This problem occurred because two temperature ranges were used. Exact temperatures should have been used instead. This would have given a clearer indication of the temperatures at which the enzymes were inactive, the optimum temperature and the temperatures that resulted in denaturation of the enzymes. Theoretically, the optimum temperature of the enzymes in respiring yeast should be around 30℃ to
When the oxygen in the dough is completely used,the process of anaerobic respiration,is initiated. The initiation of anaerobic respiration in yeast is seen as the dough rising. During this experiment saccharomyces cerevisiae will be performing the initial process of aerobic respiration, to determine at what temperature baker’s yeast respires most efficiently.
Another factor that can affect the chemical reaction is temperature. It can affect the enzymes by changing their speed and at a certain temperature denaturing them.When enzymes and substrates are moving quickly, they are more likely to collide and have a chemical reaction. The warmer the temperature the faster the chemical reaction is to a certain degree. The chemical reaction was the most effective at 40 because the enzymes and substrates were moving fast, but the temperature was not high enough to denature the enzyme. After 40 degrees, the temperature increase became harmful to the chemical reaction.
Introduction - Research Question: How does the change in pH affect the fermentation of yeast and its effect on the product ethanol? Yeast: Yeast are unicellular microscopic organisms that are able to by budding and are used to convert sugars into alcohol and carbon dioxide. It is a member of the kingdom of fungi where currently there are over 1500 different species and strains of yeast. Yeast can be found almost anywhere, whether it is animals plants or soil. The cellular structure of yeast is that of a eukaryotic cell as yeast cell contains a nucleus.
The increase in collisions between the substrate molecules is due to the increase in rate. Usually the rate of enzyme catalyzed reaction doubles for every ten degree rise in temperature. Increase in temperature beyond optimum level causes a sharp decline in the rate due to denaturation of the enzyme. At around 40 degrees Celsius most enzymes have an optimum temperature and when temperatures are reduced below freezing point enzymes are inactivated but they gain their catalytic properties once the temperature is increased. Figure: (www.bbc.co.uk) 2. pH – Enzymes function most effectively over a particular pH range which is quite often a narrow range.
The activity of an enzyme is affected by its environmental factors, and any change results in an alteration in the rate of the reaction caused by the enzyme (2). Naturally, the enzymes are adjusted by producing optimum rates of reaction or they adapt to function well in extreme conditions (2). Temperature, pH, and enzyme and substrate concentration all affect enzyme activity. The rate of reaction of an enzyme catalyzed reaction is affected by the difference in enzyme and substrate concentration. Increasing substrate and enzyme concentration will increase the rate of the reaction because more substrate molecules will be colliding with enzyme molecules, resulting in products being formed (1).
Change in temperature The reaction rate of enzymes is affected by temperature, as do pH, substrate concentration and enzyme concentration. At low temperature the enzyme activity is low. As the temperature increases the rate of reaction increases,usually 2-fold for every 10 degree Celsius elevate. Effect of Temperature on Enzyme Action. (2018).
Amylase increases the rate of reaction by decreasing the activation energy needed to hydrolyse the starch molecules. These enzymes have a secondary and tertiary structure and this could be affected by increases and decreases in temperature beyond the optimum temperature of the enzyme to work in. Mostly enzymes are highly affected any changes in temperature beyond the enzymes optimum. There are too
This energy meets the needs for growth and maintenance of internal functions. Under anaerobic condition, yeast switches to fermentation which utilizes only about 5% of the energy contained in glucose and ethanol as the end product is produced. Acetic acid bacteria convert glucose to produce gluconic acid and ethanol to produce acetic acid giving it a sour flavor. The acetic acid production in turn induces the yeasts to produce ethanol and making alcohol available to bacteria. Both ethanol and acetic acid possess antimicrobial properties and thereby act against pathogenic bacteria and prevents contamination of the tea fungus (Liu et al., 1996).