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

Monitoring th growth of yeast

Extracts from this document...


Introduction Yeast is a microscopic fungus, of which there are hundreds of species. It is extremely important brewing ingredient because different strains give different beer types their distinctive and characteristic flavors. When a brewery has found an ideal yeast, it will be retained for many years. However, fresh batches are produced regularly from samples kept under special laboratory conditions to prevent the built up of microbiological contamination. (Just as milk can go sour - yeast and bacteria can also contaminate beer). Individual yeast cells are invisible to the naked eye, and are carried in air current. When they grow on a suitable food source (for example fruit, such as grapes and plums) they form 'colonies' of cells. (These can be seen as a fine white powdery film on the skins of the fruit). Yeast can feed on a variety of sugars, converting them into energy in order to grow and multiply. When it first grows, the yeast cells need a supply of oxygen in the same way a animals do when they convert sugar into the carbon dioxide and energy. ...read more.


2. Secondly get a conical flask and measure 1g of yeast powder. 3. Then measure 0.5 of ammonium Sulphate, pour water into it so it reads 50ml and then put 10g of sugar in. Then mix it all. 4. After that u cover it up with cotton wool and make two more. 5. When you have all three are made make sure you cover them up with cotton wool. 6. Then you put one in a fridge (5 C), the other one in a water bath (15 C) and the last one in a room (50 C). 7. And then finally every day keep counting how many bubbles appear in 1 minute for each of the experiments. Keep repeating this process for five minutes every lesson, for a week. Safety points * Do not run around with equipment. * Do not press hard on the delivery tube as it can snap and hurt you. * If you drop any solutions in your eyes, wash it out immediately with water. ...read more.


Then the fridge temperature one was ok but the waterbath temperature one had dies on Thursday so I dint get full results fro that one. The first problem I had was when my partner made a solution but then left it at the edge of the bench and it fell so we had to make that one again. The other problem was when we were counting the bubbles my partner pressed the delivery tube to hard so is snapped and cut her hand very badly. In the future if I did this experiment again I would make sure I do it right because I no where I made the mistakes, and next time I will not make them mistakes. Conclusion Overall I think I did quite well on this experiment because the method was really easy to follow. The only thing that did not go to plan was that the waterbath temperature died. But apart from that the rest was good and I got good results. It was also quite fun when we had to count the bubbles because all different sizes kept coming out. Discussion of vocational implication ...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 Energy, Respiration & the Environment 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 Energy, Respiration & the Environment essays

  1. Marked by a teacher

    effect of temperature on the rate of respiration in yeast

    5 star(s)

    * Then I will put the live yeast collected by a syringe into a test tube. * Then I will collect hot water from a kettle into a large beaker. * Then I will use a thermometer to check the temperature and get the temperature to 60 oC.

  2. Marked by a teacher

    An investigation into the effect of different sugars on respiration in yeast.

    5 star(s)

    of glycolysis and the sugar which will have a faster rate of respiration will depend on which enzymes are in more abundance from the yeast, as there are specific enzymes for each monosaccharide. I predict that the third fastest rate of reaction will come from either sucrose or maltose, as

  1. Marked by a teacher

    Effect of nitrate concentration on the growth of Duckweeds

    5 star(s)

    The no. of fronds increases from the initial 8 fronds to an optimum average of 32 fronds, so this concentration aided the maximum growth through out investigation. As there is the correct amount of nitrates and solutes outside the root cells, this gives a favourable water potential value outside the cell.

  2. Marked by a teacher

    'An investigation into the ability of two strains of the yeast Saccharomyces cerevisiae to ...

    4 star(s)

    Equipment and materials * Ten 500cm3 flasks * Permanent marker * Digital scales * Measuring cylinder * Glass rod * Cotton wool * Thermostatically controlled incubator * Clamp stand * Burette * Funnel * Five beakers * 25cm3 volumetric pipette and filler * Pink colour chart * Carbon sources: *

  1. An investigation into the effects of temperature on the rate of anaerobic respiration of ...

    different ideas of approximation- human error as one student may measure the bubble up to the next whole number, while another student may round down. If this was the case then results would be untrue and therefore our group results combined together would be formed on the trust and believe

  2. Investigate the effect of bile salt concentration on the digestion of milk by the ...

    This makes the results obtained more accurate and thus more reliable. Other things that could affect the reliability of the data were that the class results were pooled and I had to use everyone else's result. Each group would have implemented the method differently and so this human error has

  1. Free essay

    Supporting the growth of Yeast Cultures

    * Lactose was used as a carbon source. * Sucrose was used as a carbon source. * Glucose was used as a carbon source. * Maltose was used as a carbon source. * Fructose was used as a carbon source. * Ammonium sulphate was used to provide sulphur to the culture as it is an essential compound for the yeast to be able to grow.

  2. Investigation into how Lichen growth is affected as you move further away from a ...

    I had to take into account a number of abiotic factors also when planning this investigation as this could affect the investigation. Abiotic Factors Measurement Techniques Solar Energy Input Use A Light Metre Climate Information about rainfall and temperature can be obtained from published sources Oxygen Availability Use A Oxygen

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