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

Enzyme Coursework. Investigation to find the effect of substrate concentration on the rate of an enzyme controlled reaction

Extracts from this document...

Introduction

Investigation to find the effect of substrate concentration on the rate of an enzyme controlled reaction Design Aspect 1: Defining the problem and selecting variables Investigation title: is the rate of an enzyme controlled reaction affected by substrate concentration? Background information Enzymes are often referred to as "biological catalysts", since they increase the rate of reactions in living organisms. Enzymes are also substrate specific, which means that only a specific substrate can fit into its active site (which is where the catalysing effect occurs) and as such, there are different enzymes which deal with different reactions (for example, protease breaks down proteins into amino acids) - this is the basis for the 'lock and key' theory. The stages of an enzyme controlled reaction are: 1) Enzyme + substrate The enzyme and substrate are in solution together 2) Enzyme substrate complex A substrate has moved into the active site 3) Enzyme product complex The reaction has taken place, but the products haven't been released from the active site 4) Enzyme + product The enzyme and product are now in solution together (after the product was released from the active site) ...read more.

Middle

* the volume of the solutions 10cm� of hydrogen peroxide will be measured out by using a measuring cylinder for each test. * the temperature of the solutions The experiment will take place in an air conditioned laboratory, so it can be expected that the temperature will not vary enough over the course of the experiment to have a significant effect. * the pH of the solutions 1ml of pH7 buffer will be added to the solution. Aspect 3: Developing a method for the collection of sufficient data Apparatus * Hydrogen peroxide 1.00mol/dm-3 (150cm�) * Distilled water (75cm�) * Syringe (10cm�) * 15 test tubes * Stopwatch (seconds) * Pieces of paper * Hole punch * 3 petri dishes * 5cm� catalase enzyme * Safety glasses * pH7 buffer * Tweezers Method Preparing the hydrogen peroxide solutions Using the table below, prepare the various concentrations of hydrogen peroxide: Volume of distilled water (cm� ) Volume of 1mol/dm-3 hydrogen peroxide (cm� ) Concentration of hydrogen peroxide solution (mol/dm-3) 8.00 2.00 0.20 6.00 4.00 0.40 4.00 6.00 0.60 2.00 8.00 0.80 0.00 10.00 1.00 Label 5 rows of 3 test tubes with the different concentrations (0.20mol/dm-3 to 1.00mol/dm-3) ...read more.

Conclusion

As a result of this, the concentration of the enzyme present on the pieces of paper is uncertain (being soaked for a longer time will allow the piece of paper to absorb more catalase, which would speed up the reaction as there would be more of the enzymes). This does make the investigation less reliable, but the effect would have probably been only slight; however, to improve on this, the length of time that each piece of paper is soaked should be timed and kept the same. * Timing - although only a minor issues, human reflexes add a small margin of error in the times of each result, since the timing had to start as the pieces of paper touched the substrate and as soon as they touch the surface again. A computerised system could used in place of a human, but this would be costly and impractical to setup. * The concentrations of hydrogen peroxide didn't show the plateauing effect that was predicted - to improve on this, a greater range of concentrations could be used (for example 0.5M to 2M) which would clearly demonstrate the effect and completely prove the hypothesis. Steven Burnett IB Yr1 IB Biology Coursework 03/01/2011 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Here's what a star student thought of this essay

5 star(s)

Response to the question

This Biology IA is outstanding in content and presentation, combining very accurate background information, easy-to-follow procedures listed out, relevant data presented in a coherent manner and insightful discussion and evaluation as well. The background information is more than needed and ...

Read full review

Response to the question

This Biology IA is outstanding in content and presentation, combining very accurate background information, easy-to-follow procedures listed out, relevant data presented in a coherent manner and insightful discussion and evaluation as well. The background information is more than needed and highlights just what is relevant instead of beating around the minor, irrelevant details. The IA mentions the investigating title but needs to reassert this by including the “aims and objectives” of the IA. The hypothesis needs more improvement as it is rather inaccurate and blur in focus, simply mentioning that there is an “effect” but without describing this effect or justifying why the effect will be as such. The writer identifies the correct independent and dependent variables while lists out a range of control variables as well. The writer also elaborates on these variables, how the concentration of peroxide solutions are varied, how the time taken is measured, how the various control variables might affect the experiment if they were different and so how they are maintained at a constant level as well. Coupled with very simple procedures, the IA also presents data very neatly and coherently. In the conclusion, the writer follows up on the data collected to conclude, justifying each conclusion with data. The evaluation section provides realistic ways to modify the experiment to improve it, and these modifications can actually enhance the experiment by a large margin, so the IA definitely answers the question overall.

Level of analysis

The IA definitely exceeds expectations in several aspects of analysis but also needs more improvement in other aspects. For example, the hypothesis needs more improvement as it is rather inaccurate and blur in focus, simply mentioning that there is an “effect” but without describing this effect or justifying why the effect will be as such. However, the variables section is very well done and can score well among markers as the writer elaborates on each variable instead of just listing them. The materials and apparatus section actually not just lists equipment used but also mentions other details such as quality, quantity, concentration and other details where relevant. Instead of listing the steps, the writer actually splits the IA into different sections and then lists the procedures under these sections. This enhances the organization of the IA. All tables show data with correct number of decimal values, the correct units, proper headings so the IA scores on data presentation as well, but to improve the uncertainties of instruments can be indicated as well to justify the decimal values of data. The evaluation section is excellent in that it lists of shortcoming of a specific procedure, explains how this might affect data, recommends other ways to improve and justifies how this might not affect data negatively. But, the quantity of evaluation could be increased as well.

Quality of writing

The whole IA has an excellent presentation. There are very few grammar or spelling errors but even these are not glaring errors. The use of technical terms is adequate and the IA explains the biology behind the whole IA. The IA defines technical terms where needed as well.


Did you find this review helpful? Join our team of reviewers and help other students learn

Reviewed by Arcturus 13/03/2012

Read less
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 International Baccalaureate Biology essays

  1. Marked by a teacher

    Neurology and Behaviour. Focus question: Is there an increase in the perception and ...

    5 star(s)

    These parasitic agents can enter a host's body via the nose, skin or sexual organs, not simply via the mouth. Disgust has since basic times evolved with the formation of society and due to this in the social domain individuals may experience disgust by the presence of immoral or unjust actions.

  2. Marked by a teacher

    Osmosis Internal Assessment (Biology)

    4 star(s)

    to the region of lower water concentration (potato strip). When a longer period of time was given for osmosis to occur, a plateau in the mass of the potato strips could be seen whereby most of the potato strips stopped increasing in mass at 3.6 grams, indicating that after 4 hours of immersion in the distilled water, the potato

  1. Marked by a teacher

    The effect of Pectinase Concentraton on the production of apple juice

    plot the graph was proven appropriate as the results were satisfactory, because it clearly shows the overall trend that was occurring supporting the hypothesis of an increase in apple juice in relation to Pectinase concentration. The best fit curve used to make the emphasize and highlight the trend that was

  2. Biology Lab Report-Osmosis

    A solution which brings about such changes is known as hyper-osmotic solution. Each cell becomes flaccid and the chip as a whole shows the net result of these changes. In some cases, the concentration of solution outside a cell is the same as the concentration of solution inside the cell.

  1. Biology HL IA - Transpiration lab report

    As can be seen from the Chart 2, the values of transpiration rate (mL/m2min1) decrease from first step to second (from 0.043 to 0.041) but there is a steep increase in the third step (from 0.041 to 0.068). This could be explained that, although transpiration rate depends straightly on the area of leaves, e.g.

  2. Biology Lab Report - Effects of Mouthwash on Oral Bacteria

    How effective is water at killing mouth bacteria? Support your answers with your data.

  1. Browning Enzyme

    occurs at warm temperatures when the pH is between 5.0 and 7.0. 3The reduction in browning is dependent on the type of substance and its concentration, soaking in water is all that is needed however, sucrose solution in this case was more desirable.

  2. The Effect of Temperature on the Vitamin C Content of Lemon Juice

    This meant that we recorded results that weren?t actually completely colourless, effecting both the reliability and validity of my results. Next time a colourimeter could be used. Distilled water would first be measured to calibrate then that result would be used as the measure of ?colourless?, so the solution would

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