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

Investigation to discover the effect of temperature on anaerobic respiration in yeast cells.

Extracts from this document...

Introduction

Muhammad Versi GCSE Coursework BIOLOGY Investigation to discover the effect of temperature on anaerobic respiration in yeast cells. Introduction Yeast is a single-celled fungus consisting of millions of tiny living cells. Each cell contains a cell wall and oil granules & glycogen that store carbohydrates and lipids. 19.7(a) A yeast cell ribosome droplet membrane Yeast cells feed on a sugar using an enzyme to break it down into ethanol and carbon dioxide. This process is called fermentation or anaerobic respiration. The equation for anaerobic respiration is: Enzymes in yeast Glucose ???? Ethanol + Carbon Dioxide + Energy C6H12O6 ????? 2C2H5OH + 2CO2 + Energy Yeast is usually grown in a solution containing carbohydrates, the yeast pour out enzymes that break the carbohydrates into glucose that is absorbed by the cell. Enzymes are used in living organisms to increase the rate of a reaction such as digestion. A chemical reaction involving an enzyme always involves one substance being changed into another, the initial substance is called the substrate and final substance is called the product. Enzymes have a very precise shape that usually has a dent, this shape is exactly the right size to fit into the substrate molecule. The dent is called an active site. Each enzyme is The substrate slots Designed so that Thetrate molecule Fits exactly into the It. ...read more.

Middle

Once temperatures reach around 50 degrees the enzyme starts to lose its shape and become damaged, this means it cannot catalyse as well so the reaction slows down. If the temperatures increase it eventually becomes denatured and the reaction will stop completely because the enzymes are inactive. If the reaction is below 25 degrees the enzymes will not have enough energy to move around and catalyse substrate molecules, therefore the reaction will slow down at temperatures lower than 25 degrees. I also predict that if the temperature is over 50 C or under 10 C the respiration rate will be slow and take too long for any measurements to be made. This is because enzymes lose their shape if the temperature is too high and become inactive or denatured if it is too low. However I will investigate temperatures above 50 C and below 10 C to be more reliable and accurate in this prediction. Method For this investigation I will use the following set of apparatus: * Delivery Tube * Thermometer * Boiling Tube (with yeast suspension) * Plastic Beaker * Wooden Peg * Pointed Glass Delivery Tube * Test-Tube * Janus Green & Hydrogen Carbonate Indicator & Liquid Paraffin * Timer * Test tube rack Peg Delivery Tube Pointed glass Delivery tube Plastic beaker to act as water bath Test tube Boiling tube with yeast suspension For the investigation I will fill two thirds of ...read more.

Conclusion

Two is a low number for this type of experiment and if my prediction for temperature of enzyme activity is right then four must be one of the highest number of bubbles I should expect to see. Therefore I must increase the time allowed for counting bubbles otherwise there will be a very limited range and the results will be unreliable and inaccurate. I have decided to increase the time allowed for counting bubbles to a minute but not more because the experiment will take too long especially if I am to carry it out three times for each temperature. To make up for lack of bubbles and rate of respiration I have decided to increase the glucose concentration to 20% hoping that this will affect the rate of respiration and the amount of bubbles. My preliminary experiment also helped me to decide other factors such the time to equilibrate and the temperature range. With the lack of bubbles the results will not be so clear and exact so I have decided to limit the range slightly, the temperature range will be form 10C to 80C with measurements made every 10 degrees. I have kept the temperature range quite wide for reliability and for extra support to the conclusion. The preliminary experiment also helped me to understand how to set up the experiment most efficiently and also clarified a few points on the experiment that I was initially unsure of. ...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

    The Effect Of Temperature on the Respiration Of Yeast.

    5 star(s)

    Oxidation has taken place and the NAD is then said to be reduced to NAD + H+. This reduced NAD changes the colour of the TTC solution from colourless to pink. NAD is called a coenzyme, a non-protein organic compound essential for the functioning of the association enzyme.

  2. Marked by a teacher

    Investigating the Effect of Ethanol Concentration on the Rate of Respiration in Yeast.

    3 star(s)

    There are enzymes used in respiration, for example Acetyl Coenzyme A, which is involved in the Krebs Cycle. Enzymes adhere to a Lock and Key Theory, in which the enzyme and the substrate fit perfectly (the active site). Yet, the enzyme having an inhibitor attached to it at one part

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

    The highest Glucose concentration was the quickest. Apparatus, equipment What I will be using for my investigation Why I will be using them. 4-cm3 1.0M glucose solution To see how this different glucose concentrations effects the fermentation of yeast. 4 cm?

  2. Investigate how temperature affects the rate of anaerobic respiration in a sucrose & yeast ...

    Record results. 8. Add beaker of cold water, stir, retake temperature and record. 9. Place new syringes in container and time as before. 10. Count and record number of bubbles CO2 produced from each syringe. 11. Repeat steps 8 - 10 five times, adding more cold water each time

  1. WHAT EFFECT DOES SUBSTRATE HAVE ON THE RATE OF RESPIRATION IN SACCHAROMYCES CEREVISIAE?

    * Isomerase - an enzyme which catalyses the conversion of one isomer into another, i.e. fructose into glucose. In respiration, the main respiratory substrates are carbohydrates (specifically glucose) which are oxidised to release energy. Therefore it is vital that the saccharomyces cerevisiae contains carbohydrase enzymes to digest large carbohydrates into smaller monosaccharides.

  2. An investigation to find the lowest temperature that kills all the yeast cells in ...

    Results Temperature/ �C Alive or dead??? 35 Alive 40 Alive 45 Alive 50 Dead 55 Dead 60 Dead 65 Dead 70 Dead Conclusion Based on these results, to the nearest 5 �C, it appears the respiratory enzymes denature at 50 �C resulting in the death of the fungi.

  1. Investigating the Effect of Temperature on Rate of Respiration in Yeast

    After that it is combined with coenzyme A to produce acetyl co enzyme A. [Biology 2 book]} The Krebs cycle is also known as the citric acid cycle, and it also occurs in the matrix of a mitochondrion. Oxygen is not required for this pathway, but it is part of

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

    Substrate concentration - at a low substrate concentration there are many active sites that are not occupied. This means that the reaction rate is low. When more substrate molecules are added, more enzyme-substrate complexes can be formed. As there are more active sites, and the rate of reaction increases.

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