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.
Answer:
<em>Tiktaalik roseae</em>
Explanation:
The discovery of the fossil, <em>Tiktaalik roseae</em> on a Canadian island gives credence to the fact that animals moved from living in water to living on dry land. This fish which has feature of land animals such as a neck, skull, and ribs is believed to have lived some 375 million years ago. It also has features of fish such as the fins and scales.
The discovery of this fossil is important to scientists because it confirmed their believe that there should be an organism that would prove that life transitioned from water to land. The fossil was discovered in the year 2004.
