The correct answer is option (C) One student measures liquids for the experiment by holding the flask up at eye level. The other student measures liquids for the experiment while the flask sits on the table. Measuring liquids by holding the flask at eye level is the greatest amount of error in the experiment.
When liquid is being measured in a flask, the liquid shows a curve downwards which is called the meniscus. For measuring the transparent liquids, the lower meniscus touching the graduation of the should be considered and for measuring the colored liquids, the upper meniscus touching the graduation of the flask should be considered. When, the measurement is done by holding the flask at eye level there is always an error as it should be kept on a flat surface and measured by eyes directly leveling with the liquid. This gives a correct measurement which was done by the other student. Thus, one student measuring the liquid by holding the flask at eye level will have a wrong measurement and the other student measuring the liquid while the flask sits on the table gives the correct measurement and the results of the experiment will vary.
Answer:
Explanation:
Normally, under anaerobic condition in yeast, pyruvate produced from glycolysis leads to the production of ethanol as shown below.
pyruvate ⇒ acetaldehyde + NADH ⇒ ethanol + NAD
The pyruvate is converted to acetaldehyde by the enzyme, pyruvate decarboxylase. It should be NOTED that carbon dioxide is released in this step. The acetaldehyde produced in the "first step" is then converted to ethanol by the enzyme alcohol dehydrogenase. It must be noted from the above that the steps are irreversible.
If a mutated strain of yeast is unique because it does not produce alcohol and lactic acid (which is referred to as toxic acid in the question); thus having a high level of pyruvate because of the presence of a novel enzyme. <u>The function of this novel enzyme will most likely be the conversion of acetaldehyde in the presence of carbondioxide back to pyruvate; thus making that step reversible</u>. This could be a possible explanation for the high level of pyruvate present in the yeast.
