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

The Effect Of pH On Invertase Activity.

Extracts from this document...

Introduction

The Effect Of pH On Invertase Activity Introduction Invertase Sucrose+water glucose + fructose Invertase is an enzyme which is usually found in plants. It acts as a catalyst for the hydrolysis of sucrose. (Campbell&Reece,2002) Sucrose is a disaccharide composed of glucose and fructose linked by a glycosidic bond. When this bond is cleaved in a hydrolysis reaction, an equal amount of glucose and fructose. Invertase is a significant enzyme because glucose is an important product of photosynthesis. Invertase is also used in the confectionery industry where fructose is preferred over sucrose because it is sweeter and does not crystallize easily. The reaction is shown as follow: Enzymes are affected by changes in pH. (Campbell & Reece, 2002) Extreme pH values generally result in loss of activity for most enzymes. Furthermore, there is a most favorable pH for enzyme - the point where the enzyme is most active. ...read more.

Middle

The 5 test tubes were gently shaken. Then, they were put into a water bath at 37 degrees Celsius for 5 minutes. One drop of 1 drop/ mole Benedict solution was added to each of these 5 test tubes after the 5 minutes incubation. The 5 test tubes were then shaken gently. Finally, the test tubes were put into a water bath at 85 degrees Celsius for another 5 minutes. Observe and record the colour change for each of the 5 buffer solutions containing invertase, sucrose and Benedict solution. Result Invertase's activity differs when placed in solutions of different pH level. Invertase is active at pH 4. It lost its activity at pH of 2, 7, 9, 11. This is shown as the solution with pH of 4 changed its colour from blue to red.(Table 1) In contrast, the solutions with pH of 2, 7 , 9, 11 did not change its colour and stayed blue.(Table 1) ...read more.

Conclusion

This suggests that different enzyme have different optimal pH values. This is significant, because the optimal pH of an enzyme specifies where the enzyme will be active in organisms. For example, pepsin is a specific enzyme found in the gastric juice in stomach. Gastric juice has a pH of about 2 and pepsin functions the best under pH of 2 to hydrolyze protein. By this experiment, the optimal pH can only be approximated to 4.We cannot measure the exact range of pH where invertase is active. Therefore, in this experiment, we do not know the optimum is broad or narrow. Also, we cannot know whether a small pH change would have a large effect or small effect. However, we could repeat the experiment and investigate the effect of pH on invertase by replacing the original solution with a narrower range of pH solution. (Between the pH range of 2~7.) In the end of this experiment we may find the exact pH range where invertase functions the best. ...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

Here's what a teacher thought of this essay

3 star(s)

This report of an investigation into the effect of pH on invertase activity adequately describes the method carried out and briefly discusses the results obtained. However, to obtain the higher grades at GCSE, the report needs to follow the tried and tested science investigation structure with sections on hypothesis, control variables, risk assessment and evaluation, all of which were missing here. In particular, practical science must start with a hypothesis, i.e. something to test, which is based on observations and prior knowledge. Similarly, an evaluation of the data collected is vital in order to assess the validity of the data, i.e. its worth so that other scientists can accept or reject the writer's findings.

3 stars

Marked by teacher Ross Robertson 10/05/2013

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

    Investigate the effect of pH on Trypsin

    4 star(s)

    pHs in-between may lead to partial denaturation. Changing the pH therefore alters the proportion of H+ ions, and hence will interfere with the electrovalent bonds and affect the three-dimensional or tertiary shape of the enzyme. Changing the pH will alter the ability of the enzyme to cleave the polypeptide chain.

  2. Marked by a teacher

    The Effect of pH on Pectinase

    3 star(s)

    If this is not controlled then the variable of enzyme concentration will not have been controlled. If there were an increased number of enzymes then the reaction would take place faster than the other reactions and I would have made the test unfair as I could not tell if it

  1. Effects of Copper Sulphate on the Activity of Catalase

    released: Time (sec) 100% H2O2 Average 80% H2O2 Average 60% H2O2 Average 40% H2O2 Average 20% H2O2 Average 10 4 3.6 3 3 3 20 5.7 4.7 3.5 3 3 30 6.8 5.1 4.6 3.7 3.3 40 7.3 6.5 4.9 4.3 3.8 50 7.8 7 5.5 4.7 4 60 8.7 7.3 5.7 5 4.5 The graph (see graph 2)

  2. Type - 1 Hypersensitivity Reaction

    When the histamine is introduced to the guinea pig ileum (tissue) the natural binding elicited a contractile response via the histamine binding onto the H1 receptors on the muscle cells in the tissue. Once more when the mepyramine was added to the tissue a contraction did not occur because of the primary binding of the histamine to the H1 receptor.

  1. The effect of enzyme concentrations on the reaction time of Urease active meal.

    3% Urease solution, I will place a clean weighing boat on a sensitive electronic balance and re-zero it. I will then transfer the solid powder of Urease active meal using a clean spatula until the reading on the balance reads 3.00 grams.

  2. The Effect of Concentration on Pectinase Using Apple

    Volume Produced (ml) 1 Volume Produced (ml) 2 Volume Produced (ml) 3 Average Volume (ml) 0 0.0 0.0 0.0 0.00 30 0.4 0.5 0.4 0.43 60 0.8 0.8 0.6 0.73 90 1.1 1.3 1.2 1.20 120 1.4 1.7 1.5 1.53 150 1.7 2.0 1.8 1.83 180 2.0 2.3 2.0 2.10 210 2.4 2.6

  1. The use of pectinase in fruit juice production

    When the meniscus of the juice was between the two markings, we took the approximate value. This in turn might not be the precise value for the reading. We only had two sets of result from the experiment. This might not give us a precise result.

  2. An experiment to investigate the effect of chloride ion concentration on the activity of ...

    If glassware is broken then it should be cleared using appropriate equipment and disposed in a designated glassware bin. First Aid: If injury occurs then a qualified first aider should treat the casualty, and an ambulance called if appropriate. ANALYSIS OF RESULTS Overview of results There is a clear trend

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