Fermentation process involved chemical changes in organic substrate through the action of enzymes and defined as the extraction of energy from carbohydrates in the absence of oxygen. In food processing and production, it is the activity of microorganisms that brings a desirable change to food or beverage. Alexa M. Madriaga published an article entitled “Enzyme Kinetics in S. cerevisiae” focusing on measuring the amount of carbon dioxide produced in fermentation reactions using different proportions of sugar and yeast and the rate of reaction. This paper discussed the content of the article based on the presented methods and data.
In order to meet the purpose of the study, the specific analyses that were considered include: (a) evaluating how the dependent variables (sugar and yeast concentrations) will affect the amount of produced carbon dioxide as well as its effect in fermentation rates; and (b) determining whether or not essential oils will hinder the fermentation rates and its influence on the rate of reaction and carbon dioxide production. The following process were conducted to draw the conclusion. The materials were prepared and experimental set up were arranged. Water displacement vessel was made by utilizing mason jar (for reaction vessel) and water bottle (gas chamber). This set up is used to measure the carbon dioxide produced after some time. There are five trials in total and each trial, varying proportions of sugar and yeast is applied and the last two trials include the addition of essential oils (lemon in trial 4 and peppermint in trial 5). One cup of lukewarm water was used in each proportion. The sugar was first dissolved followed by the yeast; the solution was agitated to activate the yeast. Set of trials include (1) 2tbsp sugar, 1tsp yeast; (2) 2tbsp sugar, 2tsp yeast; (3) 1tbsp sugar, 1tsp yeast; (4) 2tbsp sugar, 1tsp yeast, ½ tsp lemon; (5) 2tbsp sugar, 2tsp yeast, ½ tsp pepper mint. The decreased amount of water in the gas chamber indicates the amount of gas produced after 24 hours. The reaction was monitored, and data and observations were recorded. After 24 hours, the resulted net amount of carbon dioxide (in mL) produced in trials 1, 2, 3, 4, and 5 are 3844, 4566, 1710, 4109, and 4406 respectively. The rate of reactions in mL per second are 0.1114, 0.1056, 0.0749, 0.1081,0.1037 in each trial respectively. From the results, the paper concluded that the concentration of sugar does not affect the amount of produced carbon dioxide but rather the amount of added yeast in the solution.
First, the paper conducted a good set of trials by examining different proportions of yeast and sugar to determine its effects on the fermentation reaction, carbon dioxide production, and rate of reaction. The procedure is well explained but I suggest to explain further how to set up the main equipment which is the water displacement vessel, and include alternative if there is. While I was reading the paper, I am thinking about other parameters that they should consider including temperature because I think it will have an impact in the experiment because the initial temperature of the water is lukewarm and this should be held constant to have a more accurate result, it’s a good thing that this recommendation is included in their conclusion and summary. The clarity is there especially when S. cerevisiae is defined at the first part of introduction, this will help the reader imagine or understand what it is and will be able to grasps the following information that will be introduced. However, there are certain sentences that quite confused me, for instance the sentence “… trial 5 had a reaction rate just a little bit higher than trial 5 and collected more gas” maybe this is only a typographical error but it still causes confusion thus rechecking must be done thoroughly. Moreover, their conclusion about the essential oils disordered my understanding a bit, stated in the last part of their summary that they rejected the hypothesis about essential oils have antifungal properties so I have to reread again from the start to confirm if I overlooked it because their hypothesis is clearly stated in the introduction saying “The hypothesis of this experiment is alternating the proportion of yeasts and sugar and adding essential oil will not affect the rate of fermentation and the amount of CO2 produced”. Although this is discussed by comparing the result of the experiment to existing information, I think it’s not appropriate to reject a hypothesis without including it on the correct part of the paper first.
The aim of the study is to identify which factor affects the rate of fermentation of solutions- which was achieved by the results from the experiment. The study is a good tool in describing the basic kinetics of enzyme but I think further process must be made to make the study more accurate that will describe deep characteristics and principles of enzyme kinetics.
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This is my second article that is also about fermentation, it's just a coincidence that I happen to picked this topic haha.
hirap ako tapusin to kanina ewan ko ba, mini heart attacked nga eh kasi nakatulog ako pag gising ko kala ko alas dose na eh 11:59 pm today deadline neto buti natapos at submit ko pa haha.
you can used this critiqued paper as a basis if ever you'll have a homework or project about critique paper, thanks for stopping by <3 <3
Good nightuee~~
