Aim: To identify the products of anaerobic respiration in yeast
Apparatus and Materials: boiling tubes, delivery tube, bungs, sugar, yeast, lime water, liquid paraffin, Bunsen burner
Procedure: Water was first boiled in the boiling tube. A small amount of sugar was then dissolved into the boiled water, which was allowed to cool. A little bit of yeast was added then stirred. Apparatus was set up as shown in Figure 4. A layer of liquid paraffin was added to the surface of yeast/sugar mixture using the pipette. The apparatus was left in a warm place for a day and observations were made.
Observations/ Results: It was observed that after sometime, air bubbles arose and turned the lime water into milky precipitate showing that the air evolved was carbon dioxide. When the rubber bung of the test tube containing sugar and yeast was removed, the smell of alcohol was observed.
Discussion: Respiration is a series of metabolic reactions occurring on cellular levels and releasing energy from organic material. Anaerobic respiration is cellular respiration that occurs without oxygen. The process of anaerobic respiration begins with the breaking down of glucose that produces pyruvic acid. The pyruvic acid then undergoes a fermentation process to produce ATP, which cells employ for energy production. In this lab, anaerobic respiration in yeast was experimented. The formula for anaerobic respiration in yeast is C6H12O6 energy+ 2C2H5OH+2CO2. Yeast is a single celled fungus containing a number of enzymes useful during fermentation such as zymase. Zymase is an enzyme that catalyzes the fermentation of sugar into ethanol and carbon dioxide. Yeasts are eukaryotic micro-organisms classified in the Kingdom Fungi. The liquid paraffin added to the surface of the yeast and sugar mixture was to prevent oxygen from entering the mixture since we know that anaerobic respiration is a type of respiration that occurs without oxygen. The sugar in the solution