Question

POST-LAB QUESTIONS 1. Based on the results of the three tests, how do you kno the fruit was DNA and not protein? Explain. 2. What happened to the egg white sample, containing mostly protein, when you heated it or oered the pH? Explain what you saw and what you think was happening at the molecular level. 3. Why does the DNA double helix unravel when exposed to high temperatures or acidic conditions? If you tried to run this experiment with a piece of meat (animal cells) instead of fruit 4. (plant cells), what would you expect the results for the three tests to be? Explain.

Answer 1

1. When an ice-cold alcohol is added to a extracted sample, the DNA precipitates out of solution that we could observed when we see a stringy white mass. This confirm that extracted sample is DNA.

2. When the white portion of the egg, get heated and pH is lowered, then its structure its distorted . This is happening because at the molecular level, egg white is a protein, that have specific 3D structure which get changed when we either changed the temperature and change the pH because proteins work at specific temperature and pH.

3. DNA double helix unreveal when exposed to high temperature or acidic condition because DNA helix are bonded by hydrogen bonds between nitrogenous bases. As, the temperature become high or come in acidic condition, the hydrogen bonds break and helix get unreveal.

4. if the test run on the meat, instead of plant cell then the DNA sample would be more in amount as in plant cell it is difficult to extract DNA because of having cell wall.