seem to accredit the method very well. The major weakness with the method we used was only the loss of gas during the process of connecting the bung to the conical flask this meant anomalous results could be recorded. The best way to solve this problem is not to adapt the current method, but to change it completely. I think that an alternative method of conducting this experiment would be to measure something other than the gas release. In laboratory, controlled conditions it is much easier to measure gas release but in a classroom, that certain method is unreliable. One idea is to measure the weight difference. This alternative method could be as follows: 1. Place a conical flask containing a fixed amount of Potato in onto the scales. 2. Take the weight of the flask and contents & add it to the weight of the fixed amount of H2O2. 3. Keeping the conical flask on the scales add the H2O2 to the flask. Every 10 seconds you can take the reading of the weight as it decreases on the scales. From this I can work out the weight difference.This difference will represent the content given off as gas and from this I can get a reaction rate, which is the goal I am aiming for. Biology Coursework 2002 Louise MacDonald 11MH ...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. Catalyse Investigation

    the room (the borer expands with a rise in temperature, affecting the size of the cylinders), although only a minor consideration, the way in which I trim the cylinders to have the same weight and the density of the potatoes (which could change due to incipient plasmolysis).

  2. Amylase Investigation

    Personal Care: biotechnology ingredients for personal care products. Protein: improvement of nutritional and functional properties of animal and vegetable proteins. Development of flavour bases based on proteins. Pulp & Paper: control of pitch problems. Reduction of chlorine consumption in pulp, bleaching, viscosity control in starch-based coatings, de-inking for recycling programs.

  1. Investigate how concentration of the enzyme catalase in celery tissue alters the rate of ...

    In addition to this, from the results it has also been confirmed, when an enzyme is present the rate of reaction increases. From both graphs, we observe that in each line there is a steep gradient within the first minute, followed by a more level line.

  2. Biology Coursework on Enzymes.

    This was the reason why the experiment never took place. The next problem that I encountered was that, the very first results that I obtained came out very weird, I found out that the when the reaction took place the contents in the tube went from cloudy in colour to colourless and then cloudy again.

  1. Hydrogen peroxide (H2O2) an Enzymes Investigation

    I will go further in to the rates of reaction later on in the planning. But the speed of the molecules being increased gives a better chance for the bond to be broken so it can react, but if there is a permanent change in the bonds being broken it is called denaturing.

  2. Enzymes Investigation

    Enzymes are made to be specific, this means that they can have only one substrate that they will work on. Each enzyme has an active site that is where their own specific substrate's molecule will fit into. Enzymes all work best at an optimum temperature that is usually body temperature at 37C.

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