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

What factors could have an effect on the rate of respiration in yeast?

Extracts from this document...


What factors could have an effect on the rate of respiration in yeast? There are many factors that could affect the rate of respiration in yeast. Such as the temperature the yeast respires at as at different temperatures the enzymes in yeast work faster or slower at breaking down the glucose this is because the yeast enzymes will have more or less energy with which to break down the glucose. The amount of yeast will also have an effect on the results, as if we are to use different amounts in each experiment it will form an unfair test. Another factor that could affect our investigation is the percentage of glucose in the yeast. I must also make sure to leave all experiments undisturbed during the course of respiring, this means they cannot be stirred or let air get to them. I have chosen to investigate the affect the percentage of glucose concentration has on the rate of respiration in yeast. I will use an experiment to determine whether the yeast's rate of respiration will be quicker, slower or if it does not change when the percentage of glucose concentration in it is varied. ...read more.


Each experiment will be repeated a second time so as to find any anomalous results and if any are found that experiment will be repeated once more to verify the correct result. When dealing with yeast and alcohol I must make sure not to inhale or consume in any way anything during the experiment as a lot of it may be harmful in someway. Also if any glass is broken for any reason it must be cleared up properly and safely. I found some secondary information on the Internet and put it together with some of my background knowledge to form the following information. FERMENTATION is the breakdown of sugars by bacteria and yeast using a method of respiration without oxygen (anaerobic respiration). It involves a culture of yeast and a solution of sugar, producing ethanol and carbon dioxide with the aid of the enzymes. This is an 8-10 step process requiring different enzymes each time, but it can be simplified like this. All the ENZYMES are protein chains of amino acids. They exist in the form of helix structure with hydrogen bonds holding the pitches together. On the amino acid molecules, there is R a group. They react with each other to form peptide bonds, transforming the chain into a 3-dimensional structure. ...read more.


The rate of reaction table could be seen in the obtaining evidence along with the other results. The formula for calculating the rate of the reaction is: The change in volume of carbon dioxide (y) The change in time per minute (x) It is a shame that I did not have enough time to do the rest of the experiment such as the sugar concentration of 50% because I do not have enough time to complete it. Though I have not done the other experiments I still have enough of the results to conclude the experiment. Although I did not do 50% sugar concentration I could still say that the best sugar concentration will still be 100% because it has the nearest osmotic pressure on both the solution and the yeast cells. The main conclusion here is that the most important factor is the osmotic pressure that effects the whole experiment. Due to my prediction what I have predicted was nearly all right except on which was that the amount of carbon dioxide given off will increase as the concentration of sugar increase was wrong because that it is exactly the opposite. Except that the other prediction is the same as the result. ...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

    Investigating respiration of maggots

    5 star(s)

    maggots in the boiling tube To ensure the experiment is fair I will allow the maggots time to acclimatise to the new environment. I will then take readings for several minutes and then repeat each temperature twice. This will enable me to account for any anomalous results I may acquire during the experiments.

  2. Marked by a teacher

    The Effect Of Temperature on the Respiration Of Yeast.

    5 star(s)

    After the pyruvate is decarboxyilated it is then dehydrogenated and then combined with Coenzyme a to form acetylcoenzyme A (AcoA). pyruvate (3C) + coenzyme A Carbon Dioxide acetyl (2C) coenzyme A NAD NADred Coenzyme A consists of adenine, ribose and pantothenic acid.

  1. Marked by a teacher

    An investigation to see how different sugars affect the growth and respiration of yeast.

    3 star(s)

    Start the stop clock 11) Time how long it takes for the solution to go colourless. This is to show whether the solution is active or not. 12) Stop the clock after 10 minutes and record the results, even if the solution remains blue.

  2. Investigation to find the effect of glucose concentration on fermentation of yeast.

    removed from the culture and it can be checked later after one has concentrated on the cell count. 6) Water bath This is to keep the solution at a constant temperature and to optimise the temperature for of the yeast cells to reproduce so that the limiting factor is the glucose concentration.

  1. Affect of sucrose concentration on the rate of respiration.

    will mean that all the solution will be kept at a constant temperature. I also propose to use a measuring cylinder for measurements at will allow me to correctly see that the level is correct as the meniscus will not be over the mark.


    Since the concentration of H+ is higher in the intermembranal space, an electrochemical gradient exists. Therefore H+ diffuses down their concentration gradient through the ATP synthase enzyme releasing energy. The energy is used to synthesise ATP by phosphorylation, i.e. adding Pi to ADP.

  1. Investigation into the Effect of Temperature on the Rate of Fermentation by Yeast.

    4. Every 30 seconds, the volume of CO2 in the gas syringe was recorded. 5. The experiment continued for 20 minutes. 6. The results were recorded in Tables 2-6. Fig 2. Results Temperature / oC Original volume in gas syringe / cm3 0 1.5 15 1 30 1 45 4 60 4 Table 1.

  2. Catalyse Investigation

    * Half fill another test tube with a 4% starch solution. * Cool both test tubes and maintain at 10OC * With a pipette place a drop of iodine into each dimple in a dimple tray. * With a glass rod lift a drop of the starch solution from the

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