AS OCR Biology Planning Exercise Essay Example | Topics and Well Written Essays - 1000 words

AS OCR Biology Planning Exercise - strive ExampleThe blue indicator will go colourless in the presence of active enzymes, thence indicating living cells be present and are respiring.Reagents10% suspension of barm in the instructions we were told we could pract ice rink either dried/fresh bread makers yeast. I will use fresh bakers yeast due to possible problems with dried bakers yeast e.g. clumping into grains so harder to ascertain due to dehydration.c. Prepare water bath at 20, 40, 60 and 80C (Independent variables). Its divulge to raise the temperature of the water baths gradually as a rapid increase can overwhelm the enzymes and denature them, meaning unreliable results.a. Take 1ml of the yeast solution from each test tube. Transfer the sample to ice bath. The purpose is to reduce the metabolism and reproduction of the yeast but keep them alive. Drop 1 ml of methylene blue respectively and wait for 30 seconds. (Do the same to the control and identify the existence of yeas t in the glucose solution.)All of the above procedures were used in my preliminary and the difficulty I found was in counting the yeast cells as accurately as possible with using the microscope. I later find another piece of equipment could have been used to measure the total number of cells, called a haemocytometer. I obtained the followers resultsWhat the trend shows is that as temperature increases the % of barm cells that remain active decrease. Therefore we say the two values are inversely proportional. From the point the temperature reaches 40C there is a rapid drop in Yeast viability as the enzymes become denatured and the high temperatures interefere with the shapes of the active sites. So what I can conclude is that the tempertature of participation for the main investigation is between 40C to 50C. Therefore for the main experiment I can can separate the temperature into groups 40-42, 42-44, 44-46, 46-48, 48-50. I can therefore