The effect of co-factor (MgSO₄) and the nature of substrate on the rate of cellular respiration in yeast were determined using two different set-ups. In the first set-up, two test tubes were used where one contains 7m and the other with 7 mL 0.2M MgSO₄ and both containing 7mL 10% yeast suspension. Here, data shows that the H₂O mixture showed higher amount of CO₂ evolved than MgSO₄.
In the second set-up, six Smith fermentation tubes were used each containing different 15mL solution (starch, lactose, sucrose, glucose, fructose or distilled H₂O). the tubes were then added with 15 mL distilled H2O and 15 mL 10% yeast suspension. Here, results show that fructose had the highest rate of respiration followed by glucose, sucrose, lactose, starch and H₂O. Thus, simpler substrate would mean higher rate of respiration.
INTRODUCTION
We all need life to survive. Life then needs energy. Cells for example need energy to build and maintain its structure, transport materials, manufacture products, move, grow, and reproduce. This is done through the process of photosynthesis which produces glucose and O₂. this then is followed by cellular respiration. In cellular respiration, O₂ is consumed as glucose is broken down to CO₂ and H₂O where the cell then captures the energy released in ATP (Campbell and Reece, 2009). It is also the process whereby fixed carbon (sugars) is catabolized to produce ATP required to drive synthetic processes, such as protein and lipid synthesis as stated by Keith Roberts (2007). Its rate will always tend to vary in response both to the supply of carbon and the demand for ATP. Respiration may either be aerobic (requires the presence of oxygen) or anaerobic where the presence of oxygen is not needed. Most cells of eukaryotic and prokaryotic organisms use aerobic fermentation. Now in the experiment, the organism to be used is yeast since it is readily handled in the laboratory.
Saccharomyces cerevisiae, a member of the Kingdom Fungi, also