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

An Investigation into the Catalytic Action of the Enzyme Peroxidase

Extracts from this document...

Introduction

An Investigation into the Catalytic Action of the Enzyme Peroxidase The enzyme peroxidase acts as a catalyst for decomposing hydrogen peroxide into water and oxygen. The equation for this is: 2H2O2 (aq) -->2H2O (l) + O2 (g) For this investigation fresh liver extract is used as this contains the enzyme peroxidase. The liver extract will be reacted with hydrogen peroxide and the peroxidase will act as a catalyst to speed up the reaction, producing water and oxygen. The oxygen will be collected as a measure of the rate of the reaction. To find the rate of reaction I will measure the amount of O2 cm3 and divide that by the time taken for each amount of oxygen to be produced. APPARATUS I think that the following apparatus is going to be the most suitable and reliable for the investigation: Conical flask with rubber bung tub of water Syringe Glass tubing Measuring cylinder SAFETY It is critical for safety levels to be maintained at a high standard throughout the investigation. It is important to be careful when dealing with hot water and liver extract. ...read more.

Middle

VARIABLES The factors that can affect the rate of reaction are: The temperature of the liver extract and hydrogen peroxide The concentrations of the reactants The concentrations of the reactants have to be the same throughout the investigation or else the test is not fair. The collision theory tells us that there is going to be a greater reaction (more oxygen produced) if there is a greater concentration of reactants. The quantity of the reactants Again using the collision theory I can tell that the greater the amount of reactants the larger the quantity of oxygen will be produced. Therefore it is important that the quantity of the reactants is kept the same throughout the tests to ensure a fair investigation. PREDICTION I think that the rate of catalytic reaction will increase in line with the increased temperature of the liver extract. This should occur because the higher the temperature of the liver extract the faster the peroxidase enzyme molecules move and the greater the chance of them colliding with the hydrogen peroxide molecules. Slower moving Faster moving Molecules molecules (less chance of collision)(Greater chance of collision) ...read more.

Conclusion

My prediction was proved by my results It is inevitable that not all of the oxygen in the final measuring cylinder will have been given off in the reaction because there will be a small amount of oxygen in the conical flask at the start of the investigation. The amount of liver extract used in the reaction will be slightly smaller than the original amount at the beginning of the investigation as some (1cm3)will remain in the end of the syringe. I have recognised both these factors, but as they occur consistently in each test I feel they did not effect my results. The small amount of oxygen collected when the liver extract was heated to 500C may have been due to oxygen already in the conical flask. If I had more time to perform the investigation I would have tested to find out more accurately at what temperature the peroxidase stopped working and died. It was not necessary to my knowledge to repeat any tests. This was because my concentration was maintained throughout the experiment. I also worked out how I could prevent oxygen getting into the measuring cylinder before the reaction took place. This made calculating the amount of oxygen gathered much simpler and gave less room for errors. ...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 Patterns of Behaviour 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 Patterns of Behaviour essays

  1. Factors Affecting the Rate of Catalytic Decomposition of Hydrogen Peroxide.

    There are several defects with the method. Firstly, it is quite difficult to obtain an initial rate as that would require multiple readings taken for various volumes given off which is reasonably accurate as it is based on human judgement - human error is very possible. Also, there was a limited range due to the size of

  2. The effect of aspirin on the action of bovine liver catalase

    x r2 x l, which is.... ? x 1 x 20 = 62.8 mm3 . To find a rate of reaction, which is in terms of the oxygen produced per second, divide the volume of oxygen produced (62.8 mm3) by the time taken.

  1. THE EFFECT OF BILE SALT ON THE ACTION OF THE ENZYME LIPASE

    Fatty acids are blocks of two types of lipids - storage fats and the structural phospholipids. Fatty acids possess a long hydrocarbon chain with a carbonyl group attached to its tail. These chains can be described as saturated or unsaturated.

  2. Enzyme Investigation.

    Hydrogen peroxide is formed in cells because it is a product when enzymes break down certain amino acids and fatty acids. Hydrogen peroxide is damaging to normal tissues and therefore needs to be broken down into harmless oxygen and water before it can escape.

  1. Factors Affecting Enzyme Activity

    have been pointless given that I am investigating the rate of reaction of several different liver concentrations rather than the rate of reaction changing over time in one concentration of liver. On the whole I am happy with my graphs and I think they verify my hypothesis.

  2. An investigation of a factor affecting the activity of Liver peroxidase enzyme

    It was left to equilibrate for 2 minutes. While this was being timed, the rest of the concentrations were made and put in the water bath. Also a 100ml measuring cylinder was filled with water and turned upside down in the water bath.

  1. Investigate the action of the Enzyme Catalyse

    Mass: The mass of potato will always be the same. It will be as accurate as possible and I will use the weighing scales to do this. Amount of H2O2: The amount of Hydrogen Peroxide will always be the same.

  2. Catalase activity in the liver

    in this experiment helps to speed up the rate of reaction and break down substances without itself undergoing any chemical change. An enzyme is composed of polymers of amino acids I have also found each enzyme is specific to one job so it can't be used in other reactions.

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