• 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 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.

Conclusion

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)

    The squares of the grid are of reasonable size so that the seeds are a fair distance apart. There will thus, be reduced or no intraspecific competition giving accurate and reliable results. * Tweezers will be used to handle the cress seeds, as this is the most convenient way of clasping and moving the small seeds around.

  2. Peer reviewed

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

    5 star(s)

    a compromise, to avoid any osmotic problems that could be caused by using a concentration that was too strong. After the pilot it was predicted that it would be necessary to use a 200cm3 measuring cylinder to collect all the gas that would be produced, without having to change cylinders and risking losing some of the gas.

  1. Peer reviewed

    Effect of Caffeine on the Heart Rate of Daphnia

    3 star(s)

    However, there is a drop in the heart rate for 0.4% and 0.5% of caffeine solution. This is an anomaly shown in the experiment. Reference to other research papers and the results from other students doing the same experiment as well as consultant to experienced lecturers reveal that the

  2. Effect of Caffeine on the Heart Rate of Daphnia

    This condition is known as caffeine intoxication. It may include restlessness, nervousness, insomnia, increased urination, gastrointestinal disturbance, muscle twitching, irritability and a rapid heartbeat. Other than using Daphnia, other organisms can also be used to study the effects of different caffeine concentration on their behaviour.

  1. Rate of Respiration

    A change in pH may disrupt the optimum pH for the extracellular digestive enzymes that are used by the yeast. Hence the substrates cannot bind to the active site and form an enzyme substrate complex, causing the rate of respiration to decrease.

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

    Not all the proteins denature at the same temperature, this is why my standard deviation at 65�C is larger than at 45�C, since in some peoples beetroot almost all of the proteins in the membrane could have denatured, whereas in another people's beetroot hardly any of the proteins could have denatured at the same point.

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

    The other simple sugar in lactose is glucose. Most birds cannot digest the lactose in milk products, because their bodies cannot make the enzyme that is necessary to break lactose down into the two simple sugars. Sucrose Consists of glucose and fructose joined by a 1?-2 glycoside linkage.

  2. Investigating Respiration in Yeast

    I will measure the rate by determining how much CO2 is produced at a given time. Materials and Method Materials 10% Suspension of yeast 5%, 10% and 20% (w/v) Glucose solution Stopwatch 50cm3 Burette Clamp stand Large bowl 250cm3 Conical flask 200cm3 Beaker Rubber bung with delivery tube Thermometer Filter funnel Measuring cylinder Method 1.

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