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

An experiment to investigate the effect of substrate concentration on the rate of activity of the enzyme Catalase.

Extracts from this document...


An experiment to investigate the effect of substrate concentration on the rate of activity of the enzyme Catalase PLANNING Aim: This is an experiment to examine how the concentration of the substance Hydrogen peroxide (H2O2) affects the rate of reaction of the enzyme Catalase. The main purpose of this reaction is to find out how; by varying the concentration of substrate (H2O2) the rate of enzymatic activity of the enzyme catalase (which is present in liver) is affected. The rate of this enzyme-controlled reaction can be measured by the amount of oxygen (O2) given off compared to the amount of time it takes to fill the entire volume of the gas syringe. Scientific Knowledge We know that an enzyme is a protein which serves as catalyst - a chemical agent that changes the rate of reaction without itself being consumed by the reaction. Each different enzyme acts upon a chemical substance called a substrate, which fits into the active site of the enzyme like a lock would into a key (lock and key mechanism), during the reaction products are formed. A Catalase enzyme serves to protect the cell (e.g. liver or potato cells) from the toxic effects of hydrogen peroxide by catalyzing (breaking it down) into molecular oxygen and water - O2 and H2O. ...read more.


away from the active site - this action alters the shape of active site so that the substrate is unable to occupy it and the enzyme cannot function properly. The type of molecule which attaches itself away from the enzyme's active site - causing it to not function properly anymore is known as a non-competitive inhibitor. Inhibitors therefore slow the rate of reaction. As none are to be added to this investigation, there will be no effect from inhibition. e) Enzyme concentration - The amount of enzyme available to process the substrate can control an enzyme catalytic reaction. By carrying out this experiment we can investigate how doubling the amount of enzyme affects the enzyme catalysis rate, amount of substrate, and amounts of reaction products. Provided there is an excess in substrate, an increase in the enzyme concentration will lead to a corresponding increase in the rate of reaction. When the substrate is in short supply (i.e. it is in limited quantity) an increase in the enzyme concentration has no effect. Apparatus 1) 250ml conical flask and beakers. 2) 40ml Hydrogen peroxide (start off with 10vol and then the concentration will be varied thereafter) 3) Tongs 4) Distilled water 5) Liver (to be cut up into fine pieces which will weigh 1 gram each) ...read more.


If the concentration were doubled, I would expect the amount of Oxygen released to be a figure twice as much. From 10vol to 1vol shows a directionally proportional decrease in reactivity rate, after 10vol the rate of reaction slows down. At this point virtually all active sites are occupied making the active sites saturated with Hydrogen Peroxide. With an increase the concentration of Hydrogen Peroxide, the number of active sites increases, hence, makes a more violent reaction (Quicker). The theoretical maximum rate of reaction is when all the sites are being used but in reality this theoretical maximum is never reached due to the fact that not all active sites are being used at the same time. The substrate molecules need time to join onto the enzyme and to leave it so the maximum rate achieved is always slightly below the theoretical maximum. The time taken to fit into and leave the active site is the limiting factor in the rate of reaction. Safety Laboratory coats can be worn during the investigation to prevent chemicals from spoiling clothes. Care was also taken whilst handling the chemicals as hydrogen peroxide is corrosive and very toxic (harmful to the eyes and skin). Whilst using the razor blades, care was also taken to hold them by the handle and not the blade to prevent an accident occurring. Rameez Ali 126PAH ...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. Marked by a teacher

    The effects of Hydrogen Peroxide concentration on the activity of Potato Catalase

    4 star(s)

    Fill the measuring cylinder with water and invert into the beaker of water. Do not place the measuring cylinder over the end of the delivery tube. 6) Fill the syringe with 5cm3 of Hydrogen Peroxide and place into the bung hole.

  2. Marked by a teacher

    The Effect of Substrate Concentration on Enzyme Action.

    4 star(s)

    Results Table to Show the Results Obtained in the Preliminary Investigation Time (s)/ Volume of Oxygen (ml) Concentrations of Hydrogen Peroxide 100% 80% 60% 40% 20% 0% 0 0 0 0 0 0 0 10 2 2 2 1 1 0 20 5 5 4 2 2 0 30 10

  1. Marked by a teacher

    Enzymes - investigate how the substrate concentration (H2O2) affects the activity of catalase on ...

    3 star(s)

    I will use a water bath to maintain a constant temperature of 30?C in a beaker, throughout the experiment. This will ensure that all tests are carried out in the same conditions and the results are not obtained with the influence of an external factor.

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

    From the practical experiment that I have done, I think that I have got fairly reliable results. I think that my results are reliable because I have used several filter paper discs to repeat the same temperature over and over again, in other words I did six runs on the

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

    As temperature increases so does the rate of reaction. However one must also bear in mind that high temperatures can cause thermal Denaturation of the enzyme and freezing may also damage an enzyme. Denaturation is a change in the tertiary structure of an Enzyme. An enzyme's function is related to its 3-dimensional (Tertiary)

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

    test tubes and put them in the racks and label them 1 to 5. I will then add 5cm³ of milk to the ten test tubes using a graduated pipette. One pipette will be allocated to one substance so to ensure no contamination occurs, these pipettes will be individually labelled with its contents name, e.g.; milk for ease of use.

  1. An Investigation into the Effect of Varying pH on Enzyme Activity

    Apparatus Two 10 cm3 measuring cylinders- This cylinder is big enough to hold the buffer solution and the milk and the second measuring cylinder is to hold the protease. These will be washed out with distilled water before each repeat and experiment to minimise the chance of contamination Test tubes-

  2. An Investigation Into the Effect of Substrate Concentration On the Rate of Enzyme Activity.

    Although technically it is more difficult and it is hard to make all the enzyme beads the same size. However the start and end of the reaction are easy to determine so this method will be used. Apparatus and Chemicals Test tube rack, test tubes, syringes (10cm3), filter paper, filter,

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