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

The effect of substrate concentration on the rate of decomposition of Hydrogen Peroxide when catalysed by the enzyme Catalase.

Extracts from this document...


Chemistry Coursework The effect of substrate concentration on the rate of decomposition of Hydrogen Peroxide when catalysed by the enzyme Catalase. Plan In this experiment I have to investigate experimentally, the effect that substrate concentration has on the overall rate of decomposition of hydrogen peroxide when catalysed by the enzyme Catalase. First I need to understand the hypothesis before starting the experiment. We have looked at the function of enzymes, the way they carry out reactions and also the effects of conditions on their reactions. Also the lock and key hypothesis, and the more recent induced fit model, enzyme- substrate complexes, and activation energies with and without enzymes, specificity and also the cause of denaturation of the enzyme. In organisms, such as ourselves, Hydrogen Peroxide is a by product of our metabolism. The oxidations of certain cells in our body produce this toxic chemical. The chemical itself is pretty stable, and can last for prolonged periods of time in our body, and because of it's toxicity, it must therefore be removed quickly. Catalase is the enzyme that will reduce the activation energy (energy needed to start a reaction), and increase the rate of the decomposition of Hydrogen Peroxide, so there is less chance of it intoxicating our cells. In this experiment, the source of our Catalase enzyme will be potatoes. It works very quickly to reduce levels of Hydrogen Peroxide when present. ...read more.


But adding too much substrate doesn't mean that the rate of reaction will continue to increase, this is because the enzymes will only have a limited amount of active sites, so when the maximum amount of reactions are taking place, the enzymes are said to be saturated as no further active sites are available until some of the reactions have taken place. Therefore the graph for this experiment should show gradual increase in rate as the substrate increases, but reach a maximum point and level out, when all the enzymes active sites are in use, as the graph shows below. From this information I know that my graph should definitely show an increase in rate of reaction as I increase the substrate concentration. I know that if I increase the substrate concentration by double, the rate of reaction will increase by double, so the rate is proportional to the substrate concentration, until the saturation point. 3) Enzyme Concentration The enzyme concentration is obviously as vital as the substrate concentration. This is because the enzyme provides the active site to which the substrate joins to form an enzyme-substrate complex. The enzyme most importantly catalyses a reaction, meaning it reduces the energy required to start a reaction, the first graph below shows this reduction of activation energy. So therefore increasing the enzyme concentration will provide more active sites for the substrate, Hydrogen Peroxide to form a complex with, allowing more products to be formed. ...read more.


Therefore if there are double the amount of substrate/enzyme molecules in a solution, double the amount of reactions will take place at once and the rate will therefore double as well. Safety Risk Assessment: Apparatus * Potatoes (Are the source of the enzyme Catalase) * Cork Borer ( To cut same sized potato rings) * Hydrogen Peroxide (Substrate forms enzyme-substrate complex with Catalase) * Ruler (To measure out equal sized potato pieces) * Scalpel (To cut the measured sized potato pieces) * Stopwatch (To measure the rate of reaction in each experiment) * Test Tubes and Rack (To hold the enzyme-substrate solutions) * Delivery Tube with Bung (To let Oxygen to pass through test tube into burette) * 50 cm3 Burette (To measure amount of Oxygen released at regular time intervals) * Water Bath (To use at different temperatures with enzyme-substrate solution) * pH Levels 2 to 7 (To use with enzyme-substrate solution under various pH's) * Thermometer 50�C (To measure room temperature and solution temperature) * Pipette Filler 10cm3 (To measure amount of Hydrogen Peroxide used) * Retort stand, Boss and Clamp (To support and hold the burette and test tube) APPARATUS USED ACCURACY Burette (50cm3 ) 0.05cm3 Thermometer 50�C 0.1�C Pipette Filler (10cm3) 0.06cm3 Stopwatch 0.5 seconds Methods: Temperature * Substrate Concentration * ?? ?? ?? ?? Khuram Pervez Page 1 of 10 ...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 Substrate Concentration On the Rate of Enzyme Activity.

    - ? R2 U1 = 6 x 6 + 1/2 6 (6 + 1) - 57 U1 = 36 + 21 - 57 U1 = 0 Critical Value = 5% confidence limits The lowest calculation U value is below the critical U.

  2. Investigation of the effect of adding different concentrations of NaCl to an enzyme-substrate (amylase-starch) ...

    The enzyme breaks down the starch molecules into dextrin, maltotriose, maltose, and glucose molecules. The methods of breaking down the starch are explained in the plan. In relation to the information about this topic in the sections above it would be appropriate to analyze the information to produce an educated hypothesis on how the substances involved will behave.

  1. To investigate the rate at which hydrogen peroxide is broken down by the enzyme ...

    accurate enough to prove my theory, that as the enzyme concentration increases so does the volume of O2 produced, because the rate of reaction has increased. This is because there are more active enzyme sites to react with the molecules of hydrogen peroxide, which means there are more collisions resulting in more successful reactions, which produces more oxygen.

  2. The effect of Copper Sulphate concentration on Catalase activity on Hydrogen Peroxide.

    This variable must be kept constant in order to abide by the fair test criteria. o Constant concentration of Substrate (hydrogen peroxide) - if more substrate is added, the enzyme cannot work any faster as it is all being used.

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

    Record the volume of gas collected every thirty seconds for 2 minutes so that you have four results for "0 cm3 of Celery Extract/5 cm3 Water" in the table below. This is the 'control' for the experiment. 20. Repeat this experiment 2 more times (steps 4 to 17), leaving out

  2. Investigating the effect of the Temperature on the Enzyme Catalase when it reacts with ...

    Produced froths, there was not enough oxygen present to light up the splint Yeast Reacted fast, produced bubbles and fizzed, the yeast went cloudy. Lighted up the splint very quickly and made a pop sound. The amount of catalase varies in different tissues.

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

    Enzyme act by binding substrates, forming a complex. The complex stresses chemical bonds forming a transition state. This makes the substrate more reactive. Energy is needed to form this state and the enzyme provides it. The enzyme's site of attachment and the parts that stress the substrate's bonds is known as the active site.


    adding Pi to ADP. Since oxygen is needed to act as a terminal electron acceptor, this process is also called oxidative phosphorylation. For each reduced NAD that enter the electron transport chain and is oxidised by NADH dehydrogenase, 3 molecules of ATP are made, while for each reduced FAD that enters the electron transport chain, 2 molecules of ATP are made.

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