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

The effect of substrate of yeast fermentation and its respiration rate

Extracts from this document...


The effect of substrate of yeast fermentation and its respiration rate. Aim: The aim is to measure the amount of carbon dioxide bubbles produced by three different respiratory substrates; glucose, sucrose and starch that are acted upon by yeast. To determine, which substrate produces the most amount of bubbles. I will carry out this experiment by reacting yeast with the three different respiratory substrates at constant temperature, pH, mass, volume and other variables and I will measure the rate of respiration. I will add each respiratory substrate sugars with yeast and that will produce alcohol, carbon dioxide and energy and I will measure the rate at which most bubbles are produced for each sugar. Yeast + Respiratory Substrate Bubbles (CO2) + Alcohol + Energy Prediction: I predict that when glucose reacts with yeast it will produce most amount of bubbling than sucrose and starch and therefore the rate of respiration of glucose with yeast will be higher than with sucrose and glucose. ...read more.


Starch is a polysaccharide which consists of many units of glucose linked together by a glycosidic bond. It is a long chain of molecules and branched molecules. * This is a polysaccharide which has many units of glucose linked together. It is a very compact structure therefore hard to breakdown. It is difficult to break down all these glycosidic bonds and the structure is very compact. Therefore starch will have the lowest rate of respiration and will produce least amount of bubbles. Glucose is a simple molecule, a monosaccharide so it is easy to break down and therefore it will have the highest rate of respiration. Alcohol will be produced much quicker and more bubbling will be recorded. Equipment: * Respiratory substrates (glucose, sucrose, starch) * Yeast * Distilled water * Measuring cylinder * 3 Test tubes * 100 cm³ beakers * 100 cm³ syringe * 100 cm³ measuring cylinder * flask * cork stopper with tube * rod to stir * water bath * weighing scale * weighing boat * cork stopper * 250 cm³ flask * gloves * lab coat Method: * Get all the equipment ready. ...read more.


Place the flask in the water bath with set temperature of 37ºC for 10 minutes. Then as the bubbling starts immediately place the cork stopper onto the flask. Measure the volume of gas produced. * Repeat the same procedure for test tubes B and C. * Repeat the same procedure for sucrose and starch. * Take the readings. Fair test: To ensure that the experiment is fair there are certain variables that must be kept constant. Temperature and pH must be constant in order to obtain accurate results. To keep the temperature constant I will use the water bath to maintain the temperature of 37ºC as this is the optimum temperature for the enzymes to work at its best. I will use the buffer solution to monitor the pH value. I will ensure that I use the same measuring cylinder and same volume of yeast and sugars to maintain the accuracy. I will repeat the experiment three times for each sugar to increase the degree of accuracy. Resources: http://www.scientificpsychic.com/fitness/carbohydrates.html http://en.wikipedia.org/wiki/Sucrose http://www.scientificpsychic.com/fitness/carbohydrates1.html Essential AS Biology for OCR, Glenn and Susan Toole, nelson thornes pages; 28, 30. 1 ...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 Exchange, Transport & Reproduction 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 Exchange, Transport & Reproduction essays

  1. Marked by a teacher

    Biology coursework planning - the effect of lead chloride on the growth of cress ...

    5 star(s)

    This in turn, increases the reliability of the results. * The biomass of the cress seeds will be determined as an indication of the amount of growth in the different concentrations of lead chloride. This is has been discussed before; the reason being that measuring the length of the shoots does not take into account, lateral and root growth.

  2. Peer reviewed

    "An investigation into the Respiration of Carbohydrate Substrates by Yeast."

    5 star(s)

    However, it can easily be broken down to produce simpler carbohydrates by a hydrolysis reaction via the enzyme zymase produced by yeast. It is broken down firstly into maltose then into glucose then into carbon dioxide and ethyl alcohol. In this experiment we used two different types of the Saccharomyces Cerevisiae ('saccharo' meaning sugar and 'myces' meaning fungus)

  1. Peer reviewed

    Effect of Caffeine on the Heart Rate of Daphnia

    3 star(s)

    Problem Statement: What is the effect of caffeine on heart rate of Daphnia (water flea)? Hypothesis: There is a correlation between concentration of caffeine solution and the heart rate of Daphnia (water flea). In this experiment, when the concentration of caffeine solution increases, the heart rate of Daphnia (water flea)

  2. Effect of Caffeine on the Heart Rate of Daphnia

    This shows that caffeine also exhibits antibacterial properties. Anatomy of Daphnia 1.2 Problem statement: How does the concentration of caffeine solution affect the heart rate of Daphnia? 1.3 Aim: To determine the effect of concentration of caffeine solution on the heart rate of Daphnia.

  1. Investigate the effect different concentrations of glucose in a yeast & Glucose solution has ...

    Method Make sure the environment is safe to perform an experiment. Do this by clearing the working surfaces of obstructions and making sure the area around your feet is tidy. It is also necessary to wear safety glasses for the duration of the experiment.

  2. Affects of Alcohol on the Body & Fermentation

    These are bottom and top fermentation. Bottom fermentation produces a pale coloured beer, often lighter and contains fewer units of alcohol. These characteristics are developed when yeast is injected at lower temperatures, between 6-8 degrees, and left to mature at zero degrees.

  1. Design an experiment to investigate the effect of temperature on the movement of a ...

    When the hydrogen bonds break it causes the structure to change, therefore they do not fit into the same space that they used to. This means that they could have allowed the anthocyanin pigment to diffuse through the membrane, or there could have been larger gaps in the membrane, if the proteins were a smaller shape.


    Put them back into the water bath. 5.) Record the height of the bubble every two minutes, of each test tube. Do this until the reaction is complete i.e. the bubble would not get any larger. 6.) Repeat this for the next substrate and so on.

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