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

Investigation of the effect of temperature on the rate of respiration of yeast.

Extracts from this document...

Introduction

Investigation of the effect of temperature on the rate of respiration of yeast Introduction The aim of this investigation is to determine the effect of temperature on the rate of respiration of yeast. The temperatures at which the culture was tested at were 20�C, 30�C and 40�C to give a range of rates of respiration which can be compared. The yeast cultures were maintained at these temperatures using a water bath as water has a high specific heat capacity and thus maintains a specific temperature relatively well. As a result of preliminary studies into the topic, the hypothesis was made that 'as the temperature increased, the rate of respiration would also increase in the yeast.' This is because the reactions that occur in respiration are enzyme catalysed. Therefore, we can deduce that any reaction where enzymes are present will have an optimum temperature at which the rate will be at its optimum. This is likely to be around the 30�C - 40�C. For example at the very first step of respiration in glycolysis, the enzyme phosphofructokinase is used to phosporylate the glucose so that it can be split into to two triose sugars that will eventually produce a pyruvate molecule each. When these pyruvate molecules enter the Kreb Cycle and is converted to acetate, coenzyme A combines with this new compound to assist in the formation of oxaloacetate. ...read more.

Middle

Just how much will a small change in temperature affect the Rate? If a reaction has an Activation Energy of 50 kJ/mole what effect on the Rate would a change of temperature from 20to 30oC? 1. Convert the two temperatures to Kelvin: T1 = 20+ 273 = 293 K T2 = 30+ 273 = 303 K 2. Plug in Activation Energy, T1,T2, and R = 8.31 J/mole-K into the Arrhenius Equation. ln (k2/k1) = [(50000 J/mole)/(8.31 J/mole K)](1/ 300 K - 1 /310 K) ln (k2/k1) = 0.647 k2/k1 = e0.647 = 1.91 Note that a 10 oC change in temperature results in an approximate doubling of the reaction rate which is known as the Q10 rule and it can be predicted to be the case in this reaction also. An actively respiring yeast culture will be placed in water baths at different temperatures and the rate of their respiration measured using a manometer and recording how much the fluid moves from its initial position after a time interval of five minutes. This will indicate how much gas is produced by the respiring yeast every five minutes at different temperatures. The rate of respiration can therefore, be calculated from these observations for each temperature and then compared to identify any trends. ...read more.

Conclusion

When these pyruvate molecules enter the Kreb Cycle and is converted to acetate, coenzyme A combines with this new compound to assist in the formation of oxaloacetate. Decarboxlases and dehydrogenases are also used in the Kreb Cycle. Then in the last stage of oxidative phosphorylation cytochrome reductase and cytochrome oxidase are used. Thus, as a result of all these enzyme catalysed reactions, the temperature will be a limiting factor and as the rate increases the most between 30�C - 40�C it can be said that the enzymes involved have their optimum temperature within this range. The prediction was also made that as the temperature increased 10�C the rate would double as a result of the Q10 theory. The experiment showed that this was not exactly the case as the rise of temperature from 20�C to 30�C resulted in an increase in rate by a factor of 1.68 and an increase in temperature from 30�C to 40�C yielded a rate increase by a factor of 1.34. although this is not a consistent factor of two that is being shown, its can be roughly approximated as such. This is significant because the Q10 rule is applicable under ideal condition that were too difficult to obtain in a college laboratory and thus discrepancies are noted. ...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. How temperature affects the rate at which bread dough rises and find out the ...

    to explain the rates of reactions and they suit all above stated variables; in different ways. -The kinetic theory Explains that heat give up more energy to particle so they collide more often therefore more successful collisions and the more successful collisions the faster they mix so less time is

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

    8.7 120 8.2 7.9 7.7 7.9 150 7.8 7.8 7.6 7.7 180 7.5 7.7 7.5 7.5 210 7.3 7.6 7.4 7.4 240 7.1 7.5 7.3 7.3 270 7 7.4 7.2 7.2 300 7 7.4 7.2 7.2 Analysis When recording my results, I decided to present a reading every 30 seconds, until 5 minutes.

  1. Investigate the rate of a catalysed reaction, when altering the temperature of the solution ...

    These reactions can take place in test tubes but very slowly, unless pressure and temperature are raised very high. Living cells try to avoid high pressure and temperatures and so they speed up the reaction with the use of special chemicals called enzymes.

  2. To investigate the effect of varying the masses of white sugar and yeast and ...

    During the process of dough rising the carbon dioxide goes into solution until the solution is saturated and then any more which is generated makes its way into the nitrogen gas bubbles which grow in size and the dough expands.

  1. An investigation into the effect of temperature on anaerobic respiration in yeast.

    I will do this so that the results are fair and the suspension gets a chance to become the same temperature as its experimental atmosphere no matter what temperature is used. I will also put the same amount of suspension in each fermentation tube.

  2. An investigation to establish how concentration of substrate effects the rate of anaerobic respiration ...

    At this instance start the timer. 8. NB all of the above should where possible occur in a temperature control bath and where not possible the apparatus must be only away from the bath as long as necessary. 9.

  1. Find out how the rate of hydrolysis of an organic halogen compound depends on ...

    Example 4 - the reaction of propanone with iodine This reaction is catalysed by acid, CH3COCH3(aq) + I2(aq) acid catalyst CH3COCH2I(aq) + H+(aq) + I-(aq) The rate equation found by experiments is, rate = k [CH3COCH3] [H+] (Notice that the acid catalyst, H+, appears in the rate equation even though it is not used up).

  2. Null hypothesis:The type of sugar will have no effect on the rate of respiration ...

    During a reaction the substrate will bind to the active site of an enzyme this will only occur if it is given some extra energy referred to as activation energy, in order to start the reaction. In order for a reaction to take place the substrate needs to collide with

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