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

Yeast lab. Question: how does the yeast concentration affect the rate of anaerobic respiration?? Measured by the concentration of released CO2.

Extracts from this document...


Yeast fermentation experiment Design: Question: how does the yeast concentration affect the rate of anaerobic respiration?? Measured by the concentration of released CO2. Main goal (aim): tracking the relationship between the rate of anaerobic respiration and the yeast concentration. Hypothesis: Two types of cell respiration exist, aerobic and anaerobic respiration; anaerobic respiration takes place when there is no enough oxygen for the aerobic respiration, the following equation shows the aerobic respiration: Glucose yeast Ethanol + CO2 + heat. It is obvious by the previous chemical reaction that as the yeast concentration increases, so does the anaerobic respiration. Variables: Independent variable: yeast concentration (a variety of yeast solutions are used, in order to determine the effect of changing yeast concentration on respiration rate). Dependent variable: CO2 (released amounts), representing the rate of respiration. Controlled variables: Variable Why to control How to control Concentration of sucrose Because sucrose is the reactions substrate. ...read more.


Record the reading after the time has ended (the CO2 censor was calibrated at the beginning and the data collection settings was modified to collect CO2 concentration in ppm for 1 minute intervals.) - Empty the beaker and clean it, before repeating the previous procedure. - Repeat the same procedure for every concentration, 3 times for every single concentration and then obtain the average. - Record the results in a proper table. - Represent results in an explanatory graph. Data collection and processing: Raw data: Table (1): initial and final readings of CO2 evolved for every yeast concentration Concentration of yeast in solution (gm/ml) Trial (1) Trial (2) Trial (3) Initial CO2 reading (�50 ppm) Final CO2 reading (�50 ppm) Initial CO2 reading (�50 ppm) Final CO2 reading (�50 ppm) Initial CO2 reading (�50 ppm) Final CO2 reading (�50 ppm) 2% 5599 13429 7246 18353 7473 19825 4% 9637 26400 7772 22746 6949 28032 6% 8612 37908 7030 36996 7352 32248 8% 7087 37275 6860 41413 7979 39708 ...read more.


Evaluation: 1. A problem was faced in taking volumes, since cylinders were the instrument used, which is a way of error. 2. The cover provided didn't it the opening of the cylinder, thus producing errors. 3. Shaking the solution while reading, differed in the intensity, form one solution to the other. Possible improvements: 1. Use more accurate equipment (pipettes and burettes.... Etc) to take the volumes of yeasts and sucrose. 2. Use an automated machine that does vibration, to make the whole intensity of shaking equal. 3. Use containers or cylinders, which have proper openings for the CO2 sensor, to get more accurate results. 4. Use another apparatus, where the sucrose will be put into a syringe, the syringe attached to a tube, which goes through the test tube, where the yeast will be put, and the tube contains a proper opening for the CO2 reader, and then when everything is set up sucrose will be pumped by the syringe and the reaction would start. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology 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 International Baccalaureate Biology essays

  1. Marked by a teacher

    Neurology and Behaviour. Focus question: Is there an increase in the perception and ...

    5 star(s)

    (Ts-Si, n.d.a) This variance in the raising of male and females can lead to the higher disgust rating in girls as boys seem to be raised in a way in which they are more exposed to dirtier items whereas girls are usually encouraged to be clean and tidy.

  2. The effect of concentration of sucrose solution on the osmosis in potato

    Longer the time the potato exposed to air, lighter the mass of potato cylinder, as the water of potato cylinder will lose into the air. The weakness of the experiment is the human error, when measuring the volume of the sucrose solution; the beaker must be placed at the same high of human eyes.

  1. The Effect of Glucose Concentration on Anaerobic Respiration in Yeast

    On the first test I will use a 10% concentration of glucose. 6. On the second test I will use a 15% concentration of glucose.

  2. Investigating an enzyme-controlled reaction: catalase and hydrogen peroxide concentration

    Another possibility was that fluctuations in temperature caused the rate of reaction to increase or the gas inside the boiling tube to expand, forcing the fluid to rise up the manometer tube. Although minimal contact was made with the apparatus during the investigation, slight undetected variations in the room temperature may have led to inaccuracies.

  1. Yeast fermentation

    0.5g * The amount of distilled water in flasks: 200ml * The amount of water in beakers: 400ml Measurement problems It is impossible to precisely measure out the amounts of water just by an eye, even though I tried to measure the amount looking at the angle of 90 degrees.

  2. Bio lab - Oxygen Consumption in germinating and non-germinating seeds

    Final Value = 0.90 - 0.85 = 0.005 ml Actual differences in Germinating Seeds = Differences in germinating seed - differences in control = 0.050 - 0.020 = 0.030 ml Differences in Non-germinating Seeds = Initial value - Final Value = 0.90 - 0.88 = 0.020 ml Actual differences in

  1. Beet Lab. Aim: To determine the effects of temperature on the permeability of ...

    The proteins that span the membrane fall apart, creating holes in the fabric. All this combined will allow compounds to exit the cell. Higher temperature makes all molecules shake and vibrate more. The faster movement disrupts any ordered structure there might have been, eventually destroying the structure altogether.

  2. How does the salinity of water affect the germination of mung been seeds as ...

    Although plants require Na+, in excess this mineral can begin to have toxic effects on the plant that affects it capacity to germinate. Excess salt can cause ?reduced cell turgor and depressed rates of [radicle] ? elongation... Furthermore, high intracellular concentrations of both Na+ and Cl- can inhibit the metabolism

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