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

Factors affecting the activity of an enzyme

Extracts from this document...

Introduction

Introduction (Planning A) General background: In order to convert substrate into product and for a reaction to occur, enzymes must collide with and bind to the substrate at the active site. The rate at which substrates bind to their respective enzymes could be affected by a number of factors, such as the pH of the reactants, concentration of enzymes and concentration of substrates. Temperature determines the amount of kinetic energy of the molecules in a system where an increase in the temperature of a system results increases in the kinetic energy of the system. The higher the temperature of a system, the higher the levels of kinetic energy of particles, the greater the number of collisions of enzyme and substrate, thus the greater the amount of enzyme activity. However, if temperatures increase beyond certain limits (depending on the enzyme), excess heat supplied will cause the polypeptide bonds that determine the three dimensional shape of active proteins to be broken. This could lead to thermal denaturation of the protein as the specific shape of the enzyme's active site is changed and the substrate can no longer fit into it for the enzyme to function. Thus too much heat can cause the rate of an enzyme catalyzed reaction to decrease because the enzyme becomes denatured and inactive. ...read more.

Middle

Data Collection Quantity Unit Uncertainty Instrument used Temperature of hydrogen peroxide �C +/- 1 Alcohol thermometer Mass of potato sample g +/- 0.004 Electronic balance Height of foam/bubbles cm +/- 0.1 Ruler Table 1.1: Summary of quantitative data. Trial Temperature of hydrogen peroxide (�C) Mass of potato sample (g) Height of foam/bubbles (cm) 1 5 2.053 4.9 2 15 2.002 5.6 3 25 2.042 6.8 4 35 2.045 6.3 5 45 2.041 4.5 6 55 2.033 3.1 7 65 2.010 1.9 Table 1.2: Summary of results detailing height of foam/bubbles produced from approximately the same mass of potato across a range of temperatures. Regardless of the temperature at which the hydrogen peroxide samples were, all trials were observed to have a similar reaction when potato samples were added into the test-tube. Bubbles formed around the potato and the hydrogen peroxide became milky with foam; these effects were observed in a short space of time at 25�C and 35�C and longer towards the extreme temperatures of 5�C and 65�C. There were no reactions observed in the test-tubes without potato samples in the experimented range of temperatures. Data Processing and Presentation Graph 2.1: Relationship between temperature of substrate (independent variable) and height of foam/bubbles and therefore the amount of enzyme activity (dependent variable). Temperature of hydrogen peroxide (�C) Height of foam/bubbles (cm) ...read more.

Conclusion

Therefore, a better notion of total products obtained from the reaction can be explained, allowing for a more accurate comparison of evaluation of results to my initial hypothesis. With reference to Graph 2.1, the trend of enzyme activity increasing with temperature until an optimum of 25�C, only to fall rapidly at temperatures higher than this can be established. This is further substantiated by the compound percentage change in enzyme activity as seen in Table and Graph 2.2 as the percentage of reduction in the rate of enzyme activity falls with the increasing temperatures. The controls served in qualifying that as there were no reactions observed in the test-tubes without potato samples in the experimented range of temperatures, temperature is therefore deduced to have an effect on the rate at which the enzyme activity was carried out. The effects of varying temperature on the rate of enzyme activity in potato cells has been determined by measuring the amount of foam and bubbles produced and offers some insight into the amount of enzyme activity. My hypothesis that enzyme activity in plant cells would be low at temperatures lower and higher than an optimum has also been supported to an extent. This has been accomplished by varying the independent variable (the temperature of hydrogen peroxide) to influence the dependent variable (amount of enzyme activity) while maintaining the controlled variables in an attempt to make this a fair experiment. ...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

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. Browning Enzyme

    the water bath of 30�C will have the least rate of browning and so the absorbance will not be as high due to the fact that not much browning has actually taken place. Apparatus Required: Preparation - Three test tube racks - Twenty-Five test tubes - One apple - Cork

  2. Investigating an enzyme-controlled reaction: catalase and hydrogen peroxide concentration

    If no literature value then state attempts made. -The source of the literature value is fully referenced. -The results have been referred to as supporting the conclusion. -Sub-heading 'error analysis' has been included. I predict that as the concentration of hydrogen peroxide increases, the rate of reaction will increase until the pureed potato becomes saturated with the hydrogen peroxide.

  1. Influence of pH on the activity of potato catalase

    172.0 187.0 80.0 82.0 Sixth 237.0 204.0 188.0 185.0 83.0 98.0 MEAN: 216.0 175.0 168.0 156.5 68.0 75.0 Rounded to 1 decimal place Using the formula S - standard deviation ?x - sum of value x ?x2 - sum of value x2 n - number of readings I calculated Standard Deviation of time for each pH.

  2. The Effects of Salinity on Wheat Germination

    been germinated and grown in potting mix as opposed to on the paper towels also due to the fact that there may have residual chemicals remaining in the paper towel from the bleaching, most likely mild acids and tannins that may have affected germination however this was not apparent in the results.

  1. Investigating the effect of pH of Hydrogen Peroxide upon the activity of Catalase

    Then, Hydrogen Peroxide will be measured to 25 ml in a measuring cylinder and 5 ml will be poured into 5 separate test tubes, thus there will be five different measurements. Then, buffer solutions will be added to the Hydrogen Peroxide solutions in the test tubes.

  2. What is the effect of temperature on the digestion of egg-white by the enzyme ...

    celcius because it is the most efficient at that temperature (most egg digested in 30m). Also, the results suggest the enzyme begins to denature after reaching 40 degrees since its efficiency is lower than what the line of best fit predicts it to be.

  1. Experimental Question: What effect does substrate concentration have on the rate of enzyme activity?

    13.93 12.31 11.40 11.00 0% (30mL H2O) 32 32 32 32 Analysis: Sample Calculation: Calculation for Average Rate of Enzyme Activity: ? trials 4 = 4.21s + 7.39s + 2.38s + 4.12s 4 Average Rate of Enzyme Activity = 4.525s Table 3. Summary of Average Rate of Enzyme Activity by Four Different Types of Substrate Concentrations each at 4 different trials Types of Substrate Concentrations (%)

  2. Experiment-Effect of Temperature on the Action of Amylase Enzyme

    may not have been very accurate and not consistent and sometimes too long at some temperature. This also happened during the addition of hydochloric acid to stop the reaction between starch and amylase enzyme. The large and inconsistent time difference between each interval may have generalized the data too much.

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