• 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...

Introduction

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.

Middle

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 cm� beakers * 100 cm� syringe * 100 cm� measuring cylinder * flask * cork stopper with tube * rod to stir * water bath * weighing scale * weighing boat * cork stopper * 250 cm� flask * gloves * lab coat Method: * Get all the equipment ready. ...read more.

Conclusion

Place the flask in the water bath with set temperature of 37�C 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 37�C 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)

    Leave the cress seeds for 7 days. 8. After 7 days, take the petri dishes out of the Dewpoint propagator. 9. Carefully remove each seedling from the cotton pad of one petri dish, using tweezers. Place the seedlings together on an area of a clean baking tray.

  2. Peer reviewed

    Effect of Caffeine on the Heart Rate of Daphnia

    3 star(s)

    water, caffeine powder, cotton wool or gauze or muslin cloth, beakers, spatula, stopwatch, tissue paper or filter paper, electronic mass balance, scientific calculator and light microscope. Variables: 1. Manipulated variable: Concentration of caffeine solution 1.1) Manipulating the variable: Using serial dilution to prepare four caffeine solution of different concentration, that

  1. Rate of Respiration

    Hence if the lactose remains undigested, its monomers (glucose and galactose) cannot be used for the metabolic pathways in respiration, hence no C02 will be produced. Apparatus * Gas syringe * Water bath * Thermometer * Boiling tube * Measuring cylinders * Dry yeast * Substrates (glucose, fructose etc)

  2. The Effect of Different Substrates on the Rate of Respiration on Yeast (Saccharomyces cerevisiae).

    Yeasts are widespread in nature, found in the soil and on plants. Uses of Yeast Yeasts are well known for the making of bread and wine. Respiration in Yeast Yeast has to make energy, stored as ATP to carry out all cellular functions.

  1. An investigation to see whether the concentration of Sucrose effects the amount of Carbon ...

    I was able to show that as the concentration of the sucrose solution increased the amount of respiration occurring increased up until a certain point, which was 15% sucrose solution, beyond this concentration the overall mass lost decreased a tiny bit, this indicates that the amount of respiration occurring decreased.

  2. Rate of respiration in Yeast.

    it would need an ideal temperature of approximately 40-50 degrees Celsius in order to make the enzymes work effectively and so they can break down the sugars in as fast a time as possible. Safety: Keep equipment away from edge of bench, wear goggles (optional).

  1. Effect of Caffeine on the Heart Rate of Daphnia

    Examples include bacteria such as Escherichia coli and Pseudomonas fluorescens. E.coli are found in the human intestines, while Ps. Fluorescens are found in a wide range of terrestrial and aquatic habitats. According to a study using these bacteria, at a high caffeine concentration (1.0%), the growth of both bacteria is inhibited.

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

    I will calculate an average of CO2 produced from each of the 3 repeats. Degree of stirring - The degree of stirring or agitation of the flask will have to remain constant through the entire experiment, if this not done right it will result in inaccurate results, this is because

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