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.
epithelial stomach cell>stomach lining tissue>stomach>disgestive system
<h2>DNA </h2>
Explanation:
1) Experiment done by Griffith:
- Griffith used two related strains of bacteria, known as R and S
- R bacteria were nonvirulent, meaning that they did not cause sickness when injected into a mouse whereas mice injected with live S bacteria developed pneumonia and died
- Griffith tried injecting mice with heat-killed S bacteria (that is, S bacteria that had been heated to high temperatures, causing the cells to die), the heat-killed S bacteria did not cause disease in mice
- When harmless R bacteria were combined with harmless heat-killed S bacteria and injected into a mouse, not only did the mouse developed disease and died, but when Griffith took a blood sample from the dead mouse, he found that it contained living S bacteria
- Griffith concluded that the R-strain bacteria must have taken up what he called a transforming principle from the heat-killed S bacteria, which allowed them to transform into smooth-coated bacteria and become virulent
2) Experiment done by Avery:
- Avery, McCarty and MacLeod set out to identify Griffith's transforming principle
- They began with large cultures of heat-killed S cells and, through a long series of biochemical steps progressively purified the transforming principle by washing away, separating out, or enzymatically destroying the other cellular components
- These results all pointed to DNA as the likely transforming principle but Avery was cautious in interpreting his results
- He realized that it was still possible that some contaminating substance present in small amounts, not DNA, was the actual transforming principle
3) Experiment done by Hershey and Chase:
- Hershey and Chase studied bacteriophage, or viruses that attack bacteria
- The phages they used were simple particles composed of protein and DNA, with the outer structures made of protein and the inner core consisting of DNA
- Hershey and Chase concluded that DNA, not protein, was injected into host cells and made up the genetic material of the phage
Answer:
Question is not presented
Explanation:
True :) Aristotle supported the idea of an atom
