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

Potato Discs - investigate how the number of potato discs and therefore the surface area of the potatoes affect the amount of oxygen produced when in a reaction with hydrogen peroxide,

Extracts from this document...


Biology - Potato discs experiment Aim: To investigate how the number of potato discs and therefore the surface area of the potatoes affect the amount of oxygen produced when in a reaction with hydrogen peroxide, Apparatus: * 1 Measuring Cylinder, 25cm3 (to measure out hydrogen peroxide in) * 1 Boiling tube (to place potato discs and hydrogen peroxide into) * Cork borer (to cut out a piece of potato from the whole potato) * 1 Timer (to count to 3 minutes to see how much oxygen and water goes through to the delivery tube) * Beaker (to put water into) * 1 30cm ruler (to measure length of potato discs) * 1 Potato (used instead of catalase to see difference in volume) * 1 M Hydrogen Peroxide Solution (used as the solution to react the enzyme catalase as it acts as substrate for the potato to react with) * Scalpel (to cut potato discs) * Delivery Tube (to transfer oxygen and waste produced to boiling tube) * Bung (to ensure that no water or oxygen escape from the delivery tube) * Tile (to cut potato discs on with a scalpel) Safety In this experiment it is essential that you wear safety goggles as goggles will prevent any chemicals or solution from entering your eyes, this is a precaution in case something goes wrong in the experiment and the solutions splash towards your eyes. ...read more.


Control Variables: Hydrogen Peroxide volume and concentration These affect the rate of reaction as when there is more substrate concentration (Hydrogen Peroxide) there is an increase in the rate of reaction. For this reason I aim to control the substrate concentration by using the same quantities and concentration of the substrate Hydrogen Peroxide for each different experiment with different amounts of discs. pH level: It is essential to control the pH level as a change in pH would affect the ionic and hydrogen bonding in an enzyme and so it would alters its shape and its active site so the reaction may not be catalysed. Every enzyme has an optimum pH at which its active site best fits the substrate and the reaction is catalysed. Difference either side of the optimum pH, results in unwanted conditions of the enzyme and a slower rate of reaction, which would make my results unreliable if this was different in every reaction, for this reason it is essential that I control this variable. To control this in my experiment I will use potato discs from the same potato this means the pH level will be controlled as the same potato throughout on average will have the same pH, also the same quantity of Hydrogen Peroxide was used for each experiment. ...read more.


Moreover, If I was to do the experiment again I would measure the potato pieces using a micrometer, this would provide a more accurate sized piece of potato and this would mean a much more accurate set of results. Additionally, if I was to redo this experiment I would also repeat each experiment, as I only did one experiment for each number of potato discs however, if I was to do more repeats I would have a better average as I would have more results and therefore my results would be more reliable. Despite these minor mistakes I am confident in my conclusion as most of my results follow a pattern and the procedure in which the experiment was taken out, is pretty accurate. Finally, the potato discs may have stuck to each other, blocking one of the ends from releasing enzymes, this means that a full reaction may not occur and I will not get accurate results due to this, so if I was to redo this experiment I would ensure that the potatoes are touching each other as little as possible. All in all, from this experiment I have learnt that an increase in the number of potato's, and therefore an increase in surface area (an increase in the enzyme catalase) there is more gas and water produced ?? ?? ?? ?? Kastriot Jonuzi ...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 Energy, Respiration & the Environment 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 Energy, Respiration & the Environment essays

  1. Marked by a teacher

    Fighter Pilot A Statistical Analysis of Reaction time and its Correlation with Dominant ...

    5 star(s)

    Then in between each ruler drop the participant should clench and tense arm and fist for five seconds. This arousal of the muscles should promote a heightened response. A quite empty room should be reserved to prevent any distractions and the experiment to be held over the course of a

  2. Marked by a teacher

    Effect of nitrate concentration on the growth of Duckweeds

    5 star(s)

    And so a smaller frond meant less photosynthesis and energy provided for the plant to grow so this is a limitation to the equality in growth. Another limitation was that the thickness in rootlets of the duckweeds was not considered, as they were too tiny to be able to measure with a ruler.

  1. the effect of bile concentration on the activity of the enzyme lipase during the ...

    Risk Assessment * Sodium hydrogen carbonate is an irritant and can cause severe irritation if contact it made with skin or eyes, therefore whilst handling this chemical gloves, goggles and a lab coat should be worn at all times. If contact is made with skin or eyes then rinse the place of contact with cold water for several minutes.

  2. Field trip report Mangrove ecosystem

    3 to 4cm board, it has salt glands to remove excess salt absorbed, thus can survive in seawater. Flowers: White and small, appear in dense clusters, with 5 partly fused petals, pentamerous in shape, pointed in bud with 1 to 2 cm long.

  1. out how different concentrations of the enzyme pectinase affect the degradation of the substrate ...

    This breaks the hydrogen bonds holding the molecules in their shape and so altering the three-dimensional shape of the pectinase molecules to such an extent that their active sites no longer fit the pectin molecules. This would denature the pectinase and result in the lowering of the rate of juice flow.

  2. Investigating how prolonged exposure to its optimum temperature affects the respiration of yeast.

    This is where the respiration will take place. The delivery tube will be connected directly to the conical flask and will lead to the inverted measuring cylinder. Bung 1 Used for concealing the yeast and glucose together, so no Carbon Dioxide is released into the atmosphere, and goes straight up the delivery tube and into the measuring cylinder.

  1. To investigate how concentration of the enzyme catalase in celery extract affects the rate ...

    Material from - http://s-cool.co.uk The pH must be correct for each enzyme, because if the conditions are too alkaline or acidic then the activity of the enzyme is affected. This happens because the enzyme's shape, especially the active site, is changed. It becomes denatured, and cannot hold the substrate molecule.

  2. Investigate the effect of bile salt concentration on the digestion of milk by the ...

    the breaking or formation of bonds, ultimately helping the enzyme's main job of catalysing the reaction. Milk: Milk is an emulsion that is full of nutrients that is secreted by a female mammal. An emulsion is two liquids or a liquid and a solid that are not soluble in each other and so form droplets.

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