ANAEROBIC RESPIRATION IN YEAST
The aim of the experiment was to see which types of food respire the most efficiently.
Bacteria and yeast have been used for thousands of years in the preparation of food such as bread, cheese, yoghurt, alcoholic drinks and vinegar on a much large scale yeast is used to make ethanol. Many of these foods are products of anaerobic respiration Yeast uses anaerobic respiration because there is limited oxygen available. Yeast is used for industrial processes like the fermenting of spirits wines and bears and in baking bread so it would be of great benefit to the brewers and bakers if they knew under what factors yeast would work most efficiently. Glucose is used by the yeast to release energy in anaerobic respiration glucose ethanol+ carbon dioxide + (energy released). glucose → lactic acid (+ little energy)The breakdown of glucose to produce carbon dioxide and water is catalysed by enzymes who are biological catalysts that speed up the rate of reaction. The active site of an enzyme is specific to the shape of the substrate molecule. In this case glucose. The reason in our experiment that the test tubes are placed in water at approximately 30 degrees is because that is the enzymes optimum temperature if the temperature is below that reactions are less likely to occur but if it is too far above that the enzymes active site is changed so the molecules it catalyses can’t fit into the active site. The rate of reaction falls to zero as the enzyme is de natured by the high temperature .
Yeast does not respire using oxygen this means that it performs anaerobic respiration. The other form of respiration is aerobic respiration this is when glucose is broken down using oxygen, This is the form of respiration that normally takes place in humans and animals. The reason the yeast breaks down the glucose is to release energy it uses for further growth. Sucrose is made up of glucose. The sucrose must be...